Australian Geckos and Pygopods In Captivity 0987244736

Table of contents :
Cover
Title
Copyright
CONTENTS
ABOUT THE AUTHOR
INTRODUCTION
GENERAL MANAGEMENT
PET SUITABILITY
CHOOSING YOUR STOCK
Selecting an Individual Gecko
HANDLING AND HYGIENE
Geckos
Pygopods
TRANSPORTATION
Short Journeys
Long Journeys
Timber Boxes
Plastic Containers
PURCHASE AND FREIGHT ETIQUETTE
Buyers
Sellers
LEGAL REQUIREMENTS
GENERAL SAFETY
SECURITY
QUARANTINE
HOUSING
INDOOR ENCLOSURES
Rack Systems
Tubs
Tanks
Timber Enclosures
Glass, Perspex or Plastic Moulded Commercial Terrariums
Mesh Terrariums
OUTDOOR ENCLOSURES
Pits
Aviaries
ENCLOSURE SIZE
Minimum Enclosure Sizes
COMPATIBILITY
VENTILATION
SUBSTRATE
Sand
Soil
Gravel
Scoria
Leaf Litter
Potting Mix
Sphagnum Moss
Peat
Bark and Wood Chip
Wood Shavings
Corn Cob Litter
Walnut Shell Litter
Alfalfa/Lucerne Pellets
Compressed Timber Pellets
Compressed Newspaper Pellets
Zeolite and Clumping Cat Litter
Paper
Artificial Grass
Indoor/Outdoor Carpet
HIDE SITES
Vertical Hide Sites
Horizontal Hide Sites
ENCLOSURE ENRICHMENT
Surface Litter
Branches and Hollows
Artificial Plants
Dried Plants
Live Plants
HEATING
HEAT CORD OR TAPE
HEAT MATS
HEAT ROCKS
CERAMIC HEATERS
GLOBES
Standard Incandescent Globes
Reflector Globes
Reptile Lamps
Halogen Bulbs
Infrared Globes
Mercury Vapour Lamps (MVLs)
LIGHTING
THE SCIENCE OF LIGHTING
Visible Light
Infrared
Ultraviolet A (UV-A)
Ultraviolet B (UV-B)
Ultraviolet C (UV-C)
LIGHTING OPTIONS
UV-B Emitting Fluorescent Tubes
Black Lights
Compact UV-B Emitting Lamps
Mercury Vapour Lamps
THERMOSTATS
Probe Thermostats
On/Off Thermostats
Dimming Thermostats
Pulse Proportional Thermostats
HUMIDITY
FEEDING METHODS AND NUTRITION
INVERTEBRATE FOOD ITEMS
Crickets—Acheta domestica
Cockroaches
Mealworms—Tenebrio molitor
King Mealworms or Superworms—Zophobas morio
Maggots/Flies/Pupae—Musca vetutissima
Slaters
Silkworms—Bombyx mori and other Caterpillars
Termites
Earthworms—Lumbricus terrestrius
Locusts—Chortoicetes terminifera
Spiders
Fruit Flies—Drosophila species
Snails—Helix aspersa and other species
Waxworms—Galleria mellonella
Wild Fodder
Nutritional Data Averages for Invertebrate Diets
VERTEBRATE FOOD ITEMS
Rats and Mice
Fish
Reptiles
Nutritional Data Averages for Vertebrate Diets
ARTIFICIAL DIETS
CULTURING INSECT FOOD ITEMS
Crickets—Acheta domestica
Speckled Feeder Roaches—Nauphoeta cinerea
Locusts—Choroicetes terminifera
Bush Flies—Musca vetutissima
Slaters
Lesser Waxworms (Indian Meal Moths)—Plodia interpunctella
Fruit Fly/Vinegar Fly/Ferment Fly—Drosophila species
DIETARY SUPPLEMENTS
CALCIUM
Gut Loading
Dusting
PROTEIN
FEEDING FACILITIES
FEEDING PROBLEMS
TREATMENT
Assist Feeding
Force Feeding
Tube Feeding
BREEDING
VISUAL SEXING
Colour
Size
Femoral and Preanal Pores
Hemipenal Bulges
Paracloacal Spur Structures
OTHER SEXING TECHNIQUES
Hemipenal Popping
Hemipenal Transillumination
Hemipenal Observation
BREEDING AGE
COURTSHIP
MATING
STRATEGIES TO ENHANCE BREEDING SUCCESS
COOLING
SEPARATION
REPRODUCTION
REPRODUCTIVE STRATEGIES
EGG TYPE
CLUTCH SIZE
BREEDING FREQUENCY
GRAVIDITY
CARING FOR BREEDING FEMALE GECKOS AND PYGOPODS
NEST FACILITIES
ARBOREAL SPECIES
TERRESTRIAL SPECIES
EGG LAYING
EGG MANAGEMENT
Collecting and Handling
Determining Egg Viability
ARTIFICIAL INCUBATION
INCUBATION FACILITIES
CONTAINERS
HEATING
TEMPERATURE CONTROL
INCUBATION MEDIUM
Vermiculite
Perlite
Sphagnum Moss
True Peat Moss
Coir Peat Moss
Sand
No Substrate
INCUBATION REGIMES
TEMPERATURE DEPENDENT SEX DETERMINATION
TYPES OF TEMPERATURE DEPENDENT SEX DETERMINATION IN GECKO SPECIES
NATURAL INCUBATION
HATCHLING CARE
FEEDING
Feeding Frequency
Supplementation
LIGHTING
HOUSING
HEATING
COMPATIBILITY
COMMON DISEASES AND DISORDERS
DISCLAIMER
NUTRITIONAL DISORDERS
OBESITY
METABOLIC BONE DISEASE (CALCIUM/VITAMIN D3 DEFICIENCY)
Early Onset Metabolic Bone Disease
Late Onset Metabolic Bone Disease
Delayed Metabolic Bone Disease
Floppy Tail Syndrome
Reproductive Metabolic Bone Disease
GUT IMPACTION
PARASITIC DISORDERS
INTERNAL PARASITES
EXTERNAL PARASITES
SKIN DISORDERS
DYSECDYSIS
SCALE ROT
NAIL, TOE AND LIMB DISORDERS
EYE DISORDERS
EYE TRAUMA
PHOTO-KERATOCONJUNCTIVITIS
PRIMARY BACTERIAL EYE INFECTIONS
RESPIRATORY DISORDERS
BACTERIAL PNEUMONIA
VITAMIN A DEFICIENCY
HUMIDITY RELATED PROBLEMS
PARASITIC PNEUMONIA
TRAUMA
BITE INJURIES
THERMAL BURNS
REPRODUCTIVE DISORDERS
PRE-OVULATORY AND POST-OVULATORY STASIS (EGG BINDING OR DYSTOCIA)
UTERINE INFECTION
HEMIPENAL INJURIES AND INFECTION
CONGENITAL DEFECTS
NASAL AND ORAL DISORDERS
NASAL ABRASIONS—NOSE RUBS
JAW DISEASE/PERIODONTITIS/STOMATITIS
ADMINISTRATION OF MEDICATIONS
Subcutaneous or Intramuscular Injections
Liquid Oral Medication
Oral Tablet Medication
MAKING THE MOST OF YOUR REPTILE VETERINARIAN
SPECIES
BYNOE’S GECKOS AND DESERT CAVE GECKOS
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR BYNOE’S GECKO AND DESERT CAVE GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
PRONUNCIATION
DTELLAS AND HOUSE GECKOS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR DTELLA AND HOUSE GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
GIANT CAVE AND GIANT TREE GECKOS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR GIANT CAVE AND TREE GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
KNOB-TAILED GECKOS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR KNOB-TAILED GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
LEAF-TAILED GECKOS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR LEAF-TAILED GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
SMALL ARBOREAL GECKOS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR SMALL ARBOREAL GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
RING-TAILED GECKOS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR RING-TAILED GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
SMALL TERRESTRIAL GECKOS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR SMALL TERRESTRIAL GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
THICK-TAILED GECKOS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR THICK-TAILED GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
VELVET GECKOS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR VELVET GECKO SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
PYGOPODS—FLAP FOOTED LIZARDS
PRONUNCIATION
DESCRIPTION
ADULTS
JUVENILES
SEXING
SUBSPECIES
IN THE WILD
DISTRIBUTION AND HABITAT
IN CAPTIVITY
STATUS
HOUSING
INDOOR ENCLOSURES
Summary
OUTDOOR ENCLOSURES
COMPATIBILITY
FEEDING
BREEDING
INCUBATION AND HATCHLING DEVELOPMENT
BREEDING RECORDS FOR PYGOPOD SPECIES
HYBRIDISATION AND COLOUR VARIANTS
LONGEVITY
ACKNOWLEDGEMENTS
AUSTRALIAN HERPETOLOGICAL SOCIETIES AND USEFUL WEBSITES
HERPETOLOGICAL SOCIETIES
OTHER USEFUL WEBSITES
BIBLIOGRAPHY
PRINTED LITERATURE
ONLINE RESOURCES
GLOSSARY
NOTES
Backcover

Citation preview

A Guide to…

Australian

GECKOS & PYGOPODS

in Captivity By Dr Danny Brown BVSc (Hons) BSc (Hons)

Edited and Published by Reptile Publications © 2012 page 1

©Reptile Publications 2012 Reptile Publications PO Box 2330 Burleigh BC QLD 4220 Australia www.reptilepublications.com [email protected] ISBN 978 0 9872447 3 4 ISBN 978-0-9758200-6-3 (Ebook) All rights reserved. No part of this publication may be reproduced, stored in any retrieval system, or transmitted in any form or by any means without the prior permission in writing of the publisher.

COVER PHOTOGRAPHS FRONT COVER Top Left Oedura marmorata G SCHMIDA Middle Left Diplodactylus galeatus G SCHMIDA Bottom Left Pygopus lepidopodus J VOS Bottom Right Underwoodisaurus milii G STEPHENSON Bottom (Main Photograph) Saltuarius swaini G SCHMIDA   BACK COVER Top Cyrtodactylus tuberculatus G SCHMIDA Bottom Rhynchoedura ornata J VOS Disclaimer: Very few drugs are registered for use in reptiles, and most usages and dose rates have been extrapolated from mammalian therapeutics. Everyone using medications should be aware that manufacturers of these drugs will not accept any responsibility for the ‘off-label’ use of their drugs. The dose rates and information are based on clinical trials and practical experience, but unrecorded adverse side effects may occur. Where possible, the author has provided brand names for the drugs mentioned. These should not be taken as a recommendation for one particular brand over another, but rather as a starting point for you to find the drug of your choice. In most instances, contraindications and side effects are not listed. This should not be taken to mean that there are none—many of these drugs have not been used extensively, and reports on contraindications and side effects are not recorded at date of publication.

reptile

publications Design, Type and Art: e design ©ABK/Reptile Publications 2012

page 2

CONTENTS ABOUT THE AUTHOR.....................................................................................................................................16 ACKNOWLEDGEMENTS..................................................................................................................................................17

INTRODUCTION................................................................................................................................................................19 GENERAL MANAGEMENT PET SUITABILITY............................................................................................................................................................................................20 CHOOSING YOUR STOCK ...............................................................................................................................................................20 Selecting an Individual Gecko...................................................................................................................................................21 HANDLING AND HYGIENE.............................................................................................................................................................22 Geckos................................................................................................................................................................................................................................22 Pygopods......................................................................................................................................................................................................................24 TRANSPORTATION.....................................................................................................................................................................................25 Short Journeys.....................................................................................................................................................................................................25 Long Journeys.......................................................................................................................................................................................................27 Timber Boxes...........................................................................................................................................................................................................28 Plastic Containers............................................................................................................................................................................................28 PURCHASE AND FREIGHT ETIQUETTE...................................................................................................................29 Buyers.................................................................................................................................................................................................................................29 Sellers..................................................................................................................................................................................................................................30 LEGAL REQUIREMENTS.....................................................................................................................................................................30 GENERAL SAFETY.........................................................................................................................................................................................32 SECURITY.....................................................................................................................................................................................................................32 QUARANTINE.......................................................................................................................................................................................................33

HOUSING INDOOR ENCLOSURES...................................................................................................................................................34

Rack Systems...........................................................................................................................................................................................................34 Tubs........................................................................................................................................................................................................................................34 Tanks.....................................................................................................................................................................................................................................35 Timber Enclosures..........................................................................................................................................................................................35 Glass, Perspex or Plastic Moulded Commercial Terrariums.......................................................35 Mesh Terrariums................................................................................................................................................................................................37

OUTDOOR ENCLOSURES.........................................................................................................................................37

Pits............................................................................................................................................................................................................................................38 Aviaries.............................................................................................................................................................................................................................38 ENCLOSURE SIZE...........................................................................................................................................................................................39 Minimum Enclosure Sizes..................................................................................................................................................................39 page 3

COMPATIBILITY................................................................................................................................................................................................40 VENTILATION.......................................................................................................................................................................................................40 SUBSTRATE..............................................................................................................................................................................................................41 Sand.......................................................................................................................................................................................................................................41 Soil............................................................................................................................................................................................................................................42 Gravel...................................................................................................................................................................................................................................42 Scoria....................................................................................................................................................................................................................................42 Leaf Litter......................................................................................................................................................................................................................42 Potting Mix.................................................................................................................................................................................................................43 Sphagnum Moss................................................................................................................................................................................................43 Peat.........................................................................................................................................................................................................................................43 Bark and Wood Chip...................................................................................................................................................................................43 Wood Shavings....................................................................................................................................................................................................44 Corn Cob Litter.....................................................................................................................................................................................................44 Walnut Shell Litter..........................................................................................................................................................................................44 Alfalfa/Lucerne Pellets............................................................................................................................................................................44 Compressed Timber Pellets............................................................................................................................................................44 Compressed Newspaper Pellets..............................................................................................................................................44 Zeolite and Clumping Cat Litter..............................................................................................................................................44 Paper.....................................................................................................................................................................................................................................44 Artificial Grass.......................................................................................................................................................................................................45 Indoor/Outdoor Carpet.........................................................................................................................................................................45

HIDE SITES........................................................................................................................................................................................................45 Vertical Hide Sites...........................................................................................................................................................................................45 Horizontal Hide Sites.................................................................................................................................................................................46

ENCLOSURE ENRICHMENT....................................................................................................................................47 Surface Litter...........................................................................................................................................................................................................47 Branches and Hollows.............................................................................................................................................................................47 Artificial Plants.....................................................................................................................................................................................................48 Dried Plants...............................................................................................................................................................................................................48 Live Plants....................................................................................................................................................................................................................49

HEATING................................................................................................................................................................................................................50 HEAT CORD OR TAPE...............................................................................................................................................................................50 HEAT MATS...............................................................................................................................................................................................................51 HEAT ROCKS...........................................................................................................................................................................................................52 CERAMIC HEATERS....................................................................................................................................................................................52 GLOBES...........................................................................................................................................................................................................................52 Standard Incandescent Globes.................................................................................................................................................52 Reflector Globes................................................................................................................................................................................................53 Reptile Lamps........................................................................................................................................................................................................53 Halogen Bulbs.......................................................................................................................................................................................................53 Infrared Globes....................................................................................................................................................................................................54 Mercury Vapour Lamps (MVLs)...............................................................................................................................................54 page 4

LIGHTING.............................................................................................................................................................................................................55 THE SCIENCE OF LIGHTING........................................................................................................................................................55 Visible Light...............................................................................................................................................................................................................55 Infrared.............................................................................................................................................................................................................................55 Ultraviolet A (UV-A)......................................................................................................................................................................................55 Ultraviolet B (UV-B).......................................................................................................................................................................................56 Ultraviolet C (UV-C).......................................................................................................................................................................................58 LIGHTING OPTIONS..................................................................................................................................................................................58 UV-B Emitting Fluorescent Tubes..........................................................................................................................................59 Black Lights................................................................................................................................................................................................................60 Compact UV-B Emitting Lamps................................................................................................................................................60 Mercury Vapour Lamps..........................................................................................................................................................................61

THERMOSTATS....................................................................................................................................................................................61

Probe Thermostats........................................................................................................................................................................................62 On/Off Thermostats.....................................................................................................................................................................................62 Dimming Thermostats.............................................................................................................................................................................62 Pulse Proportional Thermostats.............................................................................................................................................62

HUMIDITY........................................................................................................................................................................................................63

FEEDING METHODS AND NUTRITION INVERTEBRATE FOOD ITEMS.......................................................................................................................65

Crickets—Acheta domestica..................................................................................................................................................................65 Cockroaches.............................................................................................................................................................................................................65 Mealworms—Tenebrio molitor..........................................................................................................................................................66 King Mealworms or Superworms—Zophobas morio..................................................................................66 Maggots/Flies/Pupae—Musca vetutissima...................................................................................................................67 Slaters..................................................................................................................................................................................................................................67 Silkworms—Bombyx mori and other caterpillars.............................................................................................67 Termites...........................................................................................................................................................................................................................68 Earthworms—Lumbricus terrestrius............................................................................................................................................68 Locusts—Chortoicetes terminifera..................................................................................................................................................68 Spiders...............................................................................................................................................................................................................................68 Fruit Flies—Drosophila species......................................................................................................................................................69 Snails—Helix aspersa and other species..........................................................................................................................69 Waxworms—Galleria mellonella.....................................................................................................................................................69 Wild Fodder...............................................................................................................................................................................................................69 Nutritional Data Averages for Invertebrate Diets......................................................................................70

VERTEBRATE FOOD ITEMS.................................................................................................................................71

Rats and Mice.........................................................................................................................................................................................................71 Fish...........................................................................................................................................................................................................................................71 Reptiles.............................................................................................................................................................................................................................71 Nutritional Data Averages for Vertebrate Diets............................................................................................72 page 5

ARTIFICIAL DIETS........................................................................................................................................................................73 CULTURING INSECT FOOD ITEMS...................................................................................................73

Crickets—Acheta domestica..................................................................................................................................................................73 Speckled Feeder Roaches—Nauphoeta cinerea...................................................................................................76 Locusts—Chortoicetes terminifera..................................................................................................................................................77 Bush Flies—Musca vetutissima..........................................................................................................................................................77 Slaters..................................................................................................................................................................................................................................80 Lesser Waxworms (Indian Meal Moths)—Plodia interpunctella...................................................80 Fruit Fly/Vinegar Fly/Ferment Fly—Drosphila species...........................................................................80

DIETARY SUPPLEMENTS..........................................................................................................................................81 CALCIUM.......................................................................................................................................................................................................................81 Gut Loading..............................................................................................................................................................................................................82 Dusting.............................................................................................................................................................................................................................82 PROTEIN........................................................................................................................................................................................................................83

FEEDING FACILITIES............................................................................................................................................................83 FEEDING PROBLEMS..........................................................................................................................................................85 TREATMENT ...........................................................................................................................................................................................................86 Assist Feeding ......................................................................................................................................................................................................86 Force Feeding.........................................................................................................................................................................................................87 Tube Feeding..........................................................................................................................................................................................................87

BREEDING VISUAL SEXING...................................................................................................................................................................................88

Colour..................................................................................................................................................................................................................................88 Size...........................................................................................................................................................................................................................................88 Femoral and Preanal Pores..............................................................................................................................................................89 Hemipenal Bulges...........................................................................................................................................................................................89 Paracloacal Spur Structures...........................................................................................................................................................90 OTHER SEXING TECHNIQUES..................................................................................................................................................91 Hemipenal Popping....................................................................................................................................................................................91 Hemipenal Transillumination......................................................................................................................................................91 Hemipenal Observation.......................................................................................................................................................................93

BREEDING AGE.....................................................................................................................................................................................93 COURTSHIP....................................................................................................................................................................................................93 MATING....................................................................................................................................................................................................................93 STRATEGIES TO ENHANCE BREEDING SUCCESS...........................................94 COOLING .....................................................................................................................................................................................................................94 SEPARATION..........................................................................................................................................................................................................96 page 6

REPRODUCTION................................................................................................................................................................................96 REPRODUCTIVE STRATEGIES..................................................................................................................................................96 EGG TYPE.....................................................................................................................................................................................................................96 CLUTCH SIZE..........................................................................................................................................................................................................96 BREEDING FREQUENCY....................................................................................................................................................................97 GRAVIDITY................................................................................................................................................................................................................97 CARING FOR BREEDING FEMALE GECKOS AND PYGOPODS .......................................97

NEST FACILITIES................................................................................................................................................................................98 ARBOREAL SPECIES..................................................................................................................................................................................99 TERRESTRIAL SPECIES.........................................................................................................................................................................99

EGG LAYING..............................................................................................................................................................................................101 EGG MANAGEMENT.............................................................................................................................................................................101 Collecting and Handling..................................................................................................................................................................101 Determining Egg Viability.............................................................................................................................................................102

ARTIFICIAL INCUBATION........................................................................................................................................105 INCUBATION FACILITIES..............................................................................................................................................................105 CONTAINERS......................................................................................................................................................................................................106 HEATING....................................................................................................................................................................................................................107 TEMPERATURE CONTROL..........................................................................................................................................................107 INCUBATION MEDIUM.....................................................................................................................................................................108 Vermiculite..............................................................................................................................................................................................................108 Perlite...............................................................................................................................................................................................................................108 Sphagnum Moss............................................................................................................................................................................................108 True Peat Moss.................................................................................................................................................................................................109 Coir Peat Moss .................................................................................................................................................................................................109 Sand...................................................................................................................................................................................................................................109 No Substrate........................................................................................................................................................................................................109 INCUBATION REGIMES....................................................................................................................................................................110 TEMPERATURE DEPENDENT SEX DETERMINATION..................................................................110

NATURAL INCUBATION...............................................................................................................................................112 HATCHLING CARE......................................................................................................................................................................113 FEEDING....................................................................................................................................................................................................................113 Feeding Frequency...................................................................................................................................................................................113 Supplementation.........................................................................................................................................................................................113 LIGHTING.................................................................................................................................................................................................................113 HOUSING..................................................................................................................................................................................................................114 HEATING....................................................................................................................................................................................................................114 COMPATIBILITY............................................................................................................................................................................................114 page 7

COMMON DISEASES AND DISORDERS DISCLAIMER.............................................................................................................................................................................................115 NUTRITIONAL DISORDERS................................................................................................................................115 OBESITY.....................................................................................................................................................................................................................115 METABOLIC BONE DISEASE (CALCIUM/VITAMIN D3 DEFICIENCY)................116 Early Onset Metabolic Bone Disease...........................................................................................................................116 Late Onset Metabolic Bone Disease.............................................................................................................................117 Delayed Metabolic Bone Disease......................................................................................................................................117 Floppy Tail Syndrome...........................................................................................................................................................................118 Reproductive Metabolic Bone Disease....................................................................................................................118 GUT IMPACTION.........................................................................................................................................................................................118

PARASITIC DISORDERS...............................................................................................................................................120 INTERNAL PARASITES......................................................................................................................................................................120 EXTERNAL PARASITES.....................................................................................................................................................................121

SKIN DISORDERS.........................................................................................................................................................................122 DYSECDYSIS.......................................................................................................................................................................................................122 SCALE ROT.............................................................................................................................................................................................................123

NAIL, TOE AND LIMB DISORDERS...................................................................................................124 EYE DISORDERS..............................................................................................................................................................................124 EYE TRAUMA.....................................................................................................................................................................................................124 PHOTO-KERATOCONJUNCTIVITIS.............................................................................................................................124 PRIMARY BACTERIAL EYE INFECTIONS...........................................................................................................125

RESPIRATORY DISORDERS.................................................................................................................................125 BACTERIAL PNEUMONIA............................................................................................................................................................125 VITAMIN A DEFICIENCY................................................................................................................................................................125 HUMIDITY RELATED PROBLEMS...................................................................................................................................125 PARASITIC PNEUMONIA ............................................................................................................................................................126

TRAUMA.............................................................................................................................................................................................................126 BITE INJURIES..................................................................................................................................................................................................126 THERMAL BURNS......................................................................................................................................................................................127

REPRODUCTIVE DISORDERS........................................................................................................................127 PRE-OVULATORY AND POST-OVULATORY STASIS (EGG BINDING OR DYSTOCIA)...........................................................................................................................................127 UTERINE INFECTION...........................................................................................................................................................................129 HEMIPENAL INJURIES AND INFECTION...........................................................................................................129 CONGENITAL DEFECTS...................................................................................................................................................................130 page 8

NASAL AND ORAL DISORDERS..............................................................................................................132 NASAL ABRASIONS—NOSE RUBS.............................................................................................................................132 JAW DISEASE/PERIODONTITIS/STOMATITIS.........................................................................................133

ADMINISTRATION OF MEDICATIONS....................................................................................133 SUBCUTANEOUS OR INTRAMUSCULAR INJECTIONS.............................................................133 Liquid Oral Medication.......................................................................................................................................................................134 Oral Tablet Medication.......................................................................................................................................................................136

MAKING THE MOST OF YOUR REPTILE VETERINARIAN.........136

SPECIES BYNOE’S GECKO AND DESERT CAVE GECKO PRONUNCIATION......................................................................................................................................................................................139

DESCRIPTION...............................................................................................................................................................................139

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................139

IN THE WILD......................................................................................................................................................................................143

DISTRIBUTION AND HABITAT............................................................................................................................................143  

IN CAPTIVITY................................................................................................................................................................................145 STATUS.........................................................................................................................................................................................................................145

HOUSING........................................................................................................................................................................................................145 INDOOR ENCLOSURES.....................................................................................................................................................................146 Summary....................................................................................................................................................................................................................147 OUTDOOR ENCLOSURES.............................................................................................................................................................147 COMPATIBILITY............................................................................................................................................................................................148

FEEDING...........................................................................................................................................................................................................148 BREEDING....................................................................................................................................................................................................148 INCUBATION AND HATCHLING DEVELOPMENT...............................................................................149 BREEDING RECORDS FOR BYNOE’S GECKO AND DESERT CAVE GECKO SPECIES.........................................................................................................................................149 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................150 LONGEVITY..........................................................................................................................................................................................................150 ACKNOWLEDGEMENTS.................................................................................................................................................................150

DTELLAS AND HOUSE GECKOS PRONUNCIATION......................................................................................................................................................................................151

DESCRIPTION...............................................................................................................................................................................152

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................152 page 9

IN THE WILD......................................................................................................................................................................................156 DISTRIBUTION AND HABITAT............................................................................................................................................156  

IN CAPTIVITY................................................................................................................................................................................158

STATUS.........................................................................................................................................................................................................................158

HOUSING........................................................................................................................................................................................................158 INDOOR ENCLOSURES.....................................................................................................................................................................158 Summary....................................................................................................................................................................................................................159 OUTDOOR ENCLOSURES.............................................................................................................................................................159 COMPATIBILITY............................................................................................................................................................................................160

FEEDING...........................................................................................................................................................................................................160 BREEDING....................................................................................................................................................................................................160 INCUBATION AND HATCHLING DEVELOPMENT...............................................................................163 BREEDING RECORDS FOR DTELLA AND HOUSE GECKO SPECIES ...................163 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................164 LONGEVITY..........................................................................................................................................................................................................164 ACKNOWLEDGEMENTS.................................................................................................................................................................164

GIANT CAVE AND GIANT TREE GECKOS

PRONUNCIATION......................................................................................................................................................................................165

DESCRIPTION...............................................................................................................................................................................165

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................165

IN THE WILD......................................................................................................................................................................................169

DISTRIBUTION AND HABITAT............................................................................................................................................169  

IN CAPTIVITY................................................................................................................................................................................171

STATUS.........................................................................................................................................................................................................................171

HOUSING........................................................................................................................................................................................................171

INDOOR ENCLOSURES.....................................................................................................................................................................171 Summary....................................................................................................................................................................................................................173 OUTDOOR ENCLOSURES.............................................................................................................................................................173 COMPATIBILITY............................................................................................................................................................................................173

FEEDING...........................................................................................................................................................................................................173 BREEDING....................................................................................................................................................................................................174

INCUBATION AND HATCHLING DEVELOPMENT...............................................................................175 BREEDING RECORDS FOR GIANT CAVE AND GIANT TREE GECKO SPECIES................................................................................................................................................175 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................176 LONGEVITY..........................................................................................................................................................................................................176 ACKNOWLEDGEMENTS.................................................................................................................................................................176 page 10

KNOB-TAILED GECKOS PRONUNCIATION......................................................................................................................................................................................178

DESCRIPTION...............................................................................................................................................................................178

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................178

IN THE WILD......................................................................................................................................................................................185

DISTRIBUTION AND HABITAT............................................................................................................................................185  

IN CAPTIVITY................................................................................................................................................................................187

STATUS.........................................................................................................................................................................................................................187

HOUSING........................................................................................................................................................................................................187 INDOOR ENCLOSURES.....................................................................................................................................................................188 Summary....................................................................................................................................................................................................................190 OUTDOOR ENCLOSURES.............................................................................................................................................................190 COMPATIBILITY............................................................................................................................................................................................191

FEEDING...........................................................................................................................................................................................................191 BREEDING....................................................................................................................................................................................................192 INCUBATION AND HATCHLING DEVELOPMENT...............................................................................193 BREEDING RECORDS FOR KNOB-TAILED GECKO SPECIES ...........................................194 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................195 LONGEVITY..........................................................................................................................................................................................................198 ACKNOWLEDGEMENTS.................................................................................................................................................................198

LEAF-TAILED GECKOS PRONUNCIATION......................................................................................................................................................................................199

DESCRIPTION...............................................................................................................................................................................204

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................204

IN THE WILD......................................................................................................................................................................................208

DISTRIBUTION AND HABITAT............................................................................................................................................208  

IN CAPTIVITY................................................................................................................................................................................210

STATUS.........................................................................................................................................................................................................................210

HOUSING........................................................................................................................................................................................................212 INDOOR ENCLOSURES.....................................................................................................................................................................212 Summary....................................................................................................................................................................................................................213 OUTDOOR ENCLOSURES.............................................................................................................................................................213 COMPATIBILITY............................................................................................................................................................................................213

FEEDING...........................................................................................................................................................................................................214 BREEDING....................................................................................................................................................................................................215 page 11

INCUBATION AND HATCHLING DEVELOPMENT...............................................................................216 BREEDING RECORDS FOR LEAF-TAILED GECKO SPECIES...............................................217 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................217 LONGEVITY..........................................................................................................................................................................................................217 ACKNOWLEDGEMENTS.................................................................................................................................................................217

SMALL ARBOREAL GECKOS PRONUNCIATION......................................................................................................................................................................................218

DESCRIPTION...............................................................................................................................................................................224

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................224

IN THE WILD......................................................................................................................................................................................232

DISTRIBUTION AND HABITAT............................................................................................................................................232  

IN CAPTIVITY................................................................................................................................................................................233

STATUS.........................................................................................................................................................................................................................233

HOUSING........................................................................................................................................................................................................234 INDOOR ENCLOSURES.....................................................................................................................................................................234 Summary....................................................................................................................................................................................................................235 OUTDOOR ENCLOSURES.............................................................................................................................................................235 COMPATIBILITY............................................................................................................................................................................................235

FEEDING...........................................................................................................................................................................................................235 BREEDING....................................................................................................................................................................................................236 INCUBATION AND HATCHLING DEVELOPMENT...............................................................................237 BREEDING RECORDS FOR SMALL ARBOREAL GECKO SPECIES............................238 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................239 LONGEVITY..........................................................................................................................................................................................................239 ACKNOWLEDGEMENTS.................................................................................................................................................................239

RING-TAILED GECKOS PRONUNCIATION......................................................................................................................................................................................240

DESCRIPTION...............................................................................................................................................................................240

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................240

IN THE WILD......................................................................................................................................................................................245

DISTRIBUTION AND HABITAT............................................................................................................................................245  

IN CAPTIVITY................................................................................................................................................................................246

STATUS.........................................................................................................................................................................................................................246

HOUSING........................................................................................................................................................................................................246 page 12

INDOOR ENCLOSURES.....................................................................................................................................................................247 Summary....................................................................................................................................................................................................................248 OUTDOOR ENCLOSURES.............................................................................................................................................................248 COMPATIBILITY............................................................................................................................................................................................248

FEEDING...........................................................................................................................................................................................................248 BREEDING....................................................................................................................................................................................................249 INCUBATION AND HATCHLING DEVELOPMENT...............................................................................251 BREEDING RECORDS FOR RING-TAILED GECKO SPECIES...............................................252 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................252 LONGEVITY..........................................................................................................................................................................................................252 ACKNOWLEDGEMENTS.................................................................................................................................................................252

SMALL TERRESTRIAL GECKOS PRONUNCIATION......................................................................................................................................................................................253

DESCRIPTION...............................................................................................................................................................................260

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................260

IN THE WILD......................................................................................................................................................................................264

DISTRIBUTION AND HABITAT............................................................................................................................................264  

IN CAPTIVITY................................................................................................................................................................................266

STATUS.........................................................................................................................................................................................................................266

HOUSING........................................................................................................................................................................................................267 INDOOR ENCLOSURES.....................................................................................................................................................................267 Summary....................................................................................................................................................................................................................267 OUTDOOR ENCLOSURES.............................................................................................................................................................268 COMPATIBILITY............................................................................................................................................................................................268

FEEDING...........................................................................................................................................................................................................268 BREEDING....................................................................................................................................................................................................269 INCUBATION AND HATCHLING DEVELOPMENT...............................................................................270 BREEDING RECORDS FOR SMALL TERRESTRIAL GECKO SPECIES ..................271 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................272 LONGEVITY..........................................................................................................................................................................................................272 ACKNOWLEDGEMENTS.................................................................................................................................................................272

THICK-TAILED GECKOS PRONUNCIATION......................................................................................................................................................................................273

DESCRIPTION...............................................................................................................................................................................275

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................275 page 13

IN THE WILD......................................................................................................................................................................................279

DISTRIBUTION AND HABITAT............................................................................................................................................279  

IN CAPTIVITY................................................................................................................................................................................281

STATUS.........................................................................................................................................................................................................................281

HOUSING........................................................................................................................................................................................................283 INDOOR ENCLOSURES.....................................................................................................................................................................283 Summary....................................................................................................................................................................................................................284 OUTDOOR ENCLOSURES.............................................................................................................................................................284 COMPATIBILITY............................................................................................................................................................................................285

FEEDING...........................................................................................................................................................................................................285 BREEDING....................................................................................................................................................................................................285 INCUBATION AND HATCHLING DEVELOPMENT...............................................................................287 BREEDING RECORDS FOR THICK-TAILED GECKO SPECIES............................................288 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................289 LONGEVITY..........................................................................................................................................................................................................289 ACKNOWLEDGEMENTS.................................................................................................................................................................289

VELVET GECKOS

PRONUNCIATION......................................................................................................................................................................................290

DESCRIPTION...............................................................................................................................................................................300

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................300

IN THE WILD......................................................................................................................................................................................304

DISTRIBUTION AND HABITAT............................................................................................................................................304  

IN CAPTIVITY................................................................................................................................................................................305

STATUS.........................................................................................................................................................................................................................305

HOUSING........................................................................................................................................................................................................305 INDOOR ENCLOSURES.....................................................................................................................................................................305 Summary....................................................................................................................................................................................................................306 OUTDOOR ENCLOSURES.............................................................................................................................................................306 COMPATIBILITY............................................................................................................................................................................................306

FEEDING...........................................................................................................................................................................................................307 BREEDING....................................................................................................................................................................................................307 INCUBATION AND HATCHLING DEVELOPMENT...............................................................................308 BREEDING RECORDS FOR VELVET GECKO SPECIES...................................................................309 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................309 LONGEVITY..........................................................................................................................................................................................................311 ACKNOWLEDGEMENTS.................................................................................................................................................................311 page 14

PYGOPODS—FLAP FOOTED LIZARDS PRONUNCIATION......................................................................................................................................................................................313

DESCRIPTION...............................................................................................................................................................................320

ADULTS, JUVENILES, SEXING, SUBSPECIES.............................................................................................320

IN THE WILD......................................................................................................................................................................................325

DISTRIBUTION AND HABITAT............................................................................................................................................325  

IN CAPTIVITY................................................................................................................................................................................326

STATUS.........................................................................................................................................................................................................................326

HOUSING........................................................................................................................................................................................................328 INDOOR ENCLOSURES.....................................................................................................................................................................328 Summary....................................................................................................................................................................................................................329 OUTDOOR ENCLOSURES.............................................................................................................................................................329 COMPATIBILITY............................................................................................................................................................................................331

FEEDING...........................................................................................................................................................................................................331 BREEDING....................................................................................................................................................................................................334 INCUBATION AND HATCHLING DEVELOPMENT...............................................................................336 BREEDING RECORDS FOR PYGOPOD SPECIES ...................................................................................336 HYBRIDISATION AND COLOUR VARIANTS..................................................................................................337 LONGEVITY..........................................................................................................................................................................................................337 ACKNOWLEDGEMENTS.................................................................................................................................................................337

AUSTRALIAN HERPETOLOGICAL SOCIETIES AND USEFUL WEBSITES HERPETOLOGICAL SOCIETIES...........................................................................................................................................338 OTHER USEFUL WEBSITES........................................................................................................................................................338

BIBLIOGRAPHY PRINTED LITERATURE......................................................................................................................................................................339 ONLINE RESOURCES...........................................................................................................................................................................341

GLOSSARY......................................................................................................................................................................................342

page 15

ABOUT THE AUTHOR

Danny Brown was born in 1970 and has been an avid keeper of birds and reptiles since the age of nine. He completed a Bachelor of Science degree in 1991 with a major in Ethology and Conservation Biology. In 1992, he completed a Zoology degree with Honours in the field of Bird Behaviour. While completing his science degrees, Danny gained extensive experience working in various animal industries as a zookeeper. He also spent 12 years as a veterinary nurse. In 1997, Danny graduated from the University of Queensland with a Bachelor of Veterinary Science degree with first class Honours. Since then, he has worked on the Sunshine Coast, Queensland, Australia, as a small animal veterinarian with a special interest in avian and reptilian medicine also working in a referral role with local zoological parks. In 2002, he completed and passed his examinations and became a member of the Australian College of Veterinary Scientists in the field of Avian Health. He has since swapped private practise and zoo work for a role in emergency veterinary medicine and critical care. Apart from reptiles, Danny’s other passion in life is birds and he has lectured throughout Australia on avian matters. In 1995, he authored the ABK Publications title A Guide to Pigeons, Doves and Quail— Their Management, Care and Breeding and in 1998 completed A Guide to Pheasants and Waterfowl—Their Management, Care and Breeding. One year later in 1999, he was awarded the Literary Achievement Award by the Avicultural Federation of Australia Inc. In 2003, he finished his third book Under the Microscope—Microscope Use and Pathogen Identification in Birds and Reptiles. Danny is presently the federal and state patron of the Pheasant and Waterfowl Society and a member of numerous avicultural societies. His regular columns feature in a number of magazines including Just Finches and Softbill Magazine and Scales and Tails and he contributes articles to various other bird magazines. Under his screen name geckodan, Danny is also a frequent contributor to numerous online reptile forums and discussion groups. Danny also maintains a popular website at www.geckodan.com that educates people on basic reptile care and husbandry. In 2005, Danny and his wife Wendy were blessed with Stuart—a bouncing baby boy with the makings of an obsessive-compulsive animal nut like his father. Stuart keeps Danny busy most days in his role as a stay-at-home dad. In January 2009, the Brown family became busier than ever with the birth of twins Robert and Lachlan. Danny currently maintains one of the largest private lizard collections in Australia. Over the past 25 years he has kept more than 175 species of Australian lizards and bred 80% of these. He currently is keeping and breeding more than 400 specimens of 60+ species of geckos, pygopods, skinks and monitors. In addition, he maintains a collection of 350 birds including finches, waterfowl, native and foreign softbills, quail and pigeons as well as an extensive collection of Australian and New Guinea fish. In the rare moments Danny is not feeding something or working, he maintains an interest in Australian native plants, particularly grevilleas native to Western Australia. page 16

ACKNOWLEDGEMENTS A book of this magnitude cannot be created by just one person. Over the past eight years, many dozens of persons have been pivotal in the development of this text whether it be through the provision of a simple piece of important data, the clarification of field observations or assistance with more significant amounts of information such as questionnaires. I would like to take this opportunity to thank those who have supported me by providing information for this book including—Tremain Anderson, Ken Aplin, Manfred Au, Michael Austin, Ken Bartenfield, Dr Gavin Bedford, Nathan Clout, Henry Cook, Pete Derges, Derek Dunlop (DDReptiles.net), Scott Eipper (Nature 4 You), Adam Elliott, Ryan Ernesti, Glenn Gaikhorst, Mieke Gaikhorst (Armadale Reptile Centre), Lee Grismer, Friedrich Wilhelm Henkel, Grant Husband, Michael Kearney, Robert King, Fred Kraus (Bishop Museum, Hawaii), Casey Lasik, Steve Lee, Jonathon Lucas (Educational Reptile Displays), Jason Luke, Stewart Macdonald (ugmedia.com.au), Dave Mackintosh (Pilbara Pythons), Byron Manning, Brad Maryan, John McGrath (Geckowrangler.com.au), Terry Morley (Adelaide Zoo), Pete Nunn, Paul Oliver, David Peica, Janine Perlman, Rob Porter (Livefoods Unlimited), Sarah Ransom, Gunther Schmida (wwwguntherschmida.com.au), Luke Smith, Glenn Shea (Australian Museum), Neil Sonnemann, Nick Stock, Gary Stokes, Sav Timpano, Simon Treseder, Clark Tucker (clarksgeckos.com), Mark van Ijzendoorn, Richard Wells, Derek Wong (shoeboxreptiles.com) and Richard Zychski. A key component of this book are the images that tell the stories and inspire the readers. I am indebted to the many individuals who assisted with the supply of animals or equipment for photography purposes, the supply of reference photographs or the supply of the images seen in this text. I am particularly grateful to the numerous professional and semi-professional photographers who allowed me access to their photographic libraries to ‘pick and choose’ my preferred images. I would like to thank the following persons—Michael Anthony, Henry Cook, Warren Cossell, Nicole Cronin (CarpetPythons.com.au), Bob Doneley, Scott Eipper (Nature 4 You), Adam Elliott, David Fischer, Glenn Gaikhorst, Karsten Greisshammer, Phoebe Hart, Clint Hill, Bill Love (www.bluechameleon.org/), Jason Luke, Dan Lynch, Stewart Macdonald (ugmedia.com.au), Ryan Mackintosh, Byron Manning, Brad Maryan, John McGrath, Tim Mensforth (Ultimate Reptile Suppliers/URS Wholesale), Marcus Pollard, Tim Portas, Rob Porter (Livefoods Unlimited), Sarah Ransom, Gunther Schmida (wwwguntherschmida.com.au), Gary Stephenson, Matt Summerville, Geoff Volter (Pet Pacific), Jordan Vos, Derek Wong (shoeboxreptiles.com) and Richard Zychski. I would also like to thank ABK Publications and the tireless staff who have put their trust in me to prepare another title for them to publish. The industrious work of the ABK team is to be commended. Finally, I would like to thank my wife Wendy and my sons Stuart, Robert and Lachlan for putting up with my countless hours at the computer, paper strewn office and years of household neglect while working on this text.

page 17

S MACDONALD

Oedura filicipoda

PAGE BREAK

page 18

INTRODUCTION

Australia is blessed with an extremely diverse gecko and pygopod  population. It currently comprises more than 120 species of gecko and more than 40 species of pygopods. The majority of gecko species are small and earthy in colouration, although a small proportion are large and bright in colouration and may display ornate patterning. They are exclusively nocturnal in their habits. Pygopods are generally legless, elongate geckos, greyish or brownish in colouration. Many are diurnal in their habits, whereas others are crepuscular or nocturnal.   More than 95% of gecko and pygopod species are endemic to Australia and have developed in isolation from much of the herpetofauna of the rest of the world. The non endemic genera are shared with nearby New Guinea and parts of south-east Asia. For this reason their habits and peculiarities are unique and therefore much of the information about gecko and pygopod captive care is not relevant to Australian species. The uniqueness of these lizards also make them popular as pets worldwide, with many Australian species among the most widely kept geckos and pygopods worldwide. Despite the fascination with Australian geckos and pygopods, very little literature is available on their care and a lot of literature is based on incorrect assumptions and broad generalisations of their natural requirements. Much of this information has either oversimplified the requirements of a species (leading to later disappointment) or painted a picture of such dismal likelihood of success that it has in fact impeded the progression of gecko culture. It is the intention of this book to approach the keeping of these species from a different perspective. Each genus or unique species has been dealt with individually, with the provided information being derived from my personal experiences and from the experiences of other people who have kept and bred these species. This has been supplemented with relevant natural history information to provide a much more balanced view of the care and breeding of these species. It is an unfortunate fact that many species of Australian reptiles are kept overseas in greater numbers than in their country of origin. While we collectively drool over the many exotic and exciting species of Iguanas, Chameleons, geckos and monitors held in other countries, Australian keepers have managed to overlook many species in their own backyard. It is hoped that the information provided in this book will encourage Australian keepers to look more fervently at what is available now to ensure that it will continue to be available in years to come. Additionally, it is hoped that information provided here will allow overseas enthusiasts to better maintain the stocks of Australian species they currently work with so they will not be permanently lost from their repertoire of available species. The information in this book is hopefully presented in such a way that the keeper is able to access the precise detail required on each genus or species in a logical manner. Peculiarities of individual species are highlighted, rather than generalised, as has been the failing of many books before this one. This book covers all Australian genera that are currently maintained in captivity in moderate numbers at the time of publication (regardless of where in the world they may be maintained). Very rare species are not covered as they are beyond the scope of this text.

page 19

GENERAL MANAGEMENT PET SUITABILITY Geckos and pygopods are considered passive pets. Although some species can be regularly handled, it is not something they enjoy. These species are best considered as display specimens to be observed and enjoyed for their behavioural traits and activities. Their small size, often basic husbandry needs and relatively low set-up costs make them appealing to those with restricted space or novice facilities.

CHOOSING YOUR STOCK There are so many species of lizards to choose from when establishing a collection that it can sometimes be difficult for a beginner to decide which species is best for them. Some things to consider are: Who is the gecko or pygopod for? Certain species are better suited to adults than children. For example, aggressive or delicate species are not recommended for children. Passive pets, such as geckos, may not hold a child’s interest as well as a more interactive species. Why do you want a gecko or pygopod? The intentions you have for a lizard should influence the species you select. Is it to be on display or will it be a handled pet? Few gecko or pygopod species enjoy being handled. Do you really need a gecko or pygopod? You must have the time, space and money to efficiently care for a gecko or pygopod. They require maintenance—some species require daily attention to remain healthy and others require considerable space and expensive food. Selecting the wrong species can leave a new keeper frustrated and disillusioned with the hobby. Can you afford the initial set-up costs? The actual purchase price of a gecko or pygopod is often the smallest portion of the total set-up cost. A new keeper must purchase enclosures, lighting and heating. Different classes of reptiles have different requirements—geckos are among the cheapest to maintain. However, cutting corners during the initial set-up will haunt you later. Can you feed the species properly? Species with broad dietary needs are much easier to cater for. Selecting a species that only dines on insects, such as most geckos, may become a burden if you cannot access or afford a regular source of live food. What sex do you purchase? Generally, a male is the best choice when selecting a single specimen—they are often more active and less inclined to suffer from reproductive disorders. Do you purchase an adult or a juvenile? Many keepers feel that purchasing a juvenile allows them to develop a bond with their pet. The disadvantages of purchasing juveniles are that they may be more difficult to care for and are often sold unsexed. However, they are usually less expensive and initially require simpler husbandry features. Some keepers prefer adults or sub adults—these individuals are already past the difficult stage, are able to be sexed and of a size that allows them to be placed immediately into adult accommodation. page 20

Should you purchase captive bred or legally wild caught? Captive bred specimens are far more reliable than legally wild caught. Captive bred specimens are more inclined to eat commercially available foods, have limited previous exposure to parasites and generally live longer. Legally wild caught specimens may be preferable when purchasing rare species not readily offered for sale. Should you purchase unrelated stock? There is certainly evidence to suggest that long term inbreeding can reduce fertility and health in geckos. Where possible, see if individuals from different parents can be purchased. If not, make sure that you aim to sell unrelated offspring either by maintaining a second unrelated population or by swapping hatchlings with an associate. Who should you purchase from? Dealers and breeders both sell reptiles. Dealers generally have more stock available but fewer species to choose from. They are less able to provide information on the history of the geckos offered for sale and the level of advice varies greatly between each dealership. Breeders are usually able to provide greater individual history but may have limited stock. Some buyers prefer to purchase locally, however, interstate purchases can be rewarding when dealing with breeders who have a good reputation. No matter where you purchase from, make sure the seller provides adequate care instructions—just because an individual has specimens for sale does not necessarily infer any level of expertise. Who will care for your gecko when you are not available? Geckos will tolerate an owner’s absence for a short period of time. However, if a gecko has special needs, these will have to be catered for during any absence.

Selecting an Individual Gecko Once you have determined which species or species group you are interested in keeping, it is time to select a healthy specimen. The following guidelines can be helpful. • Within a group of lizards, select an individual that is bright, alert and active—these are often the most dominant specimens and generally the best feeders. • If possible, observe the specimen’s response to food. Assuming an individual has not recently been fed, it should at least recognise the presence of food—even if your presence is somewhat intimidating. • Check the gecko or pygopod’s movement is free and clear of the ground and that it does not move abnormally compared to others in the group. • Check the gecko or pygopod is breathing normally. Is it breathing through an open mouth—if so it may be suffering from respiratory distress or heat stress. • If possible, handle the specimen to get an indication of its weight and strength. A weak or sickly individual will feel light and will not struggle unduly when handled. • Examine the gecko or pygopod’s physical build. Is the tail fat and rounded? Are the hips protruding? Are the muscles of the face rounded and plump? Avoid underweight specimens. • Inspect the feet and limbs. Missing toes may not affect the health of a lizard but you should be able to negotiate a lower price. Swelling around the feet may indicate infection. • Look down the spine for any obvious changes in symmetry, curvature or bumps. • Check the eyes are bright and that both open simultaneously. • The skin should shed cleanly. Retained sheds may not be significant in a single individual but if multiple specimens within the enclosure have problems, it may indicate overly hot and dry conditions. page 21

• Inspect the tail—is it the original or a modified tail? A modified tail is usually defined by a significant change in the tail colouration and surface features. A modified tail is not a significant issue but some keepers require a perfect tail on a specimen. A modified tail may indicate fighting between individuals, rough handling, wild origins or heat or cold stress. An individual with tail changes is no less healthy than one with a normal tail—but it may demand a lower price. • Check for surface parasites. Inspect the eye sockets and armpits for red mites. Although these parasites are non pathogenic, they can be unsightly. They often occur in specimens housed in outdoor enclosures, in enclosures with natural furnishings such as leaf litter and in wild caught specimens. • Determine if the individual has been sexed. Ask the seller about the sexing method that has been used and, if possible, request that the sexual features be demonstrated to you. • Inspect the gecko or pygopod’s enclosure. Note if the conditions are clean and tidy or if the occupants are overcrowded. • Observe the health of other geckos or pygopods in the collection. Note if the seller appears to possess a genuine knowledge of the specimens in his or her care.

HANDLING AND HYGIENE The use of correct handling techniques when managing geckos and pygopods is necessary to prevent injury to the specimen and to the handler. Most small specimens employ anti-predator mechanisms such as tail dropping—known as tail autotomy—and some also produce irritant secretions. They are more at risk of injury when employing these methods than you.

Geckos

S EIPPER

Most geckos are at much greater risk of injury from a handler than a handler is from them. They possess a number of defence mechanisms that are employed at times of stress, including tail autotomy, besmearing and biting. When overly stressed, many geckos will drop their tail—except rough-type knob-tailed geckos. The tail will regenerate, although it will be less patterned and duller in colour. A regenerated tail does not impact a specimen’s breeding potential, however species that rely on fat deposits inside their tails may lay fewer clutches if food supply is limited in any way after the tail loss. The small arboreal geckos Strophurus possess tail glands that are used to either squirt or besmear their attackers with a sticky, treacle-like secretion that has a sweet, somewhat nutty, but volatile odour. In tail-squirting species, the secretion may be propelled more than 30cm from numerous glands on the tail. Even typically tail-besmearing species such as the Golden-tailed Gecko Strophurus taenicauda can squirt distances of up to 50cm. The secretion dries quickly upon exposure to the air and can irritate eyes or mucous membranes. Tail besmearing is a riskier method of defence, as it must be employed at quite close range. Most geckos have the ability to drop or autotomise their tails at predetermined separation points, as seen in a Phyllurus caudiannulatus

page 22

D BROWN

D BROWN

...which you should avoid getting it in your eye

S EIPPER

Larger gecko species such as Nephrurus, Pseudothecadactylus and Cyrtodactylus can bite quite savagely and may draw blood. Nephrurus species usually bite and release while the other two species bite and hold on. Attempts to prise these geckos off will usually evoke a firmer bite response. A handler may briskly blow into an individual’s mouth to force it to let go—generally it is recommended to Strophurus geckos have the ability to exude an wait for the gecko to release in its own time. irritant from their tail glands The key to correctly handling geckos and avoiding the deployment of these defence mechanisms is to fully support the gecko’s body during handling. Most species may be supported in the palm of the hand with the thumb across the back of the shoulders and the index finger supporting below the chest or with the

Some geckos can bite savagely

page 23

ANON

D BROWN

A technique for handling a gecko

thumb supporting the chest and the index finger across the back. This keeps them restrained while avoiding contact with the tail and being bitten. Some geckos, such as velvet geckos Oedura species and the Ring-tailed Gecko Cyrtodactylus tuberculatus will often defecate when handled and may attempt to twist their bodies during An alternative technique for handling a gecko restraint. An alternative handling method for these species is to enclose them in cupped hands, however this provides little control over their movement. Great care must be taken when handling hatchling geckos—they are particularly prone to tail autotomy. These geckos should be guided into a small container rather than physically handled. Small terrestrial species may be picked up using a tablespoon.

Pygopods At face value, pygopods appear to be quite defenceless and small. However, they have two main defence mechanisms that may be enacted during handling. ‘Flick leaping’ is employed by the smaller species and involves rapidly flexing the tail (which comprises 70% of the body length in most species) backwards and forwards, causing the pygopod to bounce away like a piece of possessed spaghetti. ‘Flick leaping’ is an effective defence mechanism—it occurs in the blink of an eye and requires fancy guesswork and anticipation by the handler to catch the pygopod mid-leap. A small Delma species can cover several metres of ground in less than 20 seconds by ‘flick leaping’—many have been known to successfully ‘flick leap’ out of an open door without being noticed. Once a small pygopod reaches the cover of leaf litter or a clump of grass it can vanish effortlessly. It can be equally difficult to locate a Delma in an enclosure if it doesn’t want to be caught. Larger pygopods are almost sluggish in comparison to Delma species. However, they compensate for this by biting savagely and ‘crocodile rolling’—the Western Hooded Scaly-foot Pygopus nigriceps and Eastern Hooded Scaly-foot Pygopus schraderi will bite the skin between your fingers with precision. The ‘crocodile roll’ strikes fear into most new pygopod owners as it appears the pygopod may tear itself in half—leaving the handler holding just the eviscerated head. However, I am yet to observe a pygopod explode mid-body or even employ tail autotomy during page 24

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a ‘crocodile roll’. The combination of the two defence mechanisms—the ‘crocodile roll’ while biting your finger web—is very effective at forcing a handler to release their grip—the pain is excruciating. The key to handling pygopods is gentle pressure. Once these species are off the ground, their lack of limbs leaves them at a handler’s mercy. Their body should be supported approximately 3–5cm behind the head, using very gentle pressure concentrated downward—similar to when handling a gecko—allowing the tail to hang behind. Attempts to support the tail or place excessive pressure on the body will usually A technique for handling a pygopod initiate a ‘crocodile roll’. If this occurs, loosen your grip and form your hand into a tube shape to allow the individual to spin until it settles down, then reposition your fingers. Pygopods do not like to be held near the head, however you may have little choice when handling aggressive individuals that require restraining. The Burton's Legless Lizard Lialis burtonis is more tolerant of head restraint than other species of pygopod. When handling these pygopods support their head with your thumb, index and middle fingers just behind the level of the ear openings—allowing the body and tail to hang gently, lightly supported by a curled pinkie finger. The entire jaw line is then free to be manipulated open for things such as the placement of a food item. This hold also allows the pygopod to be easily and rapidly released once the item has been positioned. A pygopod is generally restrained for the purposes of sexing or to assist feeding—the latter particularly with the Burton's Legless Lizard L. burtonis. For sexing, I recommend the specimen be placed on a table and one hand, in a tube shape, be used to support the front end of the body. The tail end should sit on the table surface. Almost all specimens will roll initially before settling. The other hand can then be used to elevate the foot flap to examine the paracloacal spurs.

TRANSPORTATION Once you have selected a gecko or pygopod you will have to transport it to its new home. There are two main options with different things to take into consideration—short journeys or longer journeys.

Short Journeys A short journey refers to the movement of a gecko or pygopod within a single facility or between facilities within driving distance of each other. The former is generally for the purposes of pairing, separation, the removal of offspring or pre-sale. The key to safely transporting lizards on short journeys is preparation and the use of safe and secure storage containers appropriate for the species being transported. It is recommended to always have a range of containers stored nearby that can be used in case of an emergency. page 25

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For the transportation of most small species, takeaway food containers purchased in bulk from supermarkets and commercial catering suppliers are suitable. Ventilation holes in the containers are essential—use a soldering iron to melt appropriately sized holes around the perimeter or on the lid. Lunch boxes and various sealed food containers can be treated with much the same method, but these containers take up more A soldering iron can be used to make holes in space. Bags should be avoided for transporting plastic containers without cracking any specimen smaller than 10cm SVL—I have experienced mishaps including escapes, thread entanglements and crushing injuries. Among very small species, I have never experienced issues with aggression between individuals in the same container if the container is an appropriate size. However, when in doubt, opt for one specimen per container. For the transportation of medium sized specimens, larger plastic containers with lockable lids are recommended. Buckets with lids are suitable for use for moving at home. Cardboard mailing tubes with ventilation provided via holes in the plastic caps are also suitable. Bags can be used with appropriately sized individuals but they must be clean, made of lightweight cotton, have all seams turned to the outside and be of an appropriate size—a bag 3 SVL wide x 5 SVL deep is ideal for a single specimen. Rounded corners will help prevent suffocation. A method known as ‘goose necking’ can be used to seal the A range of containers suitable for holding small to bag—simply twist the end of the bag and fold it medium lizards back on itself. Then close it with multiple rubber bands, plastic cable ties or a cloth tie to prevent escapes. When handling species with long tails, ensure the tail tip does not become trapped in the bag opening. For increased security, place the bag inside a plastic tub, small foam esky, cardboard box or bucket. Do not stack the bags—this may limit ventilation for specimens located on the bottom. Tape or clothes pegs can be used to separate bags within a single container. Only one individual should be packed per bag. Be aware of specimens bagged in proximity to each other— predators can still smell prey through bags. When transporting geckos and pygopods by vehicle, precautions must be taken to avoid fluctuating temperatures. Containers must be The correct method of tying a cloth bag, known as ‘goose necking’

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kept out of direct sunlight and positioned to ensure they do not roll around in the vehicle. Clear tubs can act as miniature greenhouses, killing specimens even after minimal exposure to direct sunlight. Temperature fluctuations can be controlled to some degree by placing all containers inside an insulated box such as a polystyrene esky—this also prevents bagged animals from moving around and rolling themselves into the sunlight. On hot days in vehicles where air conditioning is not available, small ice bricks can be placed inside the esky to cool it. These blocks must not be placed directly against the Alternative holding containers for container and should be wrapped in a light towel. Reptiles medium sized lizards should never be left in a closed vehicle. Despite their heat loving nature, they will stress and die if forced to endure consistently high temperatures. Special precautions must be observed for heat sensitive species. Small species should be packed in wet sphagnum moss to provide moisture and to allow the evaporation to cool the local environment.

Long Journeys Due to the wide reach of the internet and telephone, it is not unusual that we may never meet the person we purchase our reptiles from. The long distances involved in many transactions mean that geckos and pygopods are regularly transported via road and air. Transporting lizards by road in Australia is unreliable. In my experience, the only courier services that can be trusted are the few specialist reptile transportation companies in operation. Although other courier companies may accept reptiles, this does not mean their vehicles or drivers are aware of, or prepared for, the special requirements of transporting live reptiles. It is the sole responsibility of the reptile keeper to ensure they follow freight protocols and regulations so that freight companies can continue to provide the services we expect them to. Reptiles should be packaged according to guidelines set down by the International Air Transport Authority (IATA). If all keepers comply with these regulations, minimal problems should arise. When mishaps do occur, keepers must remember they are not the only person freighting items that day. If items are misdirected, temporarily misplaced or flights are cancelled or redirected, items packaged correctly are unmistakable and are far less likely to be misplaced. Lizards are generally quite resilient. With the exception of some heat sensitive species, misplaced specimens will generally cope quite well for the first 24–48 hours. It is very important to maintain a friendly relationship with your local front of counter staff as, although mishaps may not be their direct fault, they are the people who will fix any issues that may arise. In my experience, your attitude towards them significantly impacts their attitude. The basic requirements for the transportation of geckos and pygopods via air freight in Australia (IATA 2005) are— • All containers and bags should contain some type of packing material such as crumpled or shredded paper. • All animals held in a single bag should be of the same size and species. IATA’s recommended packing densities are generally excessive and not recommended for health and safety reasons. The recommendations are the same for when containers are used. Note that the recommendations given are for maximum densities. Therefore, it is more appropriate to calculate the size of a bag or container for a single animal based on the SVL. page 27

SNOUT-VENT LENGTH

BODY WIDTH

MAXIMUM NUMBER PER BAG

MINIMUM BAG SIZE

> 200mm

> 50mm

1

Based on animal size

150–200mm

25–50mm

100–150mm

< 25mm

15 10 30 20

45 x 60cm 30 x 45cm 45 x 60cm 30 x 45cm

< 100mm

< 25mm

30

30 x 45cm

• If the bag is suspended within the container, it must be suspended from both ends and the maximum number of animals should be halved. Boxes must be constructed according to the following criteria:

Timber Boxes • Must be constructed from water resistant fibreboard, hardboard or plywood of a minimum of three ply. • Must have small ventilation holes or ventilation holes screened with wire mesh. • Must have separate ventilation provided in each divider within a multi-compartment container. • May be surrounded by polystyrene to provide insulation. • Must have smooth internal surfaces. • Must be labelled with an approved label indicating the presence of live animals within the container and an approved label indicating the correct orientation of the package.

Plastic Containers

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• Must be constructed of rigid plastic that is capable of supporting the weight of the containers stacked around it—either upright or upside down—without bending, cracking or collapsing. • Must be of a size that allows an animal’s entire ventral surface to have contact with the floor of the container within. • Must have ventilated openings on all sides. • Animals must be contained within a timber box placed inside the plastic container. Geckos and pygopods should be fed no less than six hours before packaging. All reptiles will cool in transit and are unable to digest food during this period.

An internal container should be appropriately padded so that the occupant is comfortable during transport

The internal box should be further padded with shredded paper. The permit should accompany the shipment and be located in a safe place

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Internal containers should include a non-slip surface—slightly moist paper towel or toilet tissue is suitable as it will stick to the container floor and maintain higher humidity, which can be important for very small specimens. For small arboreal specimens, shredded paper is ideal as it provides a lightweight and safe surface to grip on to. It should be packed tight enough to ensure it does not move around within the container but allows the animal to move between the paper strips. For bagged specimens, A suitably constructed and labelled box ready shredded paper is also ideal for supporting the bags for interstate transport and for providing separation between adjacent bags.

PURCHASE AND FREIGHT ETIQUETTE Buying and selling geckos and pygopods can sometimes be a frustrating process. However, most problems can be avoided if buyers and sellers follow some basic commonsense rules.

Buyers • Check your licence conditions before purchase. Make sure your specific licence allows you to keep the species you are enquiring about. • If you have no intention of purchasing an animal, do not put the seller through the process of advising on feeding and housing, supplying photos, organising freight prices and checking flight availability—you will be called a ‘tyre kicker’. Such people are the curse of the reptile scene and force many a breeder underground and to cease advertising. • Do not attempt to undercut other purchasers by offering more than the successful bidder. Apart from being rude, a seller willing to accept this deal could be willing to mislead you about other aspects of the sale. • Do not be late for a face-to-face purchase or advise if you are running late. • Pay promptly. Do not string a buyer along—they will be turning down other potential buyers while they await your payment. Do not expect the seller to ship before the payment has been sighted. • Assume freight will be an additional cost. Sellers rarely advertise freight inclusive prices. • Advise the seller once you have paid. • Advise the seller of your location. Some regions may not have access to air freight and may require a different transportation approach. • Give clear instructions as to when you are able to receive the geckos or pygopods. • Apply for permits immediately—some authorities may be very slow at issuing them. Most sellers will not hold an animal for an extra month because you were late organising your paperwork. • When contacting the seller, supply your full name and a contact phone number. Sellers are not going to write out a permit to your online nickname—they need your details. • Clearly specify to which airport the reptiles are to be sent and the name of the person picking them up. Freight depots will only hand animals over to the person named on the box. • Be contactable at all times 24 hours before the shipment or at least let the seller know the best times to contact you. • Be sure about what you are buying. Do not purchase a hatchling and then complain because it is not of adult size. • Be sure of whether you are buying sexed or unsexed stock. If a species cannot be sexed at the age it is sold or by the person selling it then you purchase at your own risk. page 29

• Attempt to ask all of your questions at once to save time for both parties. If you are not sure about something ask, however sending 27 emails with 27 questions becomes very tedious for the seller. • Communicate with the seller post purchase to let them know when the reptiles have arrived and if you are happy with them. • Provide proof of injury or death. If an animal arrives injured or dead, you must be able to prove this and must inform the seller immediately. I recommend unpacking the reptiles in the car at the airport. If one is dead on arrival, take it in to show the freight counter staff and ask them to provide written proof of its death—they are obliged to do this if the freight consignment was insured. If the animal is injured or unwell, it is your responsibility to provide evidence of time and date such as photographs or a veterinarian report indicating the extent of injuries.

Sellers • Advertise honestly. Negative feedback spreads like wildfire through the herpetological community. • Be prepared before advertising geckos and pygopods for sale. Highly sought after items may sell fast. It is quite disconcerting for a buyer when a seller advertises and then makes the purchaser wait weeks to receive their goods because they did not have what was advertised and were unprepared for the sale process. • Clearly specify the cost of each specimen listed for sale and the price for freight. It is a common misconception among first time buyers that freight is included in the cost. • Do not double sell. If a buyer has committed to a sale, do not on-sell to the person who offers a higher price or can organise permits earlier. If the sale is completed face-to-face, do not sell to the first to arrive if they were not the first to call. Contact the original enquirer to ascertain if they are still committed to the purchase. • Stay contactable. There is nothing more frustrating for a buyer than a seller who cannot be contacted after a sale has been confirmed. • Remove advertisements once an item is sold. • Give the buyer plenty of notice if you cannot freight on the day you had previously organised. Many people leave early from work or organise family members to be available when delivery is expected. It can be helpful if these people are made aware of a change in plans a couple of days in advance. • Package animals and label them correctly. • Be willing to accept returns. If an individual is truly unhappy with a purchase and contacts you within a fair period of time—usually in the first 24 hours—you should be willing to accept the animal back and offer a replacement or a refund. This should be valid in the case of mistaken gender, misidentification of species or obvious life threatening illness. A replacement or refund is not acceptable because of poor decision making on behalf of the buyer or change of mind. • Be willing to offer a replacement or refund in the case of death or injury. If a specimen is injured or dies before the buyer gets it home, or within the first 24 hours after purchase, and the cause was not the buyer’s fault, a reasonable seller will refund the costs or exchange or replace the animal. How much to refund and who accepts further cost should be negotiated between the buyer and seller.

LEGAL REQUIREMENTS The keeping of native animals in Australia and in other countries worldwide is controlled and legislated by various state, regional and federal government authorities. These rules and page 30

regulations are designed to protect animals from being exploited but may vary between locations. Therefore, it is important to understand your legal rights and responsibilities and be aware of the basic requirements in each state. If you follow these rules to the best of your ability, ask questions when you are unsure of anything, and maintain adequate records you should experience few problems. Hobbyists should be aware of the following issues in particular: • It is illegal, without appropriate authority, to take a gecko or pygopod from the wild to keep in captivity. The only exception is if the animal is injured and requires veterinary care. Legislation varies between states—for example, some will allow you to care for an animal for 72 hours without notifying the relevant authority, others will require you be registered with a wildlife rescue organisation to care for the animal. • It is illegal and ecologically irresponsible to release a captive bred gecko or pygopod into the wild unless it is part of an authorised captive breeding program. • Different authorities have different rules concerning which species can be kept without a licence. Licence exempt species still require records to be kept on the animal’s origin. • Most legislation delegates species to varying licence classes according to their difficulty of care. This may not be consistent between authorities—check that you are appropriately licensed before committing to a transaction. • It is the responsibility of the purchaser and seller of any reptile species to be aware of the legal requirements for owning a particular species in the region in which the buyer resides. However, if the seller breaks the law, it does not exempt the buyer from the consequences. • Do not purchase a gecko or pygopod unless you are certain the seller is licensed to sell that species. If in doubt, request licensing information from the local authority. • It is your legal responsibility to ensure all paperwork, such as incoming and outgoing permit records, is up-to-date—penalties often apply if this is not the case. If paperwork is lost, notify the authorities in writing as soon as possible. They will advise you accordingly. • Be aware of expiry dates on licences. Government departments do not necessarily send out reminders to renew. Technically you are unlicensed once your license expires, and are therefore keeping all wildlife in your possession illegally. However, most local authorities understand that mistakes occur. • Many local authorities have rules regarding how long you must hold an animal before resale to prevent individuals on recreational licences from buying and selling commercially. If, for some reason, you must return or sell a specimen before this period is up, most authorities will grant permission to do so—as long as it is not a regular occurrence. • Never trust any advice until it is written on paper. Unfortunately, the first line of contact with many government wildlife departments is a call centre operator—the level of correct advice you receive from these people varies. Often no two operators from the same office will give the same information if it is more complicated than the bare basics. Always insist upon speaking with a ranger if the question relates to a legal issue or concerns your legal right to keep a certain species. Always request where and in what piece of legislation the information provided can be viewed or request that it is put in writing. • Most legislation requires inspections to take place at a mutually acceptable time. Be cooperative and inspectors and rangers should respect that you have commitments that may not be able to be put on hold at short notice. • Most legislation regarding inspections states that ‘inspections should not cause undue stress’— disturbing sleeping animals in their enclosures or during breeding season may be deemed an undue stress. page 31

• Much legislation is subjective and rangers will interpret the rules differently. Interpretations may also vary between regions, which may result in some keepers being disadvantaged, based on their location. If you have asked for advice on a certain topic, request the ranger’s name and make a note of it. If the advice given seems incorrect or varies significantly from your general understanding of the topic, you are within your rights to call another regional office to confirm the information is correct. If the advice is incorrect, it is useful to know who to blame—it may prevent that advice being given out again.

GENERAL SAFETY As a licensee, you become the guardian of any reptiles in your care and are responsible for any injury that your lizard may inflict whether you are present or not. Thankfully, geckos and pygopods fall into the safe category and the main concern when keeping them is preventing zoonotic diseases that pass from animals to humans. Although they are uncommon, they do occur. Basic hygiene is the best way to avoid these issues. Simple steps to minimise safety issues include: • Encourage and insist on hand washing after handling any reptile. A major zoonotic disease is Salmonella and it is often transmitted through faecal contamination. Once you place a gecko or pygopod in another person’s hand, you are required to tell them to wash their hands afterwards— most people are unaware of zoonotic diseases. • Use commonsense when handing a gecko or pygopod to another person. They should posses the skills to hold it properly and should know not to touch it on the nose—particularly important if children are involved. • Keep enclosures of potentially dangerous reptiles locked or in a locked room. • If a bite occurs follow basic first aid instructions. Reptile bites often become infected when a specimen’s teeth become lodged in the skin or from bacterial organisms in the specimen’s mouth. Pseudomonas and Aeromonas bacteria are common oral inhabitants in reptiles and these multiresistant bacteria can be difficult to treat. • Reptiles should be provided with their own utensils. Avoid the temptation to chop up food indoors and bring it out on a household plate—when this plate is brought back to the house it will be carrying a plethora of bacterial organisms. The same applies to storing reptile food bowls in your refrigerator. • Basic commonsense is really all that is needed to avoid safety issues with your reptiles. Be pro-active.

SECURITY It is essential for financial and ecological reasons to keep reptiles in secure environments. Nonendemic species, regardless of their size and nature, should not be allowed to establish in the wild—it may seem like commonsense, but it is surprising how many captive reptiles escape each year. Some basic considerations to improve enclosure security include: • Keep humans out. Children will often be drawn to reptile collections, regardless of their value. Unfortunately, security measures generally only keep honest people out—thieves will always find a way in. • Use locks. These are essential for outside enclosures or enclosures within reach of children. • Tight fitting lids are essential. • Install self-closing doors, particularly in outdoor enclosures and large indoor ones. Springloaded or hydraulic door closers can be used to shut the door tight behind you when you turn around to pick something up. • Close doors. Double check that each door is securely locked, particularly sliding glass doors. page 32

• Replace substandard fittings. Many commercial cages—particularly less expensive imported models—cut costs by using cheap materials. This is particularly evident with ventilation. If features are excessively flexible or appear cheap, they probably are and should be replaced. • Close the housings for electrical wires when not in use. Many commercial tanks have small cord recesses or holes that wires run through. If these are not in use, they should be closed. Computer desk ports, designed for large numbers of wires to pass through, are often used in commercial enclosures but are rarely ever glued in place and will pop out when expanded by heat. • Install safety lanes or porches. These are essential extensions to an outdoor structure and create a door behind a door, which doubles the security when entering. They may be constructed as an entire passageway across the front, rear or centre of a complex or as a single square extension sufficient in size to allow one person to enter, close one door behind them and then enter the main enclosure. • Examine the enclosure in all weather. Depending on the climatic conditions when an enclosure was constructed, there will be some degree of flexing, contraction and expansion that will occur when a cage heats up or cools down—this can loosen doors and expand wire, creating bubbles between screws and rivets. • Examine all furniture before replacing it. Many a reptile has appeared in a rubbish bin after being thrown out with old litter, replaced hollows or cage floor paper. • Open and inspect nest boxes before removing them from the enclosure. Some species will use these boxes as hides and may be found clinging to the lid or buried in the substrate. • Transfer hatchlings in a safety tub. When moving or cleaning enclosures housing very small hatchlings place the container inside another container before opening the lid. When a tiny baby escapes there is considerable reluctance to lunge out and grab it for fear of injuring it. This slight hesitation is usually sufficient time for the hatchling to escape. If it escapes into a larger container, you have a second chance. • Prevent live food from escaping the enclosure. If it can escape, you potentially have a hole sufficient in size for an occupant to escape. • Beware of vermin attempting to get into an enclosure. Vermin may chew through flywire or shade cloth of mesh terrariums to mutilate sleeping reptiles and create escape holes for surviving specimens.

QUARANTINE   In order to prevent the introduction of diseases to your collection it is generally recommended that new arrivals be subjected to some form of quarantine procedure. This is designed to reduce the introduction of bacterial, parasitic and viral diseases to your collection. The latter is not a significant issue with geckos or pygopods. With regards to captive bred hatchlings, minimal quarantine is generally required as they are unlikely to have been exposed to any quantity of pathogens, as they are usually housed separately or with their siblings only. With regards to adults, the predominant issue to consider is that of internal and external parasites. A faecal examination will identify and lead to the appropriate treatment of internal parasites. Parasitic red mites may be observed in the eye sockets, armpits and lower neck of geckos. Pygopods must have their scales closely examined for snake mites Ophionyssus species— these may cause scales to lift slightly and mite faeces will appear as white flecks on the scale surface. If parasites are identified then treatment should be administered as outlined in Parasitic Disorders—External Parasites on page 121. For individuals with no apparent parasitic issues, a period of 4–6 weeks in isolated housing should be enough time to identify any potential issues before housing in the main collection. page 33

HOUSING The diversity of gecko and pygopod species available for captive care may be accommodated simply in just a few basic types of enclosures. Consideration must be given to each genus and species as well as an individual’s requirements for heating, lighting, security, substrate, ventilation, humidity and furnishings. However, this does not mean that housing geckos or pygopods needs to be complicated or expensive.

The predominant means of housing geckos and pygopods is in indoor enclosures. Consider the specimen’s basic requirements as well as your own preferences in design when investigating enclosures. Following are the various types of indoor enclosures available.

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INDOOR ENCLOSURES

Rack Systems

Tubs Essentially the same as rack systems, tubs are generally positioned in a more open manner, allowing heating and lighting to be provided from above. They are inexpensive and available in a range of sizes. Tubs are suitable for many terrestrial species of geckos and most pygopods. The main disadvantages of tubs are the limitations on furnishings, their aesthetic appearance and their poor security—it is difficult to supply appropriate heating and lighting with a lid on the container. Access can be improved by placing the tub on shelves that can be attached to drawer sliders allowing the whole tub to be moved out from beneath heating and lighting fixtures. Recycling tubs are positioned on sliding shelves for easy access

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Rack systems comprise plastic tubs enclosed within a shelving system and are commonly used for housing terrestrial geckos. They are compact, secure and inexpensive. The major disadvantages of rack systems are they are not as aesthetically appealing as other types of enclosures and are difficult to light appropriately. Heating is usually limited to subfloor heating. This dramatically limits their suitability for terrestrial species that are unable to climb, particularly burrowing species. They are generally unsuitable for pygopods or arboreal geckos as they often have Rack system suitable for knob-tailed and thicksmall gaps and crevices. tailed geckos

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Tanks A basic fish tank has a plethora of uses for a lizard keeper. As with tubs and racks, tanks are compact, inexpensive and available in a range of sizes. Be aware that large tanks are often higher than they are wide and, while suitable for fish, are cumbersome when housing some lizard species. Tanks have many advantages including their aesthetic value—keepers can easily observe their pet. They can be made secure through the use of commercial or homemade lids or by simply matching the tank size to the physical abilities of the individual species—a 60cm high tank is suitable for a 30cm pygopod without the need for a lid, provided furnishings are not high. Heating and lighting can be supplied using fittings mounted within the tank or on top of the tank lid. Custom-built tanks allow for a greater number of housing options. Cheap plastic tanks are robust enough to house most gecko species. Plastic aquariums used to accommodate small geckos in a rack system

These python-style enclosures feature five solid sides and a glass or mesh front. Timber enclosures are secure, accessible, aesthetically pleasing, easy to supply light and heat to and may be purchased commercially or be homemade. They are suitable for accommodating terrestrial and arboreal species, depending on furniture placement. Their suitability as arboreal enclosures can be improved by decorating the rear and side walls with mock rock or by firmly attached furnishings. The main disadvantages of timber enclosures are they are expensive, difficult to ventilate, prone to overheating, heavy and are generally only suitable for dry furnishings—sealed timber and melamine will eventually succumb to water Custom made timber enclosures suitable for housing geckos and pygopods damage.

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Timber Enclosures

Glass, Perspex, or Plastic Moulded Commercial Terrariums Increasing in popularity and availability, these enclosures feature three to four solid sides and one to two mesh sides—or two sides made of half mesh—and a glass front door. Glass terrariums are secure—few adult geckos or larger pygopods have narrow enough heads to escape from standard glass doors or narrow gaps—they are durable, available in standard sizes allowing for standard shelving, and are easily made aesthetically appealing—some include mock rock backgrounds as a standard fitting. page 35

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Commercial glass enclosures are suitable for most gecko species

These Exo TerraTM commercial glass terrariums house geckos and pygopods in the author’s collection

The main disadvantages of glass terrariums are their fragility, expense, weight considerations Moulded plastic terrariums (with modified wire and they rarely include fitted heating and fronts) used for large gecko species in the author’s lighting—the keeper must usually provide collection these. Sliding glass doors are commonly used on plastic moulded terrariums and can be a security risk where the glass panels overlap—particularly for geckos and Delma species. When using moulded plastic enclosures it is recommended to replace the glass front with metal framed mesh fronts to improve ventilation and avoid overheating. page 36

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Mesh Terrariums Mesh terrariums are constructed using plastic or metal frames with either mesh inserts or a mesh bag zipped over the structure. They are water resistant, lightweight, well ventilated and more affordable than similar sized glass or timber enclosures. The major disadvantages of mesh terrariums are they are difficult to heat due to excessive ventilation and the risk of melting the mesh and framing. They are also prone to damage by mice. They are suitable for arboreal geckos, most species of pygopod and heat sensitive arboreal species such leaftail geckos. D BROWN

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A commercial mesh terrarium—InstacageTM

A commercial mesh terrarium with sliding doors— Exo TerraTM

HaileaTM hexagonal mesh terrariums housing Strophurus geckos

OUTDOOR ENCLOSURES Outdoor facilities are ideal for housing large species and for taking advantage of local climatic conditions. However, they are of limited benefit to geckos and pygopods due to their habitat preferences. In outdoor enclosures, burrowing, cryptic and nocturnal species will rarely be observed unless their enclosures are near a window. However, some breeders have experienced their best results when their geckos and pygopods were housed in natural enclosures. The primary limitation on outdoor housing is your local climate—if it is permanently cold and wet, outdoor enclosures are only suitable for native species that have adapted to these conditions. In more temperate regions, more species may be maintained outdoors, however the species’ original climate must be considered in relation to the local temperature, humidity variations and rainfall—for example, a species originating from central Australia may adapt to temperatures in central Queensland but may not tolerate sustained periods of rainfall. page 37

Similarly, a species from southern Victoria may find rainfall and winter temperatures acceptable but may not cope in the hot summer climate. In general, species most suited to outdoor enclosures are those with a wide, natural distribution as this indicates their adaptability. There are two main types of outdoor housing—pits and aviaries.

Pits

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Pits are generally fixed to the ground and may be constructed as a series of walls around an appropriate area of ground or from a pre-existing structure such as an apple crate, bathtub, spa bath or stock trough. They have been used to house ground-dwelling gecko species but the cryptic nature of these species makes it a somewhat boring housing option. These fully enclosed outdoor structures may be an extension to a pit, a commercial or purpose-built bird aviary or a suspended wire aviary. This may be useful when planted enclosures are used to house arboreal geckos or large pygopods—these species require 6mm x 6mm mesh for security. Flyscreen or shade cloth is suitable for smaller pygopods. The size of the mesh selected directly influences the amount of UV-B light able to penetrate the enclosure—for example, 6mm x 6mm mesh will block up to 20% of UV-B rays and flyscreen or shade cloth will block 30–50%. For this reason, larger mesh is more suitable on the roof than on the walls. UV-B penetration can also be hindered by reflectance from the wire. Painting the outside of the mesh with non-toxic matt black paint may reduce this reflectance. Wire of 6mm x 6mm

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Painting the outside of the wire mesh in black paint improves visibility and also improves UV light penetration by reducing reflection

Aviaries

A suspended floor enclosure used for housing large pygopods

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dimensions, and painted in black, blocks 10% less UV-B than unpainted wire in full sunlight. This will matter to pygopods that may bask, but will have limited impact among most gecko species. A suspended wire floor covered in leaf litter has been found to be useful in areas of high rainfall, as it allows free drainage.

ENCLOSURE SIZE Enclosure dimensions are one of the most hotly debated topics in herpetology and can be particularly confusing for new keepers. It is hard to generalise as the needs of each species—and often each individual within that species—varies. Factors that influence enclosure size include the type of species to be accommodated, the occupant’s temperament, sex and reproductive state, the type of furnishings, the number of lizards being accommodated—some species require greater than twice the space when two are housed together—and the keeper’s ideals. The recommendations provided throughout this book are based on SVL—the snout-vent length. This is the distance from the tip of the snout to the opening of the cloaca (vent). By using this measurement as a guide, enclosure sizes can be modified as the occupant increases in size. The sizes recommended are a minimum for a pair. Although a bigger enclosure is better for many species, this is not always the case—some species and age classes feel more secure in smaller enclosures—hatchlings prefer smaller enclosures for the first six months. Recommendations on enclosure size are dynamic and some keepers may find my suggestions too small, whereas others may consider them large. Whatever size you choose, being able to maintain specimens over a long period of time with few aggression problems, while also experiencing breeding success, is the best indicator of a suitable enclosure.

Minimum Enclosure Sizes Minimum Enclosure Length (SVL)

Minimum Enclosure Width (SVL)

Minimum Enclosure Height (SVL/VL)

Velvet Geckos Oedura/ Amalosia/ Hesperoedura/ Nebulifera spp.

3−5

3−5

3−5

Knob-tailed Geckos Nephrurus spp.

4−5

3−4

3−3

3

3

2−3

Small Arboreal Geckos Strophurus, Crenadactylus spp.

5−7

5−7

6−10

Cave Geckos Pseudothecadactylus spp.

4−6

4−6

4−6

Small Terrestrial Geckos Diplodactylus, Lucasium, Rhynchoedura spp.

4−5

4−5

2−5

Dtellas/House Geckos Gehyra, Hemidactylus, Christinus spp.

3

3

3−5

Bynoe’s/Desert Cave Gecko Heteronotia spp.

4−6

4−6

2−3

Ring-tailed Gecko  Cyrtodactylus spp.

4−6

3−4

3−5

Leaf-tailed Geckos Phyllurus, Saltuarius spp.

4−6

4−6

4−6

Pygopods Delma, Pygopus, Lialis, Paradelma spp.

3−6

3−6

3−5

SPECIES/GROUP

Thick-tailed Geckos Underwoodisaurus/ Uvidicolus spp.

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COMPATIBILITY There is a tendency among some keepers, particularly newcomers, to want to house groups of geckos and pygopods together, often of varying species. However, lizards are generally not accommodating when it concerns compatibility. Problems may be experienced— Between individuals of the same sex. Males should generally be kept as one per enclosure, although some species may tolerate other males in the absence of females. Between males and females. Some species are solitary and will only associate with each other in the breeding season—beyond this they avoid contact. However, some keepers insist on housing them as pairs throughout the year. Between individuals of varying ages. Adults of most species are generally intolerant of juveniles and may consider them prey. Some species may form strong family bonds and actively protect their offspring. Between individuals of different species within the same genus. Despite being similar in needs, most closely related species see each other as competitors and interact negatively. On the occasions that they do not, they risk hybridisation. Between individuals of different species within the same group. Most interactions between varying species of the same group—such as gecko versus gecko— are based around competition between resources and territories. In 90% of cases, unless there is considerable separation of niches—such as one arboreal species and one burrowing species— community groups are incompatible. Between individuals of different species of different groups. Mixing individuals from different groups—such as geckos with skinks—usually ends in disaster. This is often due to a predatory problem, although it can be territorial. Seemingly mild mannered species will often unpredictably injure or consume a cage mate. There are some combinations that work well, but this is usually when a smaller aggressive species is maintained with a larger more passive species. Between individuals of varying taxa. Attempts are occasionally made to maintain lizards in enclosures with other animals, such as birds. There is the odd occasion when this works out for both animals, but usually lizards end up feeding on some part of the other animal’s lifecycle—such as eggs, hatchlings or fledglings—or they may cause the animal distress. Compatibility between and within species is explained in more detail in the specific species chapters. However, it is best not to experiment with compatibility unless you are willing to suffer losses.

VENTILATION Most keepers are more concerned with maintaining adequate heat levels in their enclosures and may give less thought to the issues of poor airflow and overheating. When hot air rises in an enclosed space, it can only rise so high before it runs out of space. This results in the entire enclosed area heating up and the loss of all heat gradients. Occupants are forced to endure one stable temperature throughout the day, which may not be the appropriate temperature. During summer, ambient temperatures outside of an enclosure will rise, making it impossible to maintain heat gradients and easy to overheat an enclosure. However, appropriately positioned ventilation can ensure some air movement. page 40

Ventilation should ideally consist of two sets of air vents. The first set of vents should be placed low and at the front of the enclosure in an unobstructed area with free access to the open air. The second set of vents should be placed high and towards the back of the enclosure to allow heated air to escape. This will, in turn, draw cooler air in through the vents at the front of the enclosure. When providing ventilation, consider the effect it has on humidity. The greater the ventilation, the harder it is to maintain high humidity environments and vice versa. Therefore, if you are attempting to maintain a high humidity in the enclosure and have plenty of ventilation, you may need to add more moisture—this is not necessarily bad, as insufficient ventilation in an enclosed, moist area will lead to fungal build-up. In an environment designed to be of low humidity, insufficient ventilation will allow humid air to be retained, while good ventilation will allow humid air to be replaced with drier air from outside. There is some merit in designing enclosures with adjustable ventilation so that vents may be closed or opened depending on the climatic conditions. In a dry enclosure, vents may be closed on rainy days when humidity is high to restrict the flow of humid air into the enclosure or they may be opened to allow additional airflow into a rainforest style enclosure on a similar day. There is considerable variation in the quality and long term stability of vents. Most vents are plastic and designed for indoor use and, therefore, may not tolerate exposure to high temperatures or UV light. They often become brittle when used in gecko and pygopod enclosures and may break due to expansion and contraction as the enclosure heats and cools. They are not usually a problem in snake enclosures due to the lower temperatures and lack of UV light. I recommend installing metal vents or heavy duty plastic vents designed for outdoor use. Good quality ventilation is available from boat equipment suppliers and is generally robust and able to cope with UV exposure. Alternatively, stainless steel sink strainers make great air vents—they are readily available, strong, inexpensive and aesthetically pleasing when fitted and may be drilled and screwed.

SUBSTRATE Substrate is the surface on which an animal lives. The choice of substrate in a reptile enclosure is a subject of much debate. Many recommendations regarding enclosure substrates are based on their suitability for one or two species of gecko or pygopod, which may not be applicable to Australian species. There is no ideal substrate for any one species and each keeper needs to weigh up the positives and negatives of each type of substrate available. There are some substrates that are disgraceful and should never be used. Following are the most readily available substrate types and their pros and cons.

Sand Sand is the most hotly debated substrate worldwide due to its potential ability to cause gut impactions. This is a significant risk to some species and occurs when sand is ingested inadvertently while eating, usually because it has become stuck to moist food or because the gecko or pygopod has grabbed a mouthful when lunging for a food item. It may also be ingested if the gecko or pygopod tastes the substrate and it becomes stuck to the tongue. Although gut impaction from sand is a concern, it is far less of a problem among Australian species—possibly because many local species live entirely on sand and that the sands available for use as substrate in Australia are similar to those found in the wild. The only class of gecko and pygopod that I routinely avoid the use of sand with is juveniles— except for Nephrurus, Diplodactylus and Lucasium geckos. Juveniles, measuring up to 50% of adult SVL, have small digestive tracts and require less sand to ultimately cause impactions. page 41

There are sand products available that claim to be safe and provide a calcium supplement— these are misleading. Any reptile eating a sufficient amount of this sand to be able to utilise it as a supplement will soon die from the impaction it has caused. Another infrequent issue associated with the use of sand as a substrate is cloacal irritation. This occurs when sand sticks to everted cloacal tissue or the hemipenes during defecation and mating. When these mucous membranes are drawn back into the body, the sand comes with them, causing irritation and infection in some species. Again, cloacal irritation is not common and that may be because many Australian species have adapted to defecate and mate on the sand and have developed methods to deal with inadvertent sand pickup. I use sand in enclosures housing virtually all arid or semi-arid species and for most nonrainforest arboreal species. The type of sand used in an enclosure is very important. Sands with fine, smooth grains are recommended. Red desert sands are ideal but may be difficult to obtain without some effort and cost. Washed beach sand is a good choice—think of it as uncoloured desert sand. Playground sand, often known as washed pit sand, is also suitable. Sand with large grains, such as coarse river sand, or a clay component, such as brickies loam, should be avoided. A deep layer of sand will encourage natural burrowing behaviour among many species. With arboreal species, a thin layer of sand 10–15mm deep is recommended to prevent faeces from sticking to the enclosure floor. Generally, sand is sanitary as long as faeces are not allowed to build up. Sand can be cleaned in various ways including through a mesh colander, sieve or a soft aquarium net or by washing. It can be resterilised using dry heat in an oven, wet heat—which uses steam to sterilise it—or it may be disinfected and allowed to dry naturally in the sun. Over time it is easier to replace sand than it is to recycle it. Although sand has its risks, it will always remain my preferred substrate for the classes of animals listed earlier.

Soil Soil is really just glorified sand (aka dirt)—except it is dug fresh from the garden or from a block of land. Within dirt you will find sand, organic material, bacterial and fungal organisms, chemical residues, insects and earthworms—these may sound natural, but are best avoided. Once soil becomes moist and contaminated with faeces it is unhealthy. Pre-existing soil in outdoor enclosures is best covered with a more appropriate material.

Gravel This substrate material is similar to large grains of sand. Depending on its grain size, gravel will be either more likely to cause gut impaction than sand, or be too large for a gecko or pygopod to swallow. It is best used in association with water, as either a substrate providing drainage below the contact substrate or as a secondary substrate around water bodies to reduce muddying of water. It is not entirely suitable for geckos and pygopods, unless needed in planted enclosures.

Scoria This volcanic rock substrate, also known as Quincan, is an attractive landscaping feature used in most gardens. Very large pieces may be used as basking rocks. However, care must be taken when using these rocks, as some pieces may emit fumes when heated, possibly containing sulphur. Small pieces of scoria should not be used as flooring substrate—they are rather abrasive.

Leaf Litter This attractive substrate material should only be used as a deep primary medium, or when mixed page 42

with potting mix, in rainforest style enclosures. Leaf litter is difficult to clean and may sour if allowed to sit in a layer of water. It is best laid on a bed of gravel. Leaf litter can be useful when placed as a thin surface layer in enclosures accommodating small pygopods. Its main disadvantage is that it makes live food harder to catch as food items can hide readily. However, it is easily replaced and usually free. It can be frozen upon collection to eliminate unwanted insect and arachnid pests. I am not aware of any cases of impaction from leaf litter.

Potting Mix This substrate material is a blend of sand, composted bark fines and sawdust. It is suited to rainforest style enclosures where it is used as the main substrate or mixed with leaf litter. It is easily maintained as a moist, friable substrate, suitable for plant growth. The main disadvantages of potting mix are that it is laden with micro-organisms, can become mouldy and is difficult to clean. However, it is inexpensive to replace. If potting mix is your desired substrate, try to use a product free from fertilisers, herbicides, water crystals, vermiculite and perlite—these all pose ingestion risks and should be avoided. Potting mix may also be used over a gravel base (allowing drainage) in an enclosure housing geckos such as Saltuarius and Phyllurus species.

Sphagnum Moss This plant material can hold a large amount of water and is primarily used to retain pockets of moisture within an enclosure. It may also be used to create a high humidity microenvironment within the layer, to humidify an entire enclosure or as an egg laying medium. It is suitable for use within the substrate—either in a mound in one corner or as a layer on the top to restrict access to other substrates. It can be removed for periodic cleaning in warm water and then sterilised with steam or baked at 120°C for one hour. Sphagnum moss is best suited to rainforest or wetland style enclosures and for use as an egg laying medium with leaftail geckos Saltuarius and Phyllurus species.

Peat This substrate material may be purchased as true peat, which is decomposed sphagnum moss, or as coir peat, which is a finely chopped by-product of the coconut industry. Although true peat has superior water holding properties, coir peat is adequate for most reptile enclosures. As a substrate on its own, coir peat may become dusty if allowed to dry—it will then adhere to everything and pose an impaction risk. I prefer to use it as a component in other substrates to improve water retention. When mixed with sand, coir peat improves friability and drainage. It is an ideal egg laying medium for most species when mixed with sand in a ratio of 1:1. It can also be used as moist substrate for hatchlings, particularly Saltuarius, Phyllurus and Thick-tailed Geckos Underwoodisaurus/Uvidicolus species.

Bark and Wood Chip This substrate material is not recommended for use. Very few gecko or pygopod species naturally choose to dwell in chopped up timber or bark. Although they may be aesthetically appealing, these bark and wood chips are predominantly made from pine and exude large amounts of volatile fumes that can irritate a specimen’s respiratory system and can pose a significant impaction risk if small pieces are swallowed. Some companies bag and market bark and wood chips for reptile use—most are unsuitable. Products based on cypress mulch are considered acceptable. Bark and wood chips are impossible to clean and should be removed as soon as they are soiled. page 43

Wood Shavings There has been a recent trend to use aspen shavings as substrate in reptile enclosures. Aspen differs from regular shavings in that it does not exude volatile fumes. There are two types— shavings and fine chips. The latter is designed primarily as bedding for small rodents and should not be used in reptile enclosures. The major disadvantage of aspen shavings is that they cannot be cleaned and must be replaced with fresh shavings when they become soiled. They should be removed and replaced at least once a month. As with all timber products, shavings are indigestible and may cause impaction. Therefore, feeding should be carried out using wide, raised dishes to avoid shavings becoming stuck to food items.

Corn Cob Litter This substrate material is a crumbled litter derived from dried corn cobs. Although it is highly absorbent, it will spoil when wet, becoming a hive of bacterial and fungal organisms. It is indigestible, highly prone to causing impaction and may irritate the lips of geckos and pygpods that chew it. It has also been known to kill reptiles by means of inhalation and suffocation.

Walnut Shell Litter As with corn cob litter, this substrate material is highly prone to causing impaction and will spoil when wet or when contaminated with faeces and food remnants. It differs from corn cob litter in that it is non-absorbent and possesses sharp particulate components that are abrasive and uncomfortable on reptiles’ feet. It should be avoided.

Alfalfa/Lucerne Pellets These pellets are often sold as cat litter and rodent or horse food. They are the least problematic of all types of pelleted materials, as they are fully digestible if consumed by accident. Their major disadvantages are that they become mouldy and decompose fast with very little moisture. If used, they must be replaced regularly and kept dry at all times.

Compressed Timber Pellets These pellets are sold for use as cat litter. They should be avoided as they emit strong, volatile gasses, are indigestible and prone to causing impaction.

Compressed Newspaper Pellets This substrate material is sold as cat litter and is widely used by some and maligned by others. The major disadvantages of compressed newspaper pellets are that they are dusty, prone to causing impaction and may cause cloacal irritation if they become stuck to everted hemipenes. They also become mouldy and unhygienic when moist. Despite this, some keepers recommend this substrate as a floor covering.

Zeolite and Clumping Cat Litter These products are suitable for cat litter but should never be used for reptile substrate. They cause impactions if consumed and are abrasive on feet and the ventral abdominal skin.

Paper Plain newspaper or butcher's paper has been used as a substrate for snakes for many years and has many followers in the lizard fraternity. It is easily accessible, inexpensive and absorbent and page 44

suitable for lizard enclosures if it is clean. Printed newspaper should be avoided due to the risk of ink toxicity and staining to the skin.

Artificial Grass This commonly used substrate has several useful features. The less expensive brands of artificial turf are preferable—they are more flexible and less abrasive than stiffer and denser products. The edges should either be heat sealed or oversewed to prevent loose threads entangling occupants. Several pieces should be available so that one can be used while the remainder are washed and dried. It should be replaced when it becomes worn or when small pieces begin to flake off. Artificial grass provides suitable grip for most species and is sufficiently comfortable on lizards’ feet. The main disadvantage is that live foods, such as cockroaches, will often congregate underneath.

Indoor/Outdoor Carpet Carpets are similar to artificial turf but harder to clean. The glues used to make them often emit fumes. Therefore, when new, they should be aired for several days before use. Some types may be water repellent, causing faeces and urine to sit on top rather than be absorbed. Carpets are generally inferior to artificial turf.

HIDE SITES Many gecko and pygopod species spend their inactive time out of sight—sitting in the open is unsafe. In the wild, reptiles seek out spaces in hollows, burrows, cavities under rocks or logs, grass clumps and flaking bark to hide. If required to rest in the open, geckos and pygopods may utilise cryptic colouration to disguise themselves. In captivity, inactive lizards must be supplied with a hide area they can secrete themselves away in and feel secure. An animal without a hide is in constant fear of predation, whereas a secure animal is more likely to breed—its mental health has been catered for along with its physical health. When considering suitable hide areas for captive species, consider those found in the wild. There is little benefit in providing ground level hide areas for arboreal species or vertical hides for ground dwellers. Housing factors such as substrate or the style of housing may determine the design of a hide—burrowing species on deep sand substrate may need no additional hides as they will essentially make their own. If the substrate is shallower, a hide or burrow may be required to make the occupant feel as if it has burrowed. Hide sites may be limited both by substrate depth and available floor space in enclosures such as tubs in rack systems. There are two main types of hide sites—vertical and horizontal.

Vertical Hide Sites Most gecko species that utilise vertical habitats will hide in nest boxes, overlapping boards, vertical containers, bark slabs, cork rolls or hollow logs—although these are hard to extract occupants from. I recommend providing small rectangular plastic tubs or round pot plants— the supplied bases of these pots can be used as lids and an entrance hole up to 1.5 times the width of the animal at its widest point, can be cut into the top. Transparent plastic tubs may be rendered opaque by painting them. The hide must be a snug fit of approximately 2 SVL long x 1 head height wide. Although individuals may avoid excessively large hide sites, a group will use such a site. page 45

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Bark slabs

Plant pots make ideal vertical hide sites

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Nest boxes may be more effective as hides when filled with substrate or loosely filled with dry or moist sphagnum moss, pieces of paper bark, folded paper towel or small pieces of bark. The substrate should provide an open space of 1.5−2 SVL long x 0.5 SVL wide. In small enclosures, arboreal species will use hides wherever they are located. In larger enclosures that measure more than 5 SVL high, elevated hides are preferred. Geckos and pygopods will tuck themselves against an edge in a corner when resting in boxes. This can be an effective way of localising resting areas into one space, allowing for the remainder of the enclosure to be more effectively furnished.

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Terracotta saucers and bamboo splits make ideal hides for small species

Horizontal Hide Sites Species that prefer horizontal hide sites can be provided with boxes, intact hollow logs, hollow logs split in half lengthways, inverted terracotta or plastic pot plant saucers, bamboo pieces split lengthwise, terracotta tiles, tile or timber stacks or commercial hide sites usually shaped as artificial rocks. Horizontal hides can be used in one of two ways. Most burrowing and digging species will use a hide as a starting point for their burrows, which may start as a shallow depression. Other ground dwelling species will use hides as pre-existing cavities—the artificial equivalent of soil cracks, gaps under logs and spaces between rocks. When determining the placement of hides, consider the relevant safety issues. Plastic hides are at risk of outgassing—which is the production of fumes from heated plastic—and must never be placed directly under a heat source. Timber hides should also be placed carefully to ensure they do not pose a fire risk if exposed to excessive heat. Commercial hide structures

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Terracotta pot saucers have innumerable purposes for the reptile keeper. The most important is a conveniently sized hide. Doors can be provided by making two parallel cuts in the pot edge, using a grinder fitted with a masonry blade. The centre section is then tapped out gently with a hammer. If the saucer is to be used as a basking site, it is essential to make two doors to allow for ventilation and to provide an alternate exit should one become accidentally blocked. Commercial hide sites are available in a range of designs and sizes and most are adequate. My only complaint about these hides is that the outside finish is often much better than the inside surface. Internal sharp edges may need to be ground down with a Dremel® tool or engraver before use. Magnetic hides, where the occupants can be observed by removing a magnetically attached panel on the exterior of the tank, are well tolerated. However, if they are not firmly attached internally they can easily trap an individual’s toes between the glass and the hide when the cover is replaced and the inner part shifts slightly.

ENCLOSURE ENRICHMENT Part of the joy of keeping reptiles is observing as they interact with their environment and exhibit natural behaviours such as burrowing, using dominant display perches, displaying food ambush postures and establishing and reinforcing territories. These behaviours bring out the best in some species as it allows them to appear as they would in the wild. It also encourages keeper satisfaction, which is essential for longevity in this hobby—once the profit that many seek runs out, enjoyment is all that remains. There are a number of methods for improving the aesthetic appearance of an enclosure and its useability for occupants—a keeper must refrain from overdecorating and creating a habitat that is cumbersome to negotiate and difficult to clean. When deciding on appropriate furnishings consider the natural and microenvironments the species in your care uses in the wild. I have observed many overseas collections of arid and semiarid species held in heavily planted tropical enclosures because the keeper incorrectly believed that all of Australia was moist and tropical. To determine your specimen’s natural environment, consult a field guide and observe the background in which it is photographed. Refer to the front of the book where most good field guides include an often overlooked section on Australian habitats, designed to give those who have never been here, a snapshot of that species’ world. Study the information regarding its habitat and microhabitat and try to mimic this in your enclosure.

Surface Litter Regardless of the primary substrate being used, most pygopods feel more at home with a layer of surface litter placed over the top. For other species, leaf litter makes the enclosure more interesting. Before surface litter can be included in an enclosure, there are a number of considerations. Excessive litter may make it difficult for an occupant to find its food. Although this challenge may be a form of behavioural enrichment, it may also lessen the food that can be consumed in a single sitting. The introduction of insects, particularly ants, and arachnids, such as spiders and mites, are always a concern in leaf litter—particularly when rainforest litter is introduced. Life forms within the litter can be killed by deep freezing the litter for two to three days before use.

Branches and Hollows A gecko or pygopod climbing on a piece of timber dowelling is disappointing to observe when there are so many natural branches around—these provide a better range of surfaces for a lizard to grip. page 47

Natural branches can be selected according to the perch or basking requirements of a particular species. Many species, including Spiny-tailed Geckos Strophrurus, require narrow branches. A reasonable guideline when selecting natural branches is for a branch to measure two-thirds of the width or the same width of the occupant’s head. Alternatively, study photographs in field guides to observe what branches the gecko or pygopod has naturally chosen—assuming the photograph has not been posed. A great place to obtain a large amount of branches is the green waste area at your local tip or on the roadside after a heavy storm. This is preferable to collecting branches from the bush, which may already be serving as habitat for wild species. Branches from Australian native plants are preferable—avoid branches with thorns or bristles on the bark. As with leaf litter, branches may be placed in the freezer to avoid the introduction of pests— however, I have never felt the need to do this unless a log has a small ant colony within it.

Artificial Plants Although geckos and pygopods gain little pleasure from artificial plants, they may be considered for a naturalised enclosure because they provide valuable hide sites and brighten the space. However, it can be difficult to match artificial plants to a species—most artificial plant manufacturers do not produce arid zone plants in their production catalogues—a shame because many Australian lizard species are arid or semi-arid. The selection of grasses is also disappointing unless you have a wetland enclosure, for which there are a plethora of reeds available. It is often easier to purchase artificial plants online, rather than search for a single store that has everything. Generally, it is recommended to avoid including plants with wide, flat leaves—they will become a depositing site for faeces and can be hard to clean. In enclosures with shallow substrate, upright plants may be anchored to a 5–10cm nail or screw placed through the base of a 10–15cm square piece of plywood or flat plastic plate buried beneath the substrate to anchor it. This will provide stability and allow the whole unit to be removed for cleaning.

Dried Plants In some enclosures when artificial plants will not work well or are not commercially available, dried plants may be suitable. The most common dried plant that I use are grass clumps, which can be provided as desert décor or as climbing and hide sites for small semi-arboreal Paradelma and Delma and grass dwelling geckos. A small grass clump laid horizontally is an ideal hide site for small terrestrial geckos, which will often use it when ambushing food items. Not all species of grass are suitable. Grasses should be avoided if they are very fleshy or possess fine surface bristles and broad leaves. Most native grasses or grass-like plants are ideal—Poa, Conostylis, Pennisetum, Themeda, Triodia, Stipa, Dianella, Xanthorrhoea and foreign grasses such as Buffel grass (Cenchrus spp.) are just as suitable. Grasses can be used in entire clumps dug up with their roots or as tops that must be bound appropriately. When using entire clumps, preparation is required to produce a quality end product—except with Spinifex grass Triodia species, which never fails. To prepare the grass, take the freshly dug or pulled clump and shake all of the soil out of the root ball before trimming the straggly roots to a nice clump. Hang the clump upside down in a sunny, dry area, such as from a clothesline—it should be left there until the green begins to fade from the leaves, which are unlikely to wilt at this stage. Depending on the species of grass, this step may take two to 10 days. Once the clump is dry, either ‘replant’ it in the substrate or anchor it to a board as described for artificial plants. page 48

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If only the tops are collected—as when using Xanthorrhoea leaves—or if the grass clumps are very sparse, they must be bundled together before drying. To prepare the grass, gather up an appropriate amount for the end product and tie three ziplock or cable ties around the base of the bundle, approximately 10mm apart. The entire base is then trimmed approximately 10mm below the bottom cable tie. Hang the bundle using the same method described for hanging complete clumps. When dry, the partial clumps can be buried in the substrate and A selection of artificial plants positioned between solid objects to prevent them from falling over. Alternatively, they may be anchored to a board or plate or be provided with support legs made from three to four pieces of ‘L’ shaped heavy fencing wire pushed up through the bottom centre of the clump. Other dried plants that are suitable for use in enclosures include arid zone daisies such as Helichrysum, Bracteantha, Rodanthe and Chrysocephalum and upright shrub species such as Banksia and some Grevillea, which dry well with minimal leaf loss. To identify which species do not drop their leaves after death, observe dead plants in gardens, burnt areas or areas where weeds have been sprayed. A selection of dried plants Drying methods for these plants are much the same. Once the plants are dry, their longterm stability can be improved by spraying or dunking them in a diluted mix of PVA glue and water to stiffen and seal them.

Live Plants Live plants are suitable for species maintained outdoors or indoors in moist enclosures with deep substrates depending on the type of enclosure. Plants in heated indoor enclosures will require regular watering, which will create a high humidity—such an environment is only for suitable rainforest or wetland species such as Leaf-tailed Geckos Salebrosus, Ringtailed Geckos Cyrtodactylus and some Delma species. Support structures for dried plants

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A simple arrangement of dried plants can brighten up the most boring of enclosures

Suitable plants for indoor use include small grasses, ferns and climbers. Live plants will require a form of full spectrum lighting to encourage their growth and survival. In outdoor facilities, the only limitation on plant selection is the local climate and the degree of shade that will be produced by the plants selected. For non-destructive species, many low perennial natives are ideal and are virtually guaranteed to be non-toxic. Exotic plants may also be used.

HEATING The simple act of being a reptile makes heating the most important aspect of reptile keeping. ‘You are what you heat’ is the motto by which most reptiles survive. Understandably, getting the heating right for each individual species can be a challenge considering we may keep species that originated in hot deserts, cool rainforests and alpine meadows in the one room. Getting heating A gecko enclosure decorated with wrong is literally a matter of life and death. artificial plants In addition to providing appropriate temperatures for basking, keepers must also provide a temperature gradient. This is a gradual change in temperature from one end of the enclosure to the other, and provides occupants with a variety of temperatures in which to reside. Provision of a lower temperature is recommended at night to mimic the natural drop in temperature at this time. There are numerous products available for heating reptile enclosures, as discussed below.

HEAT CORD OR TAPE This type of resistance heater creates frictional electrical heat when a current is passed through coiled or highly resistant wiring circuits. These circuits either heat up to a maximum temperature for that wattage of cord or heat up to a specified degree above the ambient temperature— page 50

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Heat cord

Heat cord may be recessed in a routed groove. Aluminium tape will improve heat dispersal

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self-regulating heat tape usually heats by 10oC−15°C above the ambient temperature. It is used largely in the refrigeration industry to prevent refrigeration drainage channels from icing up and is generally water resistant and safe. Reptile specific heat cord or tape is available in various wattages—the length of the resistance cord determines the wattage. Heat cord or tape is most suitable for species that obtain warmth from heated surfaces such as rocks or low intensity basking sites. It is a useful heating source with terrestrial and arboreal geckos and small pygopods that inhabit dense vegetation and only bask in small flickers of sunlight that penetrate the branches. Heat cord or tape is best used as an underfloor or surface heater and is generally quite safe unless an excessive wattage cord is allowed to overheat the structure that sits on it, causing tubs to melt or glass to crack. It should be used in combination with a dimming or pulse proportional thermostat. Incorporating heat cord into a rack system can be achieved by cutting a small groove into the shelving with a router and recessing the cord into the groove. A strip of aluminium tape may be stuck over the recessed cord to protect it and to provide a heat absorbing cover that spreads the heat over a wider area.

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This heating product is constructed from flat sheets of very narrow heating elements A plastic coated heat mat embedded in a thin plastic sleeve. It produces heat by emitting infrared waves directly upwards to a distance of a few centimetres. Heat mats are suitable for heating the sides of glass enclosures, for use beneath rack systems or below individual tanks or tubs. They are generally placed beneath a structure or against a wall and, although they will not heat the air, they will heat objects directly on top of the mat. A selection of heat mats

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Heat mats are prone to overheating and must be used in combination with a dimming or pulse proportional thermostat. If they are creased, folded or bent in any way, the damaged area often acts as a focus for uneven heating and may lead to malfunctions or sudden extreme heating that could melt any containers resting above. Heat mats provide higher degrees of heat than heat cords. Their use is best restricted to heating the sides of glass enclosures to provide heated surfaces for arboreal geckos or for use under rack systems or individual tanks and tubs.

HEAT ROCKS These artificial rocks are constructed from cement based products or resin and are heated by resistance cords located within. They are suitable for use only as supplementary basking heat for nocturnal species, as they do not provide enclosure heat or act as a primary heat source. Newer models contain internal thermostats—a dramatic improvement from the notoriously unreliable older units. The major disadvantage of heat rocks is that when they malfunction they become superheated and may burn a gecko or pygopod that comes in contact with them. There is also no visible way to tell if a heat rock has malfunctioned, so they must be checked regularly.

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A heat rock with thermostat

CERAMIC HEATERS

Ceramic light bulbs provide no visible light but emit high intensity infrared heat waves. They are generally used in combination with another source of visible light to provide high basking temperatures or heat when visible light is not needed—such as at night. Ceramic heaters must always be protected with a mesh cover due to their extremely hot surfaces and are best managed with a pulse proportional thermostat. Their use is limited among geckos and pygopods, as such high Ceramic heaters temperatures are rarely required. However, they are useful for heating the air around a bank of enclosures.

GLOBES By far the most popular heating method, globes are convenient and accessible to all. They are popular for use with pygopods, but less with geckos due to their nocturnal nature. Different globes suit different purposes.

Standard Incandescent Globes These globes provide moderate dispersed heat to broad basking sites and heat the air in part of an enclosure. They are suited to species that bask in temperatures of 25oC–28°C or for heating an page 52

enclosure at night. Temperature can be influenced by the wattage of the bulb and the distance of the bulb from the basking site. Although less efficient at heating than reflector bulbs, standard incandescent globes are significantly less expensive. Unfortunately, these globes are being phased out of general usage as part of energy efficiency measures.

Reflector Globes These globes are generally used in down lights and provide directional heat through the reflective surface inside the bulb that focuses the light downwards, usually in a 30–80 degree angle. They are ideal for use with any diurnal species as they produce bright light and intense heat over a small area. They can be positioned at one end of the enclosure and will establish an appropriate heat gradient beyond the basking site. Similar to incandescent globes, reflector globes are available as Bayonet and Edison screw mounts and will fit any commercial light fitting. The main disadvantage of these globes is their expense when compared to incandescent globes. However, they are more affordable than ‘reptile lamps’.

Reptile Lamps These globes are purpose built and designed to provide specific types of lighting under specific circumstances, such as ‘moonlight’ globes for night heating and ‘daylight’ globes for diurnal basking. They invariably do what they are designed for very well but it is debatable whether they are more efficient than other globe types. Reptile lamps are almost always designed with an Edison screw fitting, therefore, appropriate light fittings must also be purchased. Although long lasting, they are expensive.

Halogen Bulbs These globes are also known as quartz halogens and dichroic halogens. They are small, highly focused and intense heat lamps suitable for very small enclosures or for use as multiple focused beams within a single enclosure. They are ideal for providing intense heat in a very small area without considerable penetration into the rest of the enclosure. Halogen bulbs are suitable for almost any heating purpose, including use in small enclosures housing small species as the heat can be focused precisely with little lateral spread—they come with only a 10–30 degree beam. Several halogen bulbs will be needed when heating large species to achieve a significant spread of heat. They are useful to aim heat onto the tops of vegetation within enclosures housing species such as small pygopods. Halogen bulbs can be used in combination with a dimming unit to achieve precise temperature gradient control. They are available as low voltage 12V lamps that require transformers to be fitted or 240V units—designed to fit into specific sockets and are also available with a standard Bayonet mount base. Some brands claim to supply significant UV-A and UV-B light if the safety glass filter on the front of the bulb is removed. However, the UV level can be excessive when used at distances below 20cm for 25–30 degree beams (240V), below 40cm for 10 degree beams (240V) and below 50cm for 12V units. The newer generation incandescent replacement halogens such as the Philips Halo SpotoneTM are ideal for heating. They are available as a 30 degree 50W halogen bulb with an Edison screw or Bayonet base, allowing them to be used in a standard light fitting. On a terracotta tile, basking temperatures of 45°C are achieved at a distance of 10–12cm and 30°C at a distance of 17–20cm— making them an ideal alternative to a 40W reflector globe. Unfortunately, when the glass cover is removed their UV-B production is appalling and they are not worth using in this manner. page 53

These globes produce heat in a similar way to ceramic heaters and provide visible light with a moderate red glow. Their use is limited among geckos and pygopods.

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Infrared Globes

Mercury Vapour Lamps (MVLs)

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‘Sunlight’ and ‘moonlight’ reptile lamps

Halogen bulbs (left to right) 12V, 240V, Bayonet mount 240V and 240V with glass filter removed D BROWN

Many enclosures are surprisingly not designed with heating in mind. Therefore, the positioning of heat lamps within an enclosure is often a task that causes some concern. When positioning heat lamps remember to— • Move basking sites to the lamp if light fittings are mounted high on the ceiling. Basking branches may have to be elevated or placed on a raised platform. • Be aware of any support structures that may melt or burn if light fittings are mounted outside of the enclosure, such as on the mesh lid. • Use only heat resistant mesh if light fittings are to be mounted on a mesh lid. This mesh will absorb, reflect and block some heat penetration. • Position light fittings mounted within the enclosure in such a way occupants are unable to roost on the bulbs themselves— they may be slow to wake when the lights switch on and the globe begins to heat up, resulting in burns. A wire cover may prevent this, although I have observed small pygopods enter protective wire cages only to become disoriented and entangled when the light switches on. • Mounting light fittings inside glass tanks can be difficult. Use electrical mounting blocks secured by a silicon sealant suitable for aquarium manufacture to the glass enclosure walls. This supports the actual light fitting and accommodates the wiring. Improve the stability of these attached mounting blocks by marking the base of

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These globes produce heat, light and UV-B light. They are generally too powerful to use Incandescent bulbs and reflector globe with geckos and pygopods.

Using a mounting block to attach a lamp to a glass surface

the mounting block with several small holes or

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scratches to give the silicon something to grip to. These mounting blocks then become the base upon which you attach a lamp fitting. • I recommend using adjustable light sockets that can be directed downwards at a 45 degree angle. Alternatively, a simple angle bracket constructed from galvanised steel or aluminium can be stuck to the glass using silicon or double-sided tape. This acts as a base upon which a ‘clamp lamp’ can be attached. IKEATM sells a wonderful range of ‘clamp lamps’. • Position heat lamps towards one end of the enclosure to allow a heat gradient to be established and to encourage air flow from one area to another. • Use in-line dimming units such as the IKEA DimmaTM in small enclosures to regulate maximum temperatures and avoid overheating. Commercial ‘clamp lamp’ from IKEATM

LIGHTING THE SCIENCE OF LIGHTING The provision of appropriate lighting is important for the general wellbeing of many reptile species. There is much debate regarding the species that do and do not require lighting and what types of lighting are suitable. Generally pygopods and gecko species that actively bask—for example Strophurus spp.—benefit from UV lighting, as do those that lay hard-shelled eggs such as Gehyra, Cyrtodactylus, Christinus and Heteronotia species. Lighting can be broken down into visible light that allows us to see our reptiles and reptiles to see each other, infrared that produces heat, Ultraviolet A (UV-A), Ultraviolet B (UV-B) and Ultraviolet C (UV-C).

Visible Light Any type of incandescent bulb or fluorescent tube will supply visible light.

Infrared This is utilised predominantly for its heating properties.

Ultraviolet A (UV-A) This essential form of light occurs in sunlight at wavelengths of 320–400 nanometres (nm) providing beneficial behavioural and psychological effects. Although these effects are difficult to measure, it is well known that direct sunlight causes geckos and pygopods to behave differently than when exposed to artificial light. UV-A has no impact on vitamin activation but is a part of a reptile’s visible spectrum. Within it, they can see colours and patterns that are not visible to humans but which are important in interactions between individual reptiles. Geckos and pygopods also recognise UV-A reflective markings on plant and insect food items. UV-A is often supplied with UV-B or via full spectrum lighting. Determining the required level of UV-A is impossible due to the varying needs of each species. The average UV-A level on an average sunny Australian day is 2690microwatts/cm2/day—very few lamps approach this level—most provide levels of 300–800microwatts/cm2. page 55

Ultraviolet B (UV-B) This form of light occurs in sunlight at wavelengths of 290–320nm and is directly responsible for the activation of vitamin D3 precursors in the skin of reptiles. Standard incandescent lighting or full spectrum lighting does not supply UV-B. It is usually provided through specially designed UV-B bulbs or tubes—choosing the most suitable can be confusing. The average UV-B level on an average sunny Australian day is 250microwatts/cm2. Depending on the time of day, actual exposure may range from 50–500microwatts/cm2. As a reptile does not bask all day, a realistic goal to achieve is UV-B levels of 50–200microwatts/cm2 at the recommended basking distance. Areas in central and northern Australia have higher UV-B readings than areas in the south. Although it will vary from species to species, the average amount of UV-B required to achieve appropriate metabolic outcomes in a diurnal reptile is calculated to be 300microwatts/cm2/ day. For example, this means that on a cloudy day with UV-B levels of only 50microwatts/cm2 a pygopod would need to bask for six hours to achieve the same UV-B exposure that could be achieved with two hours of sunlight on a summer morning at 150microwatts/cm2 of UV-B. To fully understand the purpose and importance of UV-B to reptiles, the metabolic processes of the body exposed to UV-B must be understood. The following diagram is a simplified version of this metabolic pathway. Skin is exposed to UV-B in sunlight Provitamin D in the skin is converted into previtamin D3 by UV-B exposure Warming of the skin allows the conversion of previtamin D3 into vitamin D3 Vitamin D binding protein transports vitamin D3 into the bloodstream Vitamin D3 is transported to the liver where it is converted into Calcediol (hydroxylated vitamin D3) Calcediol is transported in the blood to the whole body In the kidneys, Calcediol is modified into the hormone Calcetriol Calcetriol governs calcium metabolism by controlling the absorption of calcium from the gut and bones, among other actions. Calcetriol is also important for the functioning of the immune system, cardiovascular system and as part of the body’s anti-cancer mechanisms. In these cases, the conversion from circulating Calcedriol to Calcetriol occurs locally in the cells involved. Calcediol lasts only for a short time in the bloodstream—possibly a few days to a fortnight—and, as this circulating volume acts effectively as the body’s store of vitamin D3, it must be topped up regularly. page 56

Vitamin D3 toxicity cannot occur in a naturally basking lizard—the body has safety feedback mechanisms to prevent this from occurring. When the warming body converts previtamin D3 into vitamin D3 it also produces the two by-products lumisterol and tachysterol, which have no physical function in the body. When a large amount of vitamin D3 has accumulated, these by-products also accumulate, switching off the manufacturing process. It is also proposed that these by-products act as ingredients for the formation of further previtamin D3 in future metabolism. If the body produces lots of vitamin D3 and cannot use it fast enough, further UV-B exposure will destroy the excess vitamin D3 breaking it down into three substances that accumulate and act as further feedback chemicals. The process that occurs depends on what wavelength of light is being encountered, as each metabolic conversion requires a different wavelength—this, in turn, depends on the time of the day. During early morning and late afternoon, wavelengths less than 300nm are not present because sunlight must pass through a thicker atmospheric layer and at an angle. Therefore, provitamin D3 to previtamin D3 conversion is essentially switched off. Later in the day when the sun is higher and the atmospheric thickness has changed, the body is exposed to higher wavelengths that switch that conversion mechanism back on. At the same time, the higher wavelengths switch on the mechanisms that convert lumisterol and tachysterol back to previtamin D3 to ensure the body does not run out. Species located close to the equator, including those in northern Australia, are exposed to higher wavelengths than those in subequatorial regions because the sun is always higher in the sky. Cloud cover can essentially have the same atmospheric thickening effect and will influence what wavelengths are available to use on any given day. Reflectance from adjacent objects will also influence exposure to UV-B and may allow an animal standing in apparent shade to receive UV-B reflected off glossy leaves or rocks nearby. UV-B uptake varies according to a reptile’s skin, influenced by the place of origin and current location. As humans are aware, repeated sunburn is unpleasant and dangerous. Species of reptiles from high UV-B areas possess more efficient protective mechanisms in their skin to impede UV-B penetration—allowing for sufficient UV-B for basic functions but no more than necessary. Conversely, nocturnal or cryptic species, such as most geckos and some pygopods, have skin with less protective mechanisms as they are not usually exposed to UV in quantity and do not naturally require protection. Additionally, various parts of the body have varying levels of UV-B penetration. For example, the skin on the belly and under the throat of a bearded dragon allows for three times the UV-B penetration than the skin on the back. This makes sense as belly and chin skin is rarely exposed to direct sunlight, therefore protection is unnecessary. However, during the peak of the day, a bearded dragon may receive optimum UV-B uptake while standing in full shade due to reflectivity from the ground shining onto the less protected belly and chin skin. A gecko with few protective mechanisms, hiding among foliage or in a crack in the rocks during the day, may potentially receive its full dose of UV-B by just spending minutes in dappled specks of sunlight that penetrate the canopy or reflect off rocks or leaves. Some species can determine the levels of vitamin D3 in their skin and will modify their behaviour accordingly, seeking shade when nearing overexposure or sunlight when more is required. This may explain why some captive species actively and preferentially bask in slight beams of sunlight when they have access to much more effective basking conditions under a nearby lamp. The inclusion of a light gradient in addition to a heat gradient should be considered when placing UV-B light sources in an enclosure. This allows occupants to move in or out of varying levels of UV-B as they feel it is needed. Compact UV-B tubes make this easier than traditional long fluorescent tubes that span the whole enclosure. page 57

A new syndrome caused by excessive UV-B exposure—named photo-keratoconjunctivitis— has been associated with the use of some brands of high UV-B producing compact lamps. This has occurred because a range of 10% compact globes produce low wavelength non-solar UV-B levels due to the presence of ‘phototherapy’ phosphors in the lamps, causing a syndrome typified by painful and puffy eyes, lethargy, lack of appetite and skin damage. It is equivalent to snow blindness or arc welder flash syndrome and is caused by damage to the corneal or eye surface and the conjunctiva or lining of the eyes. It does not affect the deeper areas of the eye or cause blindness. Recovery takes 2–14 days once the lamps are removed. Medication is only required if the eyelid skin becomes infected. This syndrome could also potentially be caused by placing compact bulbs or mercury vapour lamps closer to the animal than is recommended. As the heat output of mercury vapour lamps is comparatively low, many keepers move the bulb closer to the lizard to attempt to achieve a dual purpose, essentially overdosing it with UV-B. As these lamps are unlikely to be used for heating anything but the largest diurnal pygopod, it is not likely to be an issue in this group. The use of metal reflectors on compact lamps plus modifying the lamp position could also potentially cause excessive UV-B exposure—keepers may not be aware of the six-fold improvement in output when using these. UV-B exposure may also be affected by the artificial components of an enclosure, such as wire or glass sheeting. A single layer of average glass can block 98.5% of UV-B. A double layer of glass, such as a window and then a fish tank wall, can block almost 100% of UV-B. Excess UV-B is not common but can occur if a nocturnal species cannot access a hide area, if UV-B supplementary lights are placed too close to a basking site or if UV-B lights are too powerful or used on specimens with abnormal skin features, such as some Albino reptiles. As expected, the UV requirements of predominantly nocturnal or crepuscular species are low, provided that dietary vitamin D3 is available. Almost all of these species are insectivorous and must acquire their vitamin D3 supply through these foods. If good quality food is provided then UV-B supplements should not be necessary. Diurnal species have much more varied diets and will actively bask to obtain UV-B, therefore synthesising much of their own vitamin D3. Vegetarian species consume diets that are generally low in vitamin D3 and high in vitamin D2, not required by reptiles. Some keepers recommend against exposing these species to UV-B and providing all vitamin D3 through the diet. However, ascertaining the correct level of dietary vitamin D3 is beyond the scope of the average herpetologist—although many attempt to by using powdered supplements. Supplementing vitamin D3 in favour of UV exposure essentially bypasses a reptile’s safety mechanisms. Therefore if UV exposure is limited, vitamin D3 should be supplemented carefully and sparingly. Although precursor vitamin D3 is short-lived in the bloodstream, it is retained long enough that constant supplementation is not required. Intermittent supplementation, such as in two out of three feeds or three out of five feeds, allows the body to self-regulate its acquired dietary vitamin D3 and avoid over supply.

Ultraviolet C (UV-C) This form of light occurs at wavelengths of 180–280nm and is harmful to living cells. It is filtered from sunlight by the ozone layer— therefore, individuals are not usually exposed.

LIGHTING OPTIONS As with heating, there are numerous methods and means of appropriately lighting an enclosure. Different products produce different results. When providing lighting, it is not a case of plugging page 58

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in a light and walking away. The supply of appropriate UV-B lighting requires proper thought as to the requirements of the species being kept, the type of enclosure and the lighting options suitable for that enclosure as well as consideration of the costs, advantages and disadvantages of each type of lighting. Each lighting product varies in its cost and reliability—performance may even vary greatly within certain batches of the same product. When it comes to the amount of UV-B light emitted and the rate of decay, you get what you pay for—less expensive products generally perform poorer than good quality products. It is also not uncommon for poor quality products to vary in the reliability of their output. The only method of determining a product’s UV output is with a UV meter. Some keepers use these to maintain quality control over the UV-B products in A commercial UVB meter. The measurement use and to ascertain when they require replacing— of 35 microwatts/cm2 was measured on a allowing them to ascertain decay rates, to lengthen cloudless winter afternoon in full sun the life of an aging UV-B unit by modifying the light’s position or the basking height if the UV-B emission starts to weaken. Following are the available lighting options.

UV-B Emitting Fluorescent Tubes These lights operate when an electric current passes through a sealed glass tube containing an inert gas such as argon, and a small drop of mercury. The electricity vaporises the mercury and excites the mercury atoms sufficiently to produce light—mostly UV and blue and green visible light. Normal fluorescent tubes are constructed from a type of glass that absorbs most of the UV produced—the remainder is absorbed by the phosphoros powder which converts energy from the UV light into visible light. UV-B emitting tubes contain less phosphoros powder than a standard fluorescent lamp and non-absorbing silica quartz glass. The length of the tube determines its wattage—in a standard T8 (25mm diameter) tube 450mm equals 15W, 600mm equals 18W, 900mm equals 30W and 1200mm equals 36W. UV-B emitting fluorescent tubes are usually labelled as 2%, 5% or 10% UV-B, depending on the percentage of UV-B they emit. Some may also be labelled according to UV-A output. A 5% UV-B, 30% UV-A tube will ideally produce 5% UV-B and 30% UV-A—the remaining 65% will be visible light. Full spectrum lighting produces only UV-A and is generally only useful for UV-A—which is good for plant growth—or the visible light it produces. UV-B fluorescent tubes provide a diffuse UV-B glow, low heat and a uniform light gradient in a vertical fashion. The heat from the light and ballast combined can add up to 7°C to the ambient temperature in an enclosed space. As their output is not excessively high, these tubes should be placed approximately 15–20cm from the basking area. In most enclosures this will require basking branches to be extended to the maximum height of the enclosure. The intensity of the light produced will halve as the distance away from the light doubles. The use of a curved reflector doubles the UV-B output by focusing any lost light downwards. page 59

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Double fluorescent tubes will double the output, however, this is equal to the same as one tube with a reflector. Double tubes with reflectors triple the output. Mesh covers will significantly reduce UV-B output. A disadvantage of all UV-B emitting devices is a process known as decay. As soon as a new tube is switched on and achieves a stable temperature, reactions occur between the phosphoros coating, mercury, tungsten and electrical components. These reactions result in a gradual reduction in the lamp’s UV-B output—initially approximately 5–10% in the first 100 hours of use, then a slower decline over the rest of its working life. The UV-B output never ceases but it may reach a point where the intensity is ineffective for vitamin D3 metabolism. Tubes should be replaced every 6–12 months or as indicated by a UV meter.

Black Lights

Often used in nightclubs as a decorative effect to enhance white colouration, black lights are specific UV-producing fluorescent tubes. The Black Light BlueTM lamp (BLB) is not recommended—it produces dangerously high levels of UV light. The NEC T10TM black light is widely used in herpetological circles and produces ideal levels of UV-A and UV-B at distances of 20–40cm. These lights decay rather fast and should be replaced every NEC-T10TM black light and UV-B tubes six months. They should be paired with a standard fluorescent or full spectrum tube, as they produce inadequate visible light.

Compact UV-B Emitting Lamps

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These narrow fluorescent tubes have been modified to fit into a small area by twisting and compressing the tube and mounting it on a normal light fitting, usually an Edison screw. They require no further modification as the ballast starter is mounted in the base.

Compact UV-B lamps

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Mercury Vapour Lamps

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UV-B compact lamps provide a diffuse but intense UV-B glow directed downwards, low heat and a uniform light gradient in a vertical fashion. Their output is higher than a fluorescent tube but excessive, therefore they should be located so that the basking distance from the tube is approximately 15−25cm, although it is much easier to place these lamps within an enclosure so proximity to the lamp is enhanced. The use of reflectors improves the output of compact UV-B emitting lamps. Although white reflectors have little influence on the output of these lamps, shiny metal reflectors will enhance output by as much as six times. Some compact lamps are fitted with purpose-built reflectors that are covered with a mesh screen to protect the reptile from burns—the light surface gets hot (200oC−250oC), despite not emitting much heat into the vivarium. These are designed to reduce glare for the keepers. The mesh screen Compact UV-B light and reflector causes significant UV-B blockage and essentially negates any benefits of the reflector. These lamps emit very good levels of UV-B and are available in four types—spot, flood, narrow flood and high intensity. All types use a standard Edison screw base. Many keepers attempt to use these as dual-purpose bulbs to provide UV-B and heat, however they are not designed for this purpose and generally fail in this respect. Some mercury vapour lamps produce excellent UV-B but poor Commercial light hoods heat and others produce excellent heat but insufficient UV-B at a safe heating distance. They are generally not suitable for use with geckos and pygopods.

THERMOSTATS The sole purpose of a thermostat is to maintain the temperature of an enclosure above the recommended minimum temperature and below the recommended maximum temperature. This is achieved by supplying or denying power to the principal heating element. The time between subsequent on and off cycles is known as the hysteresis period. In enclosures housing nocturnal species, a thermostat must maintain the temperatures of an enclosure and basking sites within the optimal zone for that species. With diurnal species, thermostats are generally recommended for use as a safety mechanism—this is because a thermostat maintaining the temperature of a basking lamp can only do so by switching that lamp on and off or by dimming it—neither of which is conducive to establishing a basking site. A thermostat should be set up to ensure that if the enclosure reaches a maximum temperature, at which all heat gradients are lost and the entire enclosure is potentially going to overheat, all power is shut off. This is essential on hot summer days. Choosing the right thermostat for an enclosure will reduce power use and extend the life of your heating elements. Ideally, heating elements controlled properly should only be active 50% of the time. page 61

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If the heating element is activated more often than it is switched off, then it is too small for the job at hand and should be replaced with a unit of higher wattage. If the heating element is rarely on or activated for short bursts only, it is too powerful for the enclosure it is required to heat. There are four major types of thermostats available— probe, on/off, dimming and pulse proportional.

Probe Thermostats

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Probe thermostat

Designed to control temperature on an on/off basis in dry environments, probe thermostats are controlled by fluid contained in a long, thin metal tube, which activates a switch when it expands in hot temperatures. When the temperature is cool, the fluid contracts and the switch is deactivated. The desired temperature is simply set on the dial. These thermostats are suitable for use with heat pads, heat cords or heat bulbs. They can also be used for heating insect breeding facilities and incubators. The major disadvantage of probe thermostats is that they are somewhat imprecise at maintaining temperatures with a spread of control of +/- 1oC–1.5°C.

On/Off Thermostats Essentially the same as a probe thermostat, on/off thermostats provide more precise control over the temperature. They can be used with heat pads, heat cords or heat bulbs.

Dimming Thermostats D BROWN

On/off thermostat

These thermostats regulate the power output rather than switching the power source on and off. They work at full strength when maximum heat is needed and utilise less power when slight increases in heat are required. They are suitable for all heating elements, including light bulbs. As the bulbs are not constantly switching on and off, their longevity is greatly extended.

Pulse Proportional Thermostats These thermostats use a unique system of power supply where the electricity required is pulsed through the wires at regular intervals, determined by the amount of power needed. The electricity is pulsed through at maximum rate when maximum heating is required, and Pulse proportional thermostat

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at levels sufficient to keep the device just kicking over when small amounts of heat are needed. Heating elements attached to these devices rarely ever run at full power. These thermostats are not suitable for use with light bulbs as the bulb would constantly pulse on and off. They will also damage fluorescent tubes.

HUMIDITY The relative humidity within an enclosure is directly related to the inside temperature and the amount of moisture available for evaporation. For some species, high relative humidity of more than 80% is important on a daily basis. For others, high humidity is important during periods of skin shedding, but not at other times. A large proportion of species kept in captivity originate from arid or semi-arid environments where low relative humidity of less than 30% is preferred. There are many confusing pieces of information in overseas texts that assume Australia is a tropical paradise and recommend high humidity for virtually every species of Australian gecko and pygopod. Enclosure humidity may be supplied through a range of methods including spraying or misting, substrate soaking and the provision of wide water containers with large evaporative areas. Local areas of humidity, which do not influence the rest of the enclosure, may be supplied using small containers of moist substrate or moistened substrate placed under a hide area. Before installing these measures, you must consider if the enclosure will tolerate regular high humidity. Despite their apparent impervious surface, melamine cages can be damaged by excessive humidity while glass enclosures will not. Generally, supply rainforest and wetland species with a high humidity of more than 80%, species located naturally within 100–150km of the coast with moderate enclosure humidity between 40–60% and all arid and semi-arid species with a low enclosure humidity of less than 30%. The supply of high enclosure humidity can be demanding and may require daily or twice daily spraying of the enclosure with water and/or the provision of a moist substrate—this should be remoistened each time you spray or heavily moistened once or twice a week. This treatment is suitable for approximately 5–10% of Australian species. Unfortunately, many overseas keepers provide this level of humidity for all Australian species, regardless of their origins. The supply of moderate enclosure humidity generally requires much less effort and may be as simple as providing a permanent water facility and spraying the enclosure with water once a week. This treatment is suitable for approximately 30–40% of Australian species. To avoid high humidity or attain low humidity, supply small water bowls or supply water intermittently for a few hours each day or for a few days per week and maintain relatively dry substrate by not overfilling water bowls and resisting spraying. Although arid and semi-arid species should not be devoid of humidity, they are not designed to survive in wet environments. Many species have access to a small pocket of increased humidity in the wild—be it deep in a soil crack or beneath some fallen leaves—important at times such as skin shedding, egg laying and during excessively dry conditions. The remainder of the time, these species are exposed to dry conditions, excluding rainfall and heavy dewfall. As a result, they have adapted to these conditions and may develop skin disorders, respiratory problems and infections when exposed to moisture for long periods of time or if exposed regularly with no means of avoidance. There is no obligation to regularly spray these species—instead supply a small hide site containing moist substrate that the species may use when it feels the need. This moist area should not be the only hide site available. It can be either a small moist container or one of multiple hides that has the substrate underneath moistened once or twice per week. page 63

Another problem associated with excessive water spraying in enclosures accommodating geckos and pygopods other than rainforest species, is the development of biofilm. In the wild, many species rarely come into contact with a constant surface layer of water as is created when an enclosure is finely misted all over. This layer of surface moisture is created by spraying or finely misting an enclosure and is fractions of a millimetre thick. Within this biofilm are many of the bacterial, fungal and parasitic diseases that lizards are prone to, and which require moisture to survive and to be transported from one host to another. Captive bred geckos and pygopods are brought into closer and more regular contact with these pathogens than in the wild where many species rarely come into contact with a constant surface layer of water. The biofilm is fast occupied by pathogens residing on the surface of substrate components, faecal material, enclosure walls and inside the spray bottle. Occupants that lick these surfaces in order to access water will invariably also consume some of these pathogens. Additionally, pathogens on the occupants’ skin surface and mucous membranes will have an opportunity to move to other parts of the body when a water film covers the surface of the body. Whether ingestion or internal absorption of this biofilm through the eye or ear causes an individual any problems depends upon— • The species involved. Arid zone species are unaccustomed to biofilm, whereas rainforest species encounter it daily. • The quantity of pathogens in the biofilm. Dirty cages will produce a more pathogen concentrated biofilm than regularly cleaned cages. • The type of pathogens present. Water borne bacterial organisms such as Pseudomonas or Aeromonas can survive for long periods while awaiting an appropriate biofilm in which to activate. Some flagellate protozoa must come in contact with the biofilm while the faecal material in which they reside is still wet. • The health of the individual. Geckos and pygopods suffering from a pre-existing disease shed greater numbers of pathogens. For instance, subclinical coccidia infections in specimens accommodated in consistently dry enclosures may rapidly turn into epidemic clinical infections following enclosure spraying. This is because the organisms become available to many more individuals, at higher concentrations, than were previously encountered under dry conditions. • The origin of the individual. Captive bred geckos and pygopods will have lower natural parasitic flora than wild caught geckos and pygopods. Therefore, their faeces will contain less pathogens which, in the presence of a biofilm, are less infective to others. • The origin and type of substrate. Recycled and dirty sand will harbour more pathogens than clean, fresh sand. To decrease the risk of water borne diseases, you should accommodate healthy, captive bred specimens in a clean environment with fresh substrate that has faeces removed regularly. Any lapse in standards may tip the balance. The risk of disease may increase when previously dry conditions suddenly become excessively wet—for example, when an established group in a previously dry enclosure are heavily sprayed for a few consecutive days and drink large amounts of biofilm containing high levels of faecal pathogens. In this situation, previously high pathogen levels would have been of low risk because of the absence of the biofilm and the rapid drying of faeces. To spray or not to spray—it’s a personal choice.

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FEEDING METHODS AND NUTRITION

Foods suitable for geckos and pygopods can be broken into three broad categories—invertebrate food items, vertebrate food items and artificial diets.

INVERTEBRATE FOOD ITEMS There are many different invertebrate food items suitable for lizards—many may be cultured at home, collected or purchased commercially. The most common invertebrate food items are crickets and cockroaches. Less commonly fed items include mealworms, mealworm beetles, Zophobas worms, flies, fly larvae, fly pupae, slaters, silkworms, termites, earthworms, locusts, spiders, fruit flies, waxworms and wild fodder. Each of these food items has a range of positive and negative attributes. Some also have specific uses, such as locusts and termites, and others are accepted more generally. Each live food item, its use and—where relevant—how to culture it, will be discussed below. A comparative nutritional table is provided at the end of this section.

Crickets—Acheta domestica

D BROWN

Crickets form part of a staple diet for 70–90% of small and medium reptile species across all families. As there is no ideal live food for lizards, crickets are the best of a bad bunch—with one of the lowest fat levels, moderate protein levels but a poor calcium to phosphorus ratio. The latter can be improved by including a high calcium supplement in a cricket’s diet in the days prior to feeding—known as gut loading—or by coating the cricket in a calcium supplement powder immediately prior to feeding—referred to as dusting. (See Dusting on page 82 for more detail). Crickets are generally required to be fed live for geckos and pygopods.

Cricket sizes (left to right), adult female, adult male, two-thirds, one-half, one-third, 25-days-old, 20-days-old, 10-days-old and pinhead

Cockroaches Cockroaches form part of a secondary staple diet for many species—predominantly larger species, due to the larger size of this food source. In Australia, lizards are fed primarily on one cockroach variety known here as speckled feeder roaches or woodies, and overseas as lobster roaches. These cockroaches have wings but do not readily fly and will not usually colonise a location if they escape. In other countries there are many other cockroach species suitable for use. page 65

D BROWN

Feeder roach sizes (left to right), one-third, one-half, two-thirds, freshly shed two-thirds and adult

D BROWN

Nutritional data on cockroach species is difficult to obtain and each cockroach connoisseur has their reasons why their variety is better than others, such as meat-to-wing ratios. Generally, cockroaches have slightly higher fat levels than crickets, lower protein but a much better calcium to phosphorus ratio compared to crickets. This ratio may be further improved by feeding them high calcium vegetables or through calcium dusting.

Mealworms—Tenebrio molitor

Mealworms are often thought to be a staple part of a nutritional diet, however they are unsuitable primary dietary items as they are high in fat and possess very low calcium to phosphorus ratios. Their tough chitinous exoskeleton is hard to digest. Excessive consumption of mealworms may predispose an individual to metabolic bone disease (MBD) and may lead to gut impaction. Therefore, they should not comprise more than 10% of the overall diet King mealworm Zophobas (top) and mealworm and should generally be avoided by geckos and pygopods. The suitability of mealworms may be slightly improved through gut loading or dusting. Mealworm beetles may also be fed—they have higher levels of protein, lower fat but a poorer calcium to phosphorus ratio. Mealworm pupae are an alternative nutritionally similar to mealworms.

King Mealworms or Superworms—Zophobas morio King mealworms or superworms are similar to mealworms but are three to four times larger in size. They are much higher in fat than regular mealworms and, although they possess a better calcium to phosphorus ratio, this is still very low. They are generally too large for gecko and pygopods species. They should not be confused with ‘Super Mealworms’, which are regular mealworms influenced by hormones so they continue growing and do not pupate. page 66

D BROWN

Maggots/Flies/Pupae— Musca vetutissima

These food items are often overlooked as a food source for lizards, although they are commonly fed to frogs. Much of their unpopularity is due to Bush fly, larvae (maggots) and pupae their affiliation with rotting flesh—however this is not necessarily required to produce flies or maggots. The principal cultured species is Musca vetutissima although occasionally other species may be available commercially. All life stages are readily accepted and they possess higher protein levels, lower fat levels and a better calcium to phosphorus ratio than mealworms. They are similar to crickets, but with a higher calcium to phosphorus ratio. Maggots (or fly larvae or gentles) should be offered as part of a mix of foods, as their rubbery exoskeleton can be difficult to fully digest in large amounts. However, impactions have not been recorded. Dusting with calcium supplements may improve their nutritional value. The provision of adult flies is quite simple and provides valuable behavioural stimulation for small dragons, geckos and skinks. Simply place some fly pupae in a shallow bowl, such as a milk bottle lid or small terracotta saucer, with a 6mm x 6mm piece of wire over the top to prevent the pupae from being eaten. Over a period of 2–3 days, the flies will emerge from the pupae and crawl onto the wire mesh to dry and stretch their wings. A light layer of calcium powder in the bottom of the dish will allow some calcium to stick to the moist flies as they emerge. Often lizards will wait around the edges of the lid or saucer for a new morsel to appear—otherwise, they will spend considerable time stalking flies throughout the day. The obvious disadvantage of providing flies as a food source is the risk of the food item escaping. Well-sealed lids are the key to preventing escapes. Also, do not provide too many pupae or the enclosure will become overrun with flies. One level teaspoon of pupae contains about 250–300 pupae, which will generally yield 220–270 flies—assuming a 90% pupation rate.

Slaters Slaters are crustaceans, not insects, and are a staple of many subtropical and tropical reptile species in the wild. They are rarely used in captivity and little nutritional data is available on them. Slaters range in size from 5–25mm. They should be fed in a similar manner to cockroaches—the main difference is that slaters are poor climbers compared to roaches. They are accepted by most terrestrial species.

Silkworms—Bombyx mori and other Caterpillars Silkworms—technically called Silk Moth caterpillars—are ideal for all lizard species and are one of the most nutritionally balanced insects available. Their main disadvantage is that they are seasonal and available for only a few months of the year. There are some methods for extending their reproductive period—but these may not be useful if you rely on the silkworm’s natural food— mulberry leaves—which are also seasonal. Silkworms are generally sold commercially as large specimens suitable mostly for large pygopods, which will kill them and then lap up the juices. Not all caterpillars are suitable food items—many wild caterpillars secrete toxic materials into their skin or absorb toxins from their diet to make them unpalatable. Generally, avoid hairy or ornately decorated caterpillars. Lawn grubs are the exception and may be collected quite easily by placing a few wet hessian bags on the lawn after heavy rain or watering, allowing the grubs to congregate under them. Do not leave these bags too long or you may kill patches of the lawn. page 67

D BROWN

Termites

An important food source, termites may make up to 75–100% of many species’ diets in the wild. They are particularly suited for feeding to small terrestrial geckos and their hatchlings and small pygopods. They are higher in protein than crickets, but little other nutritional data is available. Termites may be stored in the refrigerator for 24 hours after collection. In the wild, they are usually obtained by Termites—showing alates (winged forms), soldiers and workers specimens scratching the encasements that the termite makes around grass stems or by feeding on winged forms (alates) rather than from large termite nests. There are several methods of harvesting termites—in situ milking, nest collection and storage. They can also be cultured—but be careful—the termite species ideal for culturing may also colonise your home.

Earthworms—Lumbricus terrestrius

R PORTER

Earthworms are well accepted by lizards—many wild specimens feed regularly on earthworms obtained from leaf litter on the ground after rain. They are readily available at most garden centres, bait stores in freshwater areas, pet shops and hardware stores. Earthworms are nutritionally balanced, high in protein, low in fat and with high calcium to phosphorus ratios. There are not many species of gecko that regularly feed on earthworms but they may be offered to large ground dwelling species such as Cyrtodactylus.

Locusts—Chortoicetes terminifera

Although locusts are not used often in Australia, they are popular in other countries for feeding to large specimens. They are low in protein, high in fat and possess calcium to phosphorus ratios similar to that of mealworms. Although breeding is lengthy, locusts reproduce easily and grow fast—newborn locusts are equivalent to the size of small Locust sizes—adult, half grown and hatchling crickets. Some susceptible people may experience an allergic reaction to skin shed from locusts. Locust hatchlings may be used as a substitute for crickets.

Spiders Spiders are suitable for feeding to large pygopods including Pygopus and Paradelma species. They should be served dead so lizards may lap up the body juices when they open the body cavity. Spiders are supplied as wild caught specimens. Small wolf spiders Lycosa species, which are common in the wild and readily accepted, can be collected on the ground at night using a torch to locate them by their brilliant green eyeshine. Very large spiders such as Huntsmans Isopeda species can be offered, but are so large they may injure a specimen—if offered they should be served dead. page 68

Fruit Flies—Drosophila species

D BROWN

In Australia, fruit flies are rarely fed to reptiles, despite being a popular food source among aviculturists. This is predominantly because the ‘wingless’ varieties and the diets for them are not commercially available in Australia, as they are overseas. They are small and are best suited for feeding to small geckos. Fruit flies are difficult to source commercially but may be obtained from some universities. In outside enclosures, fruit flies may be readily cultured on site and provide a free food source. They have a very high protein level, very low fat, and a very low calcium to phosphorus ratio. Using high calcium fruits for culture may compensate for this—assuming that some gut filling in the maggots will be passed on as nutrition once pupated and hatched.

Snails—Helix aspersa and other species

Waxworms—Galleria mellonella

D BROWN

Cyrtodactylus tuberculatus will readily take baby garden snails Helix aspersa or small aquarium snails, presumably using them as a valuable source of calcium during the breeding period. Overall, snails are moderately high in protein, very low in fat and, if the shell is consumed as well, balanced in their calcium to phosphorus ratios. Without the shell, the calcium to phosphorus ratio is very poor. It is important that garden snails are collected from an area A commercial moth trap where snail bait is not used. Waxworms, like fruit flies, are readily available overseas but difficult to find in Australia. Commercial supply is frowned upon by the beekeeping industry as waxworms are a pest to beehives. Another species known in Australia as Lesser Waxworms are sometimes available. Not related to the true Lesser Waxworm, they are the Indian Meal Moth Plodia interpunctella that occurs as a pest in mealworm cultures. They are easily propagated. Waxworms are very high in fat and possess poor calcium to phosphorus ratios. They are most commonly fed to female geckos after egg laying to assist them in regaining body condition.

Wild Fodder D BROWN

Insects collected in the wild, such as moths, flying ants, termites, A commercial moth trap in use with modified catching bag katydids, beetles, bugs and mantids, are all excellent sources of food. Keepers often avoid using wild food items as they are usually concerned about the transfer of intestinal parasites. However, this is of no real significance—it would require the insect to have previously fed on infected lizard faeces—and this invaluable source of high quality food should be used more often. A typical moth trap catch

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Grasshoppers and moths can be easily collected by sweeping a net through long grass. Moth traps can be purchased commercially or homemade using plans that can be found in books and on forums and websites concerning butterfly and moth collecting. Migratory moths can be collected in large quantities and frozen for later use. The nutritional content of each food item varies, as outlined in the table below.

Nutritional Data Averages for Invertebrate Diets FOOD TYPE

PROTEIN (%/Dry Matter)

PROTEIN (Grams per 100 Grams)

FAT (%/Dry Matter)

FAT (Grams per 100 Grams)

CALCIUM TO PHOSPHORUS RATIO Ca:P

Cockroach

53.9

−

28.4

−

1:2.5

Cricket (adult)

64.9

12.9

13.8

5.5

1:7

Cricket (adult on a high calcium diet)

65.2

−

12.6

−

1:1

−

−

−

−

1:6

Earthworm

62.2

−

17.7

−

1.8:1

Fruit Fly

70.1

−

12.6

−

1:10

-

16.1

-

1.4

1:2 (with shell) 1:27 (without shell)

House Fly Maggot

56.8

−

20.0

−

1:3.2

House Fly Pupae

58.3

−

15.8

−

1:3.1

Mealworm

52.7

20

32.8

14

1:10

Mealworm Beetle

63.7

−

18.4

−

1:11

Mealworm Pupae

54.6

−

30.8

−

1:10

Waxworm

42.4

−

46.4

−

1:6

Locust

52.7

−

32.6

−

1:11

Silkworm

53.0

−

20.2

−

1:1.3

Zophoba Worm

45.3

17.4

55.1

17.9

1:4.5

Termite

11.3

14.2

58

−

1.3:1 (soldiers) 1:2 (workers/alates)

Cricket (pinhead)

Garden Snail

The values in this chart may be confusing without knowledge of how they were obtained. Therefore, it is recommended they be critically evaluated on a comparative basis rather than on actual values. Available values vary greatly depending on the diet of the insect, the bias of the researcher and the research method employed. Research carried out by live food companies will sometimes be biased towards their own products. page 70

VERTEBRATE FOOD ITEMS Virtually all reptile families include at least one species that feeds on vertebrate food items such as rats, mice, chicks, quail, guinea pigs, small birds, fish and other lizards. Within the gecko family, vertebrate diets are limited to the large species including Cyrtodactylus, Nephrurus and Pseudothecadactylus. These geckos will accept live or freshly killed mouse pinkies or fuzzies. However, the provision of these food items live may be illegal in some states—check your local regulations. Geckos may need to be teased into accepting freshly killed food items— they are sight feeders and prefer food if it is moving. Most other gecko species are too small in size to eat vertebrate items. Pygopods are generally too small to consume a vertebrate diet—however, some specimens of Pygopus lepidopodus will consume pinkie mice and other pygopods may be converted onto pinkie mice. P. lepidopodus and P. schraderi are reported to consume very small fish such as guppies. The Burton’s Legless Lizard Lialis burtonis feeds almost exclusively on live skinks and geckos—and although some states legislate the keeping of L. burtonis, they do not approve of feeding them live skinks. Vertebrate food items have various features to be aware of.

Rats and Mice

D BROWN

The feeding of these vertebrate food items to geckos and pygopods are limited to pinkie and fuzzie mice. Generally, smaller life stages of mammalian prey such as pinkies and fuzzies are more nutritionally suitable than larger life stages, which often carry higher levels of fat and lower levels of protein. Mice and rats should be fed a quality commercial diet designed for laboratory rats and mice. Cutting corners will alter their nutritional value and usually increase their fat content. Feeding pinkie mice and rats that have a full stomach of milk is equivalent to gut loading with calcium, due to the high calcium component of the mother mouse’s milk. This increases the calcium to phosphorus ratio to the equivalent of an older juvenile sizes (left to right), large adult, regular adult, with more mineralised bones. Mouse weaner, hopper, fuzzie and pinkie

Fish This vertebrate food item seems an unlikely source of food for geckos and pygopods but Pygopus schraderi and Pygopus lepidopodus may feed greedily on small guppies if offered.

Reptiles Feeding other reptiles to reptiles should be avoided for legal reasons (in some states) and to avoid the transfer of parasites. However, this does not seem to affect the Burton’s Legless Lizard page 71

A ELLIOTT

Lialis burtonis feeding on a Pogona vitticeps hatchling

L. burtonis—as an obligate lizard feeder, this species has adapted to cope with high levels of parasite ingestion. The occasional injured captive bred hatchling can be offered to species such as Nephrurus geckos, rather than waste them. The nutritional content of each food item varies, as outlined in the table below.

Nutritional Data Averages for Vertebrate Diets PROTEIN (%/Dry Matter)

PROTEIN (g/100g)

FAT (%/Dry Matter)

FAT (g/100g)

CALCIUM TO PHOSPHORUS RATIO Ca:P

Mouse (pinkie)

64.2

12.3

15.2

3.2

1:1.13

Mouse (fuzzie)

41.80

−

46.7

−

1.1:1

Rat (pinkie)

57.9

12.0

23.7

4.9

−

65−68

−

8−10

−

2:1

FOOD TYPE

Lizard (skink or gecko)

The values in this chart may be confusing without knowledge of how they were obtained. Therefore, it is recommended they be critically evaluated on a comparative basis rather than on actual values. Available values vary greatly depending on the diet of the insect, the bias of the researcher and the research method employed. Research carried out by live food companies will sometimes be biased towards their own products. page 72

ARTIFICIAL DIETS Artificial diets are generally not accepted by most geckos but are occasionally taken by larger pygopods. The types of artificial diets accepted are restricted to sugary fruits such as mango or banana or artificial nectar mixes. Occasionally, protein based mixes including boiled egg, grated cheese or canned dog food may be eaten in small quantities by small pygpods. Paradelma will greedily feed on Acacia sap.

CULTURING INSECT FOOD ITEMS

Crickets are not difficult to breed, however it is time consuming and requires considerable space if a large number of crickets are required. Basically, crickets require food, moisture, heat and egg laying facilities to thrive. I have bred crickets in an old freezer chest heated by two light bulbs—just in case one fails—or by a 60W heat cord run around the bottom of the chest’s walls and connected to a basic probe A small cricket culture thermostat. Hides, a water source, food and a foam block lying on a shallow tray should be placed on the floor. Egg cartons or toilet rolls placed vertically make good hides and allow cricket faeces to fall out easily. A moisture source and foods can be placed in separate takeaway containers. Provide ventilation through openings in the container lid and cover in flyscreen to keep flies, geckos and vermin out. All life stages can be fed with the same diet. Fish food flakes, chick starter crumbles, lucerne pellets, egg and biscuit, crushed mouse pellets and ground puppy biscuits are ideal. Smaller life stages simply require food items to be ground finer. Moisture must be supplied but by a means in which the crickets are not able to drown—newly hatched crickets can drown en masse in a single drop

D BROWN

Crickets—Acheta domestica

R PORTER

Culturing your own insects allows you to supply your lizards with a wide variety of live food. It ensures a continuity of supply, which is not always possible when you rely on commercial suppliers that may run out of stock when demand is high and often favour commercial buyers over small customers. There are many different methods for producing live foods. Following are the methods I have found most successful, including the insect species I have found the least troublesome.

Old chest freezer used as a large scale cricket breeding facility

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D BROWN

of water—this is of less concern with large crickets. Moisture can be supplied via highly moist food items such as orange, carrot or shredded lettuce. Alternatively it can be supplied as a protected water source, such as water crystals or via a sponge that fits tightly in a reservoir such as a coffee or jam jar lid—these must be topped up regularly and cleaned at least one to two times per week. Heat can be supplied via light bulbs, a heat mat or heat cord placed within or under the container being used for culturing. The ideal culture Lid ventilation is essential for cricket culture temperature is 28°C, maintained by a thermostat longevity the same as that used for an incubator. The provision of egg laying facilities is often the most challenging part of cricket breeding— maintaining stable nest conditions is essential for controlling hatching times. Most breeders recommend providing a tray of moist sand, vermiculite or peat moss as an egg laying facility— but I have often found this becomes too dry or too wet, mouldy, disturbed by the adults or contaminated with faecal matter. An alternative is a floral foam block as used by florists. Floral foam is available from craft stores in a standard block size measuring approximately 30cm x 10cm x 10cm. Place the block vertically on a small shallow tray. A reservoir to contain water should be made in the top of the block by cutting a shallow, funnel-shaped depression in it. Fill with water from above until it is saturated (this takes as much as 2 litres with a new block) and place the tray on the floor of the breeding enclosure. Moisture levels within the block can be measured by feeling the weight of the block—a light block suggests a dry Large scale cricket culture in an old chest freezer block. Its moisture content should be topped up as required. Female crickets will climb onto the block, force their ovipositors—or egg laying tubes—into the soft, moist foam and deposit their eggs within it. Once the block is riddled with egg laying holes, it can be removed and replaced with a fresh block. If left in for too long the crickets may burrow into the foam to consume the eggs. Some breeders make a wire fly mesh sleeve that fits over the block to stop this from happening. Floral foam used as egg laying media

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Female cricket inserting ovipositor into floral foam to deposit eggs

This cut away view of floral foam shows the depth of egg insertion by the female cricket D BROWN

The breeding colony should consist of approximately 200 adult crickets. Each week approximately 50 of these crickets should be replaced with the same number of younger crickets, two-thirds of adult size, to keep the culture young. Adult crickets will live and breed for approximately three weeks before dying. Dead crickets should be removed regularly to maintain hygiene. Simply shake all of the egg cartons onto the floor—sweeping faeces and bodies to one end—place them in a stack and then clean up the debris once the live crickets have moved back to the egg cartons. Egg laying blocks are placed in the breeding cabinet for three to seven days. Once the foam blocks become laden with eggs, they are placed into small plastic aquariums or plastic tubs heated to the same temperature as the adult enclosure. In a large-scale breeding set-up these hatching containers may be placed within the heated freezer on the ledge that houses the old freezer motor. The egg-laden foam block, an orange slice and tray of fish food flakes should be placed within these containers. Cricket eggs take approximately two weeks to hatch at 28°C. Newly hatched crickets, known as pinheads, will initially congregate near the foam block and use it as a valuable moisture source. The block may be left in place for that purpose—instead of an orange—or it can be dried and then reused for the next batch of eggs. Once pinheads are a couple of days old, add an egg carton lightly stuffed with tissue paper to the container for the crickets to move into. If the foam egg blocks are left in the breeding enclosure with the adult crickets for three to four days, all eggs should hatch within that time period. It is possible to have crickets available at any age, all of the time, by preparing a new container containing one or two blocks each week. The period from egg to adult usually takes between six and eight weeks at 28°C. However, remember not to overcrowd crickets, as they will eat each other in these circumstances. Newly hatched crickets (pinheads) emerging from the foam media

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D BROWN

If the number of crickets you breed exceeds your requirements, only leave the blocks in the breeding enclosure for 24–48 hours to reduce the numbers of eggs laid. Breeding on a smaller scale can be done in the same fashion—simply reduce the size of the containers and the number of crickets to comfortably fit the container. Smaller cultures are more stable when well insulated—place the entire tank or tub inside a polystyrene box or old EskyTM (unless this is being used as a breeding container) to achieve this.

Speckled Feeder Roaches (Woodies)— Nauphoeta cinerea

R PORTER

Unlike crickets, roaches thrive on neglect. The less you meddle with them, the better they breed. Place them in a 50–60 litre plastic tub with a well-sealed and The foam blocks are moved to a separate well-ventilated lid. You may also consider painting a container for hatching specialist substance on the upper inside edge of the tub as roaches can climb virtually any surface except Teflon® paint—marketed commercially as Fluon AD1®. A mesh lid, made by cutting out the middle section of a regular lid and replacing it with metal flyscreen, is required as roaches can sweat in enclosed boxes. Attach the flyscreen to the underside of the lid using a hot soldering iron to melt the wire mesh into the plastic lid. The temperature inside the culturing enclosure should be maintained at 28oC–30°C. Inside the tub, a number of hide sites will be required. Using the same method as for culturing crickets, place egg cartons vertically with the end section removed, allowing the roach faeces to fall on to the tub floor. Harvesting roaches is easy—remove one of the egg cartons and shake it into a container painted with Teflon® around its edges. Cleaning is simple when the hides are stacked in the above manner, as waste falls to the floor and the roaches generally reside inside the egg cartons. To clean, I recommend tipping the whole box on an angle so the faeces fall to one end. Let the roaches settle again before removing the waste. A dust face mask may be required when cleaning and harvesting roaches, as their faeces, bodily secretions and skin shed waste can induce quite significant hay fever symptoms. Hand washing after handling roaches is strongly recommended. Ideal food items for roaches include dry dog biscuits, chick starter crumbles, lucerne pellets and rat/mouse pellets. Roaches also require a source of moisture—orange and carrot may be used, but these spoil quickly and must be replaced regularly. Pumpkin is a better choice as it does not spoil as fast A basic roach culture. Note the Teflon® paint, Fluon-ADI®, around the perimeter

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and its tough skin holds it together. Some breeders use mealworms in the bottom of their roach cultures to clean up any spilled foods and to reduce waste build-up. Speckled feeder roaches are known as false ovoviviparous breeders—they retain their egg cases internally until they are ready to hatch. They then begin to lay the egg case, pausing for 20–40 nymphs to emerge. The life cycle of these roaches is quite fast—averaging 45 days from mating to nymph emergence. A female may have six broods per year, which usually completes her lifespan. Roaches may be harvested at any age and all life stages will live together amicably.

Locusts—Choroicetes terminifera Easy to breed, but tedious to feed, locusts should be maintained in a large, well-ventilated container at 28°C. A large tub placed standing on one end is ideal. The front end of this tub should be fitted with a flyscreen door in the same manner as fitting a mesh lid to a roach enclosure. The provision of a second small access door is necessary for feeding and maintenance. Upright twigs or plastic trellis mesh may also be provided for locusts to perch upon. Locusts are voracious feeders, which can make feeding time consuming. They prefer to eat grass, which yields the best results. However, consistent with their plague notoriety, they will eat almost anything. Cabbage, cauliflower, potato, celery, carrot, potato and tomato can all be used to supplement their diet but they should not comprise more than 25% of the diet. The provision of water is not necessary as it is obtained from food. The major difference between breeding crickets and locusts is the acceptance of nest sites by female locusts. Crickets will lay in anything. Locusts prefer to lay in containers with the entrance flush to the floor—they are often reluctant to climb up into a container. A lowered container can be provided in a number of ways. One method is to include a false floor in the container with several 5cm holes cut into it. The false floor should be spaced to ensure it is a perfect fit for either deep plastic containers or beer glasses. These sit immediately below the floor holes, filled to the brim with moist sand, providing the ground level laying sites. A laying depth of 10–15cm is preferred. An alternative is to mount deep takeaway containers into the floor. The first container is placed to block the hole and provide somewhere to seat the laying box. Another takeaway container of the exact same size is used as the laying container and simply sits inside the first container. Egg laying occurs when the female locust stands over the moist sand, burrows her abdomen downwards and deposits her eggs in layers within a foamy cluster—known as an ootheca. The egg clusters are often positioned against the edge of the container making them easy to observe. Each female may lay 30–60 eggs at a time—depending on her nutrition. Eggs take 10–15 days to hatch—the hatchlings should be housed in the same manner as the parents. A breeding population of 25–40 locusts, consisting of one-quarter males and three-quarters females, will generally suffice as a breeding colony. Males are usually brighter in colour and have larger feelers at the end of the abdomen. The growth rate of locusts is rapid—egg to adult takes 6–8 weeks. Some humans develop significant allergies to the proteins in locust shed skins—particularly when small fragments are aerosolised. If you are subject to allergic disease, wear a face mask at all times when working with locusts or avoid them entirely.

Bush Flies—Musca vetutissima The bush fly is a relatively low cost food item that may be fed as a maggot, live pupae, frozen pupae or as a fly. This particular species breeds very fast and is a secondary strike species—it does not require a meat-based diet for its development. It will readily accept artificial growth substrates as long as they meet moisture and nutrition requirements. page 77

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A simple fly breeding box—note the growing trays underneath and two substrate trays ready to insert

Inside a fly box—sugar bowl, pupae/fly bowl and substrate tray

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The bush fly is not difficult to breed. The offensive odours associated with maggots are limited, as rotting meat is not used in their production. Flies must be bred in a fly-proof box. These can be constructed from any material, although timber boxes usually experience the most stable temperatures. For a single colony, a box measuring approximately 40cm high x 30cm wide x 30cm deep is adequate. The provision of extra height will keep the flies away from the box door when open. The door should be positioned at the bottom front of the box and be of sufficient size to ensure the substrate container can be passed through it comfortably. A light bulb should be mounted near the top back wall—this will keep the flies up near the light and maintain heat without drying out the laying container. The use of two light bulbs can be an advantage in case one bulb fails during the night—this will also prevent the fly culture cooling. I recommend attaching lights to a basic probe thermostat set at 28°C or maintaining this temperature with an appropriately sized bulb for the box and the prevailing air temperature. In winter, a towel can be placed over the front of the box to retain heat. Three containers should be placed in the bottom of the box. These are containers for egg laying, a container of flies ready to hatch—a small quantity of maggots from every batch should be put in this container to maintain fly numbers—and a bowl of sugar or sugar cubes to act as a food source. Some keepers will place a sponge in a water bowl to provide moisture, others will spray the flies daily. The fly lays its eggs among the moist media

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The steps for fly production are quite basic and commence with obtaining a quantity of live pupae from a breeder or an insect supply company—500 pupae is recommended. The more flies you possess, the more fly eggs that will be laid and the more maggots produced. An insufficient number of maggots will not turn the egg laying mix over adequately, allowing it to dry, spoil or get mouldy. Once the flies have emerged, you are ready to start. Always ensure adequate sugar stocks are available or your flies will die after 24 hours. The key to successfully breeding flies is in providing the right egg laying mix. This may vary slightly in Each fly lays 20–30 eggs in a cluster. Freshly laid every culture, depending on local humidity, ambient eggs (right) and recently hatched eggs (left) temperature and substrate ingredients. Usually it is a matter of trial and error. The ingredients for the egg laying mix are as follows— • Bran or millrun—also named middlings in countries outside Australia. These are available from supermarkets and produce agents. • Water • Milk powder—provided as a source of protein and available from supermarkets and produce agents. The cheapest milk powder available is large bags of calf rearing powder. I recommend the following culture method— The finished product—a healthy bowl of 1. The appropriate mix is four parts bran or millrun—I maggots in a dry crumbly media prefer the latter which is nutritionally superior to bran with higher protein and an absence of calcium binding phytates—one part water and one part milk powder. The end product should be a moist, crumbly mix similar to wet and crumbled cake. It should slightly ooze milk when compressed. 2. Place a container, such as a deep takeaway container or lunchbox, filled with egg laying mix on the floor of the fly box. The flies should swarm to it fairly fast. 3. Wait 24 hours. At this stage you have two options. The first is to place a second container in, beside the first. Stir the first container and leave it in place for an additional 24–48 hours before removing it for harvesting. Put in a new container every 24 hours to ensure a continuous supply. Alternatively, you may wait another 24 hours and put in a second container. Remove the first container, tip it into a larger tub and place it somewhere warm to develop until harvest time. This second method is more time consuming but produces a better yield, as the flies can only lay their eggs in one tray—rather than spreading their eggs across the many trays that are left behind—but it provides less continuity of supply if the culture fails. The maggots are roughly the same size in each option at harvest time. 4. When appropriately sized maggots are noticed in the growing tray, commence harvesting by tipping the contents of the containers into a coarse sieve, such as a yabby sieve, to remove any big chunks of laying substrate. If the surfaces of the containers have developed a hard film, stir them. The remaining egg laying mix should now be of a consistency similar to slightly moist, page 79

dark coloured sawdust. If it is of a sloppy consistency, you are harvesting too early, the mix was too wet or there are insufficient numbers of maggots using the entire container. It will take 2–3 days to produce predominantly maggots. If you wish to produce pupae, it will take an extra two days. Production may be slower during cold temperatures. 5. Store the sieved produce in an ice cream bucket without a lid in a fridge. Maggots can be stored for approximately one week and pupae for four to six weeks.

Slaters Although these insects are simple to culture, they are uncommonly used in Australia. An initial culture of 40–50 slaters may be collected from a compost heap, beneath dried cow manure or under logs—they are more prevalent in urban areas than in undisturbed bushland. They may be kept in plastic tubs, although these tubs should be dark sided—slaters shun the light. The breeding container should be filled with moist peat moss substrate to a depth of 10cm and have a steady temperature of 28°C. A cardboard egg tray should be placed on the peat moss— the slaters will congregate and breed in this moss below the egg tray and on its underside. The moss should be kept moist with occasional water spraying. Slaters take approximately three weeks to hatch and between 4–8 weeks to mature. They may be shaken off the egg tray for harvesting. Suitable food items for slaters include carrot, banana skin and chick starter crumbles. The crumbles may be placed in a small bowl and carrot and banana skins placed on top of the egg carton.

‘Lesser Waxworms’ (Indian Meal Moths)—Plodia interpunctella The ‘lesser waxworms’ that are commercially available in Australia are actually the larvae of the Indian Meal Moth Plodia interpunctella—not the true lesser waxworm Achroea grisella. This is because true waxworm propagation is complex and grain moth propagation is easy. Meal moths should not be propagated at the same time as mealworms—you will succeed with meal moths but fail miserably with mealworms. Breed meal moths in a 20 litre plastic bucket or a large plastic tub with a lid fitted with mesh to allow for ventilation. The starter culture can be obtained from any mealworm breeder or within aviary seed hoppers. The pupae can be located in the thick weblike masses stuck to the surface or edges of the mealworm culture tubs. To commence culturing, an initial clump of webbing should be placed into the bucket or tub and onto a 10cm deep bed of millrun or bran. After approximately one week, moths will emerge. The moths will lay their eggs in the webbing strips along the top edge of the container where the lid meets the top of the bucket or tub. These egg strips are scraped off and spread among numerous cultures. The eggs hatch quickly when maintained at 28°C. Following hatching, small larvae will begin to congregate under the webbing shelters on the surface of the bran—you may also use an egg carton for this stage, as the larvae will create webs across the indentations on the carton. The webbing can be lifted off and the larvae harvested at any stage. Once the larvae mature they will seek out the edges of the container to create firm webbing cocoons. These cocoons can be opened to remove the pupae for feeding or used for subsequent cultures.

Fruit Fly/Vinegar Fly/Ferment Fly—Drosophila species Fruit fly cultures are not commercially available in Australia—only through university laboratories. However, the Drosophila species is common and can be found easily at the back of fruit shops smothering overripe waste fruit—take a few pieces home for a starter culture. The eggs are regularly laid in the cracks in the overripe fruit. page 80

DIETARY SUPPLEMENTS

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Fruit flies may be cultured in situ or as a separate culture. Simply place the rotten or overripe fruit in a bucket with a lid—which has a large hole cut in the centre—and the flies will inundate the fruit. The fly larvae grow in the bucket and will eventually crawl up the sides to pupate along the edge where the lid of the bucket meets the edge. These pupae should then be scraped off and placed in enclosures to hatch. Ideal fruits for the container include pineapple, stonefruits, citrus fruits, melon, grapes, pear, tomato and banana. Often greengrocers will allow you to take home boxes of waste fruits and may even set some aside each week to collect.

Fruit flies are attracted to, and breed

The use of dietary supplements is a controversial issue for in, fermenting fruits many keepers to consider. The basic types of supplements are calcium, vitamins and minerals and protein.

CALCIUM Calcium supplements are generally required if food items are low in calcium or high in phosphorus, if a reptile has a high demand for calcium due to its growth or breeding stage or if it does not use calcium efficiently due to a lack of exposure to UV-B light. Many dietary items are low in calcium—particularly live foods. Therefore, calcium supplements— available as powders or liquids—may be required. Powders are generally used with a live food diet and liquids with artificial diets, such as in meat or fruit and vegetable mixes. Calcium supplements are available in a range of chemical forms—calcium carbonate, calcium gluconate and dicalcium phosphate are the most common. There is little known about which supplement is the best in terms of bioavailability, or how well the body uses it. Some calcium supplements that include vitamin D3 should only be given to lizards with a potential vitamin D3 deficiency, such as those with no access to UV-B light. This will avoid vitamin D3 toxicosis—vitamin D3 supplements bypass the inbuilt mechanisms that usually protect against vitamin D3 toxicosis. The oversupply of calcium is less of a problem, as a lizard’s body has well-developed mechanisms to excrete excess calcium. The main issue with oversupply is that the body must be able to prepare for calcium metabolism. Generally, calcium is metabolised and used in the body through uptake in the stomach and bloodstream, bone storage or kidney regulation before being excreted via the gut and kidneys. A specimen constantly supplied with excessive calcium—i.e. high supplementation at every meal—will have activated the mechanisms for gut uptake and excretion but will store minimal calcium in its bones, as these mechanisms are essentially not switched on in the face of constant supply. If the specimen’s calcium needs suddenly increase— for instance during egg laying or with a sudden growth spurt—the ill-prepared body will exhibit symptoms of calcium deficiency despite the dietary supply. Calcium supplements can be provided in two out of three feeds or three out of five feeds. This will force the body to activate storage mechanisms on off days—allowing the lizard to prepare for instances of greater demand. Supplementation of live foods is generally achieved by either gut loading or dusting food items. page 81

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Gut Loading

Gut loading increases the calcium, vitamin and mineral content of a feeder insect by filling the insect’s gastrointestinal contents with a material designed to compensate for its nutritional shortfall. It is not designed to provide the insect itself with optimum nutrition—it is short-term and concerned with filling the gut immediately prior to feeding. Most insects die from toxic nutrient levels after several days of gut loading. Insects not immediately fed to specimens should be placed on a regular diet as soon as possible. Unfortunately, there are few commercial foods that are both an A suitable commercial insect adequate gut loading agent and an insect food in one—Passwell™ diet (Passwell Insect Booster™) Insect Booster may be the exception. Correctly designed diets developed solely on the basic requirements of the insect (i.e. feeding insect food rather than a gut loading product) will make them healthier live foods and will help to compensate for at least some of their nutritional downfalls. When using a commercial gut loading agent, it must be mixed well before use—different minerals often settle in transit and form layers within the container—remove other food sources and keep up the supply of water. Gut loading agents should be supplied for two to five days before feeding the insect to your reptile. When attempting to gut load small insects, such as pinhead crickets, the commercial food may need to be ground into finer particles. If a commercial gut loading product is not used, insects' nutrition can be improved in the shortterm by gut loading them with chick starter crumbles or vegetables high in calcium. Anecdotal evidence indicates that feeding foods to insects high in carotenes, such as carrot and capsicum, can improve the colour of the lizards that consume them.

Dusting

Good feeder insect nutrition will result in healthy insects

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Dusting involves coating an insect’s body with a powdered material designed to compensate for a nutritional shortfall. Most insects are covered with fine hairs that trap and retain these powdered products, which are then consumed. The major benefits of these powdered products are they can be used immediately before feeding and can be altered as required, depending on the individual being fed. The major disadvantage is that insects may groom the powdered

Properly dusted crickets

supplement off themselves—this is only an issue for a small portion of dusted insects, provided lizards feed as soon as the insects are supplied. If the dusting powders applied are somewhat heavy, it can affect palatability. The dusting should be heavy enough to fully colour the insect, but not to the extent the powder falls off it as the insect moves. Use a salt shaker to apply a surface coat of powder, then shake the insect around to allow any excess dust to fall off. Dusting can also be used on items such as pinkie mice, meat strips, minces, chicken necks and drumsticks. It is not uncommon for calcium and vitamin dusting supplements to be sold separately—in a mixed container, some of the chemical components of these concentrated forms interact and may be rendered inactive.

PROTEIN Protein supplements are generally available as commercial reptile supplements or insectivore supplements. These powdered products are designed to increase the overall nutritional content of fruit and vegetable mixes and meat or mince mixes. Their main disadvantage is that they are too coarse to use as dusting powders and should be mixed as recommended on the label. Be aware of how much you use—too much will make your mix dry and dusty and too little will make it sticky. Some people use these products as diets for insects such as crickets, slaters and cockroaches— they may act as a balanced high protein gut load. However, it is debatable whether a sufficient amount can be consumed to be of value. They will do no significant harm as a dietary supplement for insects and may improve growth rates.

FEEDING FACILITIES Different species should be offered their food items in different ways, which may also alter depending on the type of food being fed. Vertebrate prey items should generally be offered whole and placed on a shallow bowl to prevent any bodily juices from seeping into the substrate. A thin layer of water or petroleum jelly is recommended when providing fish and meat strips—they may stick to the bowl as they dry out in a heated enclosure. Invertebrates can be fed in several ways. Some keepers prefer to individually forcep feed. This is not essential but is a means of controlling food intake ensuring that each individual receives its fair share of food. It is most appropriate when feeding larger and active food items such as locusts, crickets and cockroaches. Insect items such as maggots, termites, slaters, small cockroaches and mealworms may be fed in a small, glazed, plastic or stainless steel bowl. Although the smooth surface should prevent escape, a thin layer of Teflon® paint can be smeared around the inside edge—preventing insects from colonising the enclosure. Mealworms in particular will burrow into the substrate, damaging eggs and biting sleeping lizards. Large amounts of escaped crickets and cockroaches will seek dark hides and may not be eaten. Larger insects, such as crickets and large cockroaches, may be supplied in a deep bowl lined with Teflon® paint or a thin layer of petroleum jelly to prevent escapes. It may be buried partially in the substrate to improve access—lizards prefer dropping into a container to feed, rather than climbing onto a bowl. Glass bowls should be avoided unless buried to the rim—many lizards will attempt to catch the insects through the glass walls. page 83

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A small amount of calcium or vitamin and mineral powder may be placed in the bottom of the bowl allowing the insect to dust itself. The fine powders will also assist in keeping the insects in the container, as it will adhere to their feet and impede adhesive properties. Releasing live insects directly into an enclosure is a common method for feeding crickets, cockroaches, locusts and wild fodder insects. The main concern with this is the risk of the insect colonising the enclosure. Simple and very stable live food and water containers For complex enclosures, I recommend bowl can be constructed using water pipe and takeaway feeding. Most species will consume live containers insects within a few hours of their liberation. If there is a possibility that insects may not be eaten, recapture them using a smooth sided glass container with a piece of carrot placed in the bottom. Slow release insect feeders are available commercially and can be made easily. These feeders contain gut loading or dusting powders that an insect must eat or crawl through before escaping from the container. They are useful for enclosures accommodating a single specimen, but may not be suitable for use among groups where a single specimen may dominate the feeder and consume Rhynchoedura ornatus consuming termites most of the escapees. Over time, the rate of insects escaping reduces dramatically—late feeders have less insects available. Insects lose their nutritional value the longer they stay in the container, therefore it is important not to leave the insects in there for too long. They are also more likely to die the longer they are forced to consume the powders within. Artificial diets are best fed using wide and flat dishes—ceramic or glazed pottery dishes are ideal as they allow unobstructed access to the food. Bowls should have flat bases to ensure they do not pivot or tip over when in use, and they should be rounded, as lizards have difficulty extracting food A Pygopus schraderi consuming a cricket from sharp corners. A small edge on the bowl will allow specimens to wipe the side of their mouth on a hard surface, forcing the food into their mouth. Bowls should be well sealed to allow for easy cleaning. Small terracotta dishes can be sealed by spraying them with a clear gloss estapol. Food bowls should be wide and stable to prevent spillage on to the substrate

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FEEDING PROBLEMS There are times in almost every keeper’s life when they are faced with an individual that is not eating. There are many different causes for specimens to lose their appetite including— Low temperature It is quite normal for lizards to stop eating as ambient temperatures start to drop. They will pick up on environmental cues that tell their biological clock winter is coming. As a result, many species will stop feeding and start to bed down for winter. This often comes as a rude shock to some keepers. It is normal behaviour and perfectly safe if the specimen is healthy in every other way. If it occurs, do not force it to eat—the food will not be digested and will sit and rot in the stomach. There is little to be gained by attempting to force an individual to reactivate—however, increasing ambient temperatures may stimulate an individual to re-emerge and recommence feeding. High temperatures Some lizards—particularly heat sensitive species—will cease feeding if ambient temperatures are too high. Heating loving species may become stressed in the absence of an appropriate heat gradient. This is particularly evident during summer when individuals seek out burrows or hides where cooler temperatures may be found. Incorrect food items Never assume that all lizards will eat all types of lizard foods. Occasionally, individuals—particularly new purchases and wild caught specimens—display food preferences. They may flatly refuse some foods or sizes, based on what they usually recognise as food. This problem is best tackled through trial and error and with information from previous keepers. Behavioural issues Dominance, stress, incompatibility and species tendencies, such as sulking Oedura filicipoda, can influence a specimen’s willingness to feed. In cases of aggression or dominance, remove the aggressive or dominant individual at feeding time to allow the subordinates to access food. This problem may worsen at certain times of the year, such as at breeding time when females may be wary to feed in the presence of males. Reproductive status Some lizards will cease feeding at breeding time. This may be due to physiological changes, which cause appetite suppression prior to egg laying, or may simply be a matter of abdominal space. Gravid females have much less abdominal space than non-gravid females, which reduces the available space for the stomach. As a result, some females will avoid eating large food items despite being perfectly normal sized items for that species. Gravid females should be offered food items of a size smaller than usual to ensure they maintain nutrition. Pain Any specimen suffering pain will often cease feeding. The pain may be short-term, such as a small flesh wound such as a bitten toe, or a more significant issue causing chronic pain, such as metabolic bone disease or arthritis. It can be hard to diagnose pain as a cause of the problem unless obvious injuries are present. Observing abnormal posture, such as sitting low on the hocks or moving sluggishly, may assist. Gastrointestinal disease Anything that causes the gut to function less than normally may reduce a reptile’s desire to eat. The most common problems in this category are gastrointestinal impaction and parasites. Gastrointestinal impactions are uncommon but can affect almost every group of lizards. They are indicated by weight loss, regurgitation, lack of faeces or faeces filled with sand. Individuals page 85

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with parasitic infections may initially eat more than usual until they weaken. With both problems, the sick individuals will lose weight and sometimes produce loose, unformed faeces. Veterinary attention is required if either issues are suspected.

TREATMENT Lizards that lose weight or refuse to voluntarily feed may require assist feeding, force feeding or tube feeding—

Assist Feeding

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A Lialis burtonis being assist fed a mouse tail

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The Lialis burtonis is then released to complete its meal

This feeding process describes any type of feeding where the food item is placed physically onto the individual’s nose to stimulate eating, known as teasing, or when it is placed directly into the mouth. Teasing is suitable for use with most individuals that will not readily flee or are not overly stressed by handling. It can be used with subordinate animals, when feeding new diets or with individuals suffering minor injuries—generally it will not work with sick individuals. To assist feed, repeatedly tap or wipe the individual on the nose with the food item until it stimulates a feeding response or an aggressive response—either way the specimen will open its mouth wide enough to put the food in. Alternatively, you may catch the individual and manipulate the food item into its mouth. Use gentle pressure at the sides of the mouth or gently prise the mouth open with the end of a plastic spoon and push the food into the gap that is available. To open the mouth, insert the tool into the side or corner of the mouth. Once the individual is biting down on the item, attempt to rotate it 90 degrees to hold the mouth open. This may require two people. Alternatively, for some species, squeeze the abdominal contents of a cricket into the space between the lips to stimulate licking or chewing. The rest of the cricket is likely to be eaten. All of these techniques rely on the individual completing the eating process, which is the safest way for beginners to approach assist feeding. Usually, once a specimen has a taste for The anatomy of the oral cavity of a Nephrurus amyae. The first rule of tube feeding is to avoid the glottis

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what is in its mouth and accepts it, it should swallow it. Avoid placing too many items or large items in the mouth at one time. Assist feeding can also be carried out using semi-solid or liquid foods. Simply place a small amount on an individual’s nose to be licked off or dip the nose in the solution and allow the individual to lap it up. Ideal foods for this include egg yolk, watered down protein supplements or diets for convalescent dogs and cats such as Hills a/d® prescription diet canned food.

Force Feeding

Tube Feeding

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This feeding process involves placing a food item into the mouth, physically pushing it past the tongue to ensure it enters the oesophagus. This should only be attempted by experienced keepers and on larger specimens only. The major risks are oesophageal injury if the keeper is too rough and suffocation if too large or too many items are placed in the oesophagus and regurgitated. Coating the food item very lightly with a slippery substance, such as raw egg, as a means of lubricating its passage, may assist. This feeding technique is stressful and should be reserved for specimens that do not Assist feeding a Nephrurus amyae voluntarily swallow with assist feeding.

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This feeding technique, one of last resort, involves using a crop gavage needle or rubber feeding tube—it can be dangerous if performed incorrectly. If a specimen is unwell enough to require this, then you should have already enlisted veterinary advice and been shown the appropriate technique. Species that consume small food items usually have little storage space in the front half of the gut, therefore feeding volumes are Force feeding a Nephrurus amyae minimal. Species that consume large items will have more room but less muscle tone— and will be at risk of regurgitation. Appropriate tube feeding products are limited to those that can be passed through a crop gavage needle or rubber feeding tube. Hills a/d® prescription diet canned food is recommended for carnivores, insectivores, omnivores and baby food purée for herbivores. Tube feeding a Nephrurus amyae. Placing the feeding tube to one side of the mouth is the safest approach

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BREEDING VISUAL SEXING The correct identification of gender is the first step towards breeding success. For many species, this process is simple—for others it requires educated guesswork. There are various methods of sexing geckos and pygopods, which range in complexity and reliability. Visual sexing is one of the most common methods and involves the examination of a gecko or pygopod’s secondary sexual characteristics including colour, size, pore structures, hemipenal bulges and paraclocal spur structures. Following is an outline of each method. For more specific details of distinguishing features in each species refer to the individual species chapters.

Colour Geckos and pygopods display little sexual dimorphism with regards to colour patterns.

Size

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There is minimal disparity in size between the sexes of many geckos and pygopods. Nephrurus geckos are the exception, with females generally the larger gender. During hatchling stage, there is generally no significant difference in the total length of the sexes, however hatchlings of the dominant sex may sometimes be bulkier.

Sexual dimorphism seen by size in Nephrurus amyae (female below)

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There are many other methods by which sex can be determined by size, depending on the species kept. Variations in the structural components of the body may be apparent when comparing two individuals with the same SVL. These variations usually appear as differences in the shape and size of the head and the overall build of the body but are usually absent or extremely subtle in this group.

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Many geckos and pygopods have pores on the underside Preanal and femoral pores in the Ringof their hind limbs and in the area in front of their vent. tailed Gecko Cyrtodactylus tuberculatus They are primarily used to produce chemical signals and, although the exact nature of the secretion is unknown, it is assumed to play a role in scent marking. Pores are described based on their location—femoral pores are found under surface of the thighs. Preanal pores are found in front of the vent. Some species may possess both types of pores while others will possess only one. In some species, the presence of femoral pores varies between individuals. Preanal and femoral pores are present in gecko species that lay hard shelled eggs including Dtellas, Gehyra, the Ring-tailed Gecko Cyrtodactylus tuberculatus and Heteronotia Preanal pores in Paradelma orientalis species. Pygopus and Paradelma species are the only pygopods that possess preanal pores, with the pores more distinct in males. As pygopods have no femoral regions, they possess no femoral pores.

Hemipenal Bulges

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A male reptile’s reproductive system includes paired tubular structures called hemipenes. Inverted in the base of the tail, they are everted from pockets in the tail base using pressure from fluid and through the relaxation of retractor muscles. Hemipenes vary in visibility, depending on the species. Hemipenes are obvious in adult males Generally, hemipenal bulges are visible in geckos but not of most species of geckos including Strophurus intermedius in pygopods. Hemipenes are easily visualised at breeding time as they literally hang down behind a gecko’s vent. However, the hemipenes of some Diplodactylus, Lucasium, Strophurus and Cyrtodactylus species appear to undergo seasonal reduction, making them difficult to observe in non-breeding individuals. Other sexual characteristics must be relied upon in this case. Seasonal reduction in hemipenal size may occur in some species making males appear similar to females. Note the paracloacal spurs which will always be larger in the male (below)

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Paracloacal spur in a male Strophurus ciliaris

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Paracloacal spur in a male Diplodactylus galeatus

Paracloacal spur in a male Oedura monilis

Paracloacal spur in a male Pygopus lepidopodus

Paracloacal Spur Structures These spur structures are found in a range of species in various forms. They generally appear as a pair of scale clusters, usually positioned slightly on the sides of the tail base, just behind the vent. The shape and arrangement of the cluster may be unique to an individual genus and species. Paracloacal spurs are always largest in males and are either smaller or completely absent in females. They are present in all gecko species with Lucasium and Diplodactylus species possessing the most variable and ornate spur clusters.   Pygopods possess paracloacal spurs that are largest in males and either small or absent in females. The Burton's Legless Lizard L. burtonis has the least well-developed spurs of all pygopod species.

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Positioning of the light source for the dorsal HTI technique

OTHER SEXING TECHNIQUES Hemipenal Popping

Positioning of the light source for the lateral (side-on) HTI technique

This method results in the external presentation of the internal hemipenal structures, which allow for sex to be determined. It is achieved by creating a build-up of pressure behind the structures. Manual pressure using the thumb or fingertips is used to overcome the retractor muscle and cause the hemipenes to swell with pressure and bulge through the cloacal opening. It is a reasonably reliable method for sexing geckos, although other methods are usually easier. Excessive pressure and/or repeated attempts can result in muscular bruising at the tail base, a crushing injury to the hemipenes or damage to the hemipenal blood supply and musculature. Geckos may autotomise their tails if the method is applied incorrectly. It is a technique best used when all other methods of determining sex are unavailable.

Hemipenal Transillumination (HTI) This is a technique adapted from a paper by Davis and Leavitt (2007). This sexing method can be used on adults and juveniles and does not require the specimens to be sexually mature. I have used it to sex more than 60 species of Australian lizards at various ages, including geckos. It involves shining a small, cool, bright light, through the tail base from the dorsal side of the specimen’s tail. This light will allow you to visualise the internal anatomy of the tail base. The hemipenes can be identified in males due to the hemipenes’ increased blood supply when compared to adjacent tissue, as well as increased tissue density in this area. They will either appear as red dots, red ovals or as a dull redness. The latter refers to the effect of increased blood supply, tissue density, degrees of shadowing and luminance creating an appearance of an overall red glow in the tail base. An absence of red structures and a general yellowish glow is observed in females. In some adults, the appearance of the hemipenes will vary with mood, body temperature and breeding season—it will also depend on factors such as seasonal hemipenal size, voluntary extrusion of hemipenes, tail position and hemipenal blood supply changes. The major limitations of this technique include the intensity of the light and the light’s penetration of tissue. page 91

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HTI technique on a typical juvenile female Oedura marmorata

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HTI technique on a typical juvenile male Oedura marmorata

HTI technique on a typical juvenile male Nephrurus gecko

HTI technique on a typical juvenile female Nephrurus gecko

The ideal candidates for this method are specimens with a dorso-ventral tail diameter of 8−10mm or smaller. Heavy dorsal pigmentation, heavy dorsal scalation, tails thicker than 8−10mm and handling difficulties may limit the effectiveness of this technique. However, modifications may assist in overcoming these issues. An alternative technique is viewing from the side, which requires placement of the light source against the side of the specimen’s tail. With species that have dorsal visualisation issues, males will generally exhibit the dull redness described earlier and females will display a clean yellow glow. I use three types of torches—an incandescent or halogen bulb producing a yellowish light, an LED torch producing a bright, white light and a fiberoptic otoscope as used for looking in the ears of dogs. The latter is rather good, as the light intensity is adjustable. However, it may not be readily available for private use—most veterinary surgeons will own one though. Be careful using intense light sources—these may also produce significant heat and may damage a specimen’s tail if it is left in position for a long period of time. This technique is suitable for use on juvenile geckos including Strophurus, Nephrurus, Underwoodisaurus and Oedura species that are sexable from 15mm SVL. The hemipenes will appear as red dots or short red ovals. Pygopods are difficult to sex in this manner due to their constant movement and overlapping scales. page 92

Under certain circumstances, males of some species will evert their hemipenes without intervention. This is rare in geckos and pygopods.

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Hemipenal Observation

BREEDING AGE The age at which individuals are capable of reproduction varies according to species, size and a specimen’s growth rate. Small species including Diplodactylus and Delma generally mature faster than others A Strophurus ciliaris with hemipenal eversion post mating and are capable of reproduction when they reach 60−70% of adult size which may occur at 9−12 months of age. Larger species including Saltuarius, Pseudothecadactylus and Oedura filicipoda may not reach 60−70% of adult size until they are 12−18 months of age, although it may take as long as 2−4 years.

Courtship among geckos and pygopods is not elaborate and best considered as mutual tolerance rather than a bonding experience. It involves the male chasing the female, rubbing her neck, biting or licking and eventual submission. In species including Pseudothecadactylus and Pygopus lepidopodus, mating may be quite aggressive, with the female often the primary aggressor.

S RANSOM

COURTSHIP

MATING S RANSOM

Following courtship, the male grips Mating behaviour in Nephrurus levis the female by the skin of her neck or shoulders with his mouth. He curls his tail base around to bring his hemipenes in contact with the female’s cloaca. Mating is brief and lasts less than 30 seconds. Mating usually occurs within hides, although some species may mate in the open. Nephrurus geckos may mate several times per day. Mating behaviour in Strophurus ciliaris

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STRATEGIES TO ENHANCE BREEDING SUCCESS COOLING Cooling is a process designed to mimic the natural physiological changes that reptiles undergo in the wild at the commencement of the autumn/winter period. Known as brumation, this period may be controlled among captive species through various husbandry methods and for various aims, including to encourage breeding success. Brumation is similar to the hibernation period seen in mammals. As the colder weather approaches, reptiles cannot raise their body temperature independently of the environmental conditions. Therefore, they seek a secure area, become lethargic  and cease eating. Tropical species may only reduce their intake of food at this time. Cooling is considered important in some species to stimulate egg production, known as oogenesis, and sperm production, known as spermatogenesis. The degree to which cooling is used as a reproductive strategy depends on the natural distribution of the species in question. Temperate species are naturally subjected to a greater degree of cooling—a drop usually more than 15oC—than tropical species for which a 5oC−10oC drop is adequate. Therefore, tropical species may respond to more subtle cooling cues than temperate species. Cooling does present some risks, despite being a natural process. Any reptile entering conditions of sub-optimal body temperatures also faces conditions of sub-optimal immune and digestive function. No specimen should be allowed to enter brumation if it is unhealthy. Specimens should also avoid entering brumation on a full stomach—food will not be digested during this period and will rot inside the stomach. As a reptile’s bodily functions are controlled by temperature, the need to feed is switched off during brumation—they require far less energy than usual to keep functioning at this time. Although there is much evidence to suggest that cooling is necessary for snakes, considerably less research has been carried out on the cooling requirements of lizards to achieve optimal breeding results. Many Australian lizard species appear to respond to variations in ambient temperature—others appear to respond to no cooling at all. However, reptiles are capable of responding to cues that we may be unaware of. Just because a thermometer indicates the basking site temperature is 45oC, reptiles may be aware of a 2oC−3oC drop in the heat gradient at the cool end of the enclosure. Reptiles also respond to changes in ambient humidity, barometric pressure, light cycles and food supply—which all signal the onset of cool weather. Cooling should be considered by keepers planning to breed. If you own a single lizard, juvenile or a group of lizards with no intention of breeding, cooling is optional, although environmental cues may induce brumation anyway—planned or not. This is perfectly healthy behaviour and should not be considered abnormal. If this occurs, you may modify your husbandry—particularly heat and lighting—to dissuade the initiation of brumation or, at the very least, expedite its completion. When practising cooling, consider your local climate and how it will influence what is required to actively cool your captive species. In some situations, no active interference is required for specimens to brumate.

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COOLING PROCEDURES DEPENDING ON THE SPECIES’ NATURAL ORIGINS AND CAPTIVE LOCATION SPECIES' NATURAL ORIGIN

SPECIES' CAPTIVE LOCALITY

COOLING PROCEDURE

Temperate

Temperate

Follow the natural weather conditions, allowing the temperature to drop by 10oC−15oC.

Temperate

Subtropical/tropical

Actively cool by ceasing all heating and moving the individuals to the coolest part of the house.

Subtropical

Temperate

Actively cool by ceasing heating or reducing ambient temperatures by 5oC−10oC.

Subtropical

Subtropical/tropical

Follow the natural weather conditions, allowing temperatures to drop by 5oC−10oC.

Temperate

Maintain heating throughout winter. Reduce ambient temperatures by 5oC overall or maintain lower temperatures as above. Continue to supply short active basking periods.

Subtropical/tropical

Follow the natural weather conditions, allowing individuals to cue off ambient signals such as humidity, air temperature, barometric pressure and light levels.

Tropical

Tropical

Brumation should not be initiated rapidly. It should commence with a gradual reduction in heat over a four to six week period. Either gradually dropping the ambient temperature or gradually reducing the number of heating hours can achieve this reduction. The brumation period typically lasts one to four months. Brumating specimens should be monitored for health issues every one to three weeks. They should have their health, body weight and overall appearance inspected with minimal disturbance. Particular attention should be paid to skin condition, eyes, oral secretions and breathing patterns. During a gecko and pygopod’s brumation period bacterial organisms are still active. This means that an infection can progress and the reptile cannot react to this appropriately. Ensure the enclosure does not develop a build up of faecal material and that it is not excessively dry or wet. The cessation of brumation should also be gradual. Increase temperatures by a few degrees each week or heating by a couple of hours each week until optimal conditions are achieved. Most specimens will begin to increase activity within a week or so of reaching these conditions, however they may take another week to return to normal feeding and behaviour. For at least the first month, feeding should occur more frequently than usual. page 95

SEPARATION In the wild, many species live quite solitary lives only coming together for breeding purposes, and others live communally throughout the year. In captivity, solitary individuals are often forced to live socially for our convenience. In the majority of cases, the specimens are none the worse for the experience but some species certainly do better on their own. Some keepers feel the need to remove males from females when not breeding. Whether this is necessary or not depends on the keeper and on the species involved. In some species, separation is required to avoid overt reproductive advances that may lead to aggression. In others, separation may lead to problems at the time when reintroduction is attempted. Pair separation is not essential for breeding success among geckos, and species may be maintained together throughout the year. Separation does not necessarily impact breeding, as many species are capable of spermatozoa storage between seasons. The separation and introduction of gecko species at precise times is used by some to control egg laying and hatching. This may be desired to fit their breeding season in around other commitments or to target particular markets—such as late season breeding to supply commercial facilities. However, there is little evidence to suggest separation is of any value among geckos if they are already tolerant of conspecifics at other times. Pygopods may need to be separated at times to avoid overt aggression. However, compatibility and tolerance is no guarantee of breeding success. In the Pygopus species, breeding males introduced short-term to females may be more successful than breeding established and compatible pairs. A rotation system of one week in, one week out—as used when breeding small pythons—should be considered if breeding success is limited in previously established pairs.

REPRODUCTION REPRODUCTIVE STRATEGIES Lizards produce hatchlings in two ways—by laying eggs or live bearing. All Australian gecko and pygopod species lay eggs. Some New Zealand gecko species are live bearers. Egg laying allows individual females to invest in smaller reproductive packages (eggs), more often, over a wider reproductive period. The eggs are left to hatch in an environment subject to climatic changes, pathogens, predators and natural disasters. Once hatched, the offspring that emerge are small, well developed and must fend for themselves as the maternal parent has usually moved away. Live bearing allows individual females to invest in larger reproductive packages, usually once a year during a certain period that enhances the offspring’s chances of survival. The mother selects where the offspring are to be born. They are initially protected by the mother and may be incorporated into a social group. Females can modify developmental temperatures by thermoregulating in sites that enhance appropriate body temperatures for development. The offspring produced are generally large and well developed at birth.

EGG TYPE All pygopods and most gecko species lay oval-shaped, soft-shelled, white eggs. Some geckos, including Christinus, Cyrtodactylus, Gehyra and Heteronotia lay round-shaped hard, calcified, white eggs.

CLUTCH SIZE A typical clutch for gecko and pygopods is one to two eggs. Most species lay two eggs per page 96

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clutch, although some Gehyra species only ever lay one egg per clutch. Species that generally lay two eggs may produce a single egg clutch if very young, very old or after producing numerous clutches in a single season.

BREEDING FREQUENCY A lizard’s size generally determines how frequently it breeds. The interval between clutches produced by smaller species is generally 2−3 weeks with more than seven clutches produced per year. Large species may produce clutches every 4−8 weeks resulting in more than five clutches per year.

GRAVIDITY

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Each group of lizards display different features when laden with eggs (gravid) or carrying young (pregnant). A gravid Nephrurus amyae displaying two A gecko will display noticeable abdominal visible eggs swelling when gravid. White, oval-shaped swellings may be visible through the abdominal wall but not in all species. These should not be confused with fat deposits, which are usually symmetrical and longer than an egg. Eggs are generally positioned sideby-side and asymmetrically with one egg usually slightly in front of the other. Eggs may be observed at any stage of the process, depending on the translucency of the female’s abdominal skin. Pygopod eggs are located one in front of each other, which results in a generalised swelling in the last third of the female’s body, excluding the tail. There are few reasons other than gravidity for swelling in this area, however swelling in this area may also be associated with recent feeding.

CARING FOR BREEDING FEMALE GECKOS AND PYGOPODS

A gravid Lialis burtonis displaying eggs in the caudal third of the body

Breeding can inflict a physical toll on females, regardless of the breeding method used. Other than self-inflicted hunger during courtship and occasional fighting injuries, stresses on male lizards at this time are energetically minimal. In comparison, females must produce eggs with sufficient nourishment to support developing young. Female geckos and pygopods often lay repeated clutches in a single season, having little time to recover between clutches. They will often noticeably lose weight prior to egg laying— particularly in the tail and over the hips. In most circumstances, condition should be regained within 7−10 days only to then be used for the next clutch of eggs that follow. This process places considerable stress upon a female. The drive to breed is generally stronger than commonsense page 97

and females may literally ‘lay themselves to death’ if sufficient nutritional support is not provided. Be aware of the following with egg laying females— • Egg laying is an innate response. Females will either lay when they are ready to—regardless of conditions—or not lay because conditions are unsuitable and specific cues are not met. • Each batch of eggs laid requires considerable ingredients in the form of fats and proteins— these must be provided through the breeding female’s nutrition, otherwise they will be drained from her stored resources. • If a female is unable to obtain sufficient nutrition, she will rarely stop producing eggs in response. In reality, she will continue to produce eggs to the detriment of her own health. • It is crucial to provide sufficient food in the first 3−4 days after the female lays her eggs and while the female is still producing early stage follicles and demands are at the lowest. Females should be fed ad lib at this stage. • Food should be provided in small amounts and often, as females have reduced available abdominal space while gravid. • Supplementary foods may provide additional nutrition after eggs are laid. These include pinkie mice, wingless roaches, small locusts, waxworms and silkworms. Although many of these food sources are high in fat, they are suitable at this stage, as large quantities of fats are required for the formation of egg yolk. • The supply of calcium to breeding females is very important. Among the species that lay hard shelled eggs, the need for calcium is much greater and they may actively seek powdered calcium supplements. Species that lay soft-shelled (technically termed ‘parchment shelled’) eggs still have a significant requirement for calcium for shell components. Calcium is also required for muscular function—in this case, the contraction of the uterine muscles. If a female’s calcium supply is limited, she will still attempt to deliver her eggs or young, and draw calcium from the blood stream and stored bone. If these stores are insufficient, uterine muscular contraction cannot be carried out and females will display signs of acute hypocalcaemia, such as weakness, limb paralysis, soft bones and seizures. This can be prevented through the consistent supply of calcium prior to breeding. (See The Use of Supplements on page 81.) • Nest site security is important to females. If a female feels a nest site is inappropriate, she may reject it and relocate. When a female is preparing to nest, it is best not to disturb her. Many species will dig a preliminary test nest in the days leading up to egg laying. Any disturbance at this stage may result in the female deeming the site unsuitable. • Many species will multi clutch in a single season. This continued breeding is a reflection of innate desire coupled with nutritional support and appropriate environmental cues—it need not be a concern. Suppressing reproduction can be difficult in some species—many store sperm—and removal of the male will not deter reproduction. Instead, other stimulating factors such as nutrition and environmental cues need addressing. Food supply and the temperature of the enclosure may need to be carefully reduced post egg laying. • Failure to lay eggs at the appropriate time will result in eggs being retained for variable periods. Among geckos and pygopods, retained eggs laid more than 10 days after their expected due date are unlikely to be viable. • If a gravid female gecko or pygopod dies, eggs may be successfully extracted from her uterus although with geckos and pygopods, these eggs are unlikely to be viable.

NEST FACILITIES In the wild, egg laying species seek areas where their eggs will be secure and can be maintained in suitable conditions to ensure their physical stability during the incubation period. Terrestrial page 98

species may lay their eggs in a moist pocket beneath debris, leaf litter, logs and rocks or in burrows. Arboreal species seek similar sites or use arboreal sites including termite nests, soft rotten wood material or pockets of moist fallen leaves found in tree hollows. These conditions should be mimicked in captivity to ensure reproductive females feel comfortable and secure enough to select the available sites, allowing them to produce healthy and viable eggs. More specific details of preferred nest facilities may be found in individual species chapters.

ARBOREAL SPECIES Most arboreal gecko and pygopod species will accept any dark, appropriately sized container featuring a suitable nesting substrate. Some prefer containers that are deeper than they are wide, while others have no preference. I recommend the use of opaque containers or clear containers that have been made opaque by painting them internally—in these, lizards will feel more secure and can nest when enclosures are fully lit, rather than wait until twilight or evening. The bottom of these containers may be left translucent to allow you to easily check for eggs by peering through the base. A suitable nesting container can be constructed from any moisture-proof container. Pot plants and their bases are suitable for geckos and pygopods, as well as takeaway containers, lunch boxes, water jugs with lids and plastic food containers. An ideal minimum container size is 1.5−2 SVL deep x 1−2 SVL wide. Extra space should be provided for bulky species or species with exceptionally long tails. This size will provide a lizard with ample room to dig, turn around and position itself for egg laying. Preferred nesting substrates include moist sand, peat moss, coir peat, a mix of coir peat and sand or sphagnum moss. Some breeders provide a layered container with a fine substrate, such as moist peat moss, on the bottom in a narrow layer and a coarser material, such as loose sphagnum moss, on top. The nesting substrate should be kept wet enough that it retains moisture for 5–7 days—so that you are not required to interfere with the nest site regularly. It should be loosely packed to ensure the egg laying female can easily push or dig her way into the substrate—it should not be so loose that it offers no burrowing support. Arboreal species prefer entrance holes placed on the top of the nesting container. The containers should be almost completely filled to the top, allowing just enough space for the female to rest comfortably on top of the substrate. Regardless of the container depth, most females will lay their eggs directly on the bottom of the container. Some arboreal species may also accept a moist area of floor substrate, as accepted by terrestrial species.

TERRESTRIAL SPECIES Terrestrial gecko and pygopod species tend to be fussier about their nesting sites, possibly because they would normally have more choice regarding the features of an egg laying site in the wild, such as soil texture, soil moisture, soil depth and orientation of the nest site. In captivity, suitable nesting sites are either a nest container that bears little resemblance to a natural nest site or a substrate of uniform consistency and limited depth. Thankfully, many terrestrial species are somewhat understanding of variation in nesting conditions if the nest sites are prepared appropriately and alternative sites are eliminated. Pygopods will nest in takeaway containers or small lunch boxes. If translucent, they should be partially buried in the substrate to render the lower section opaque. If opaque containers with clear lids are used, use them upside down and cut an entrance hole in what was previously the bottom—this set-up will have the benefits of an opaque container and make it easy to visualise the eggs through the clear base. page 99

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Nesting containers for terrestrial species should measure approximately 2−3 SVL long x 2 SVL wide x 0.5−1 SVL high. The entrance hole may be positioned on the side or on the top of the container. Terrestrial gecko species vary in their acceptance of facilities. Naturally burrowing species prefer natural nest sites and will generally be happy in any substrate they can dig a burrow Inverted plastic containers, painted internally to make them in. They will also use containers as opaque, make great terrestrial nest sites egg laying and hide sites. Small lunch boxes, takeaway containers or plastic food storage containers are suitable for these lizards. The container used should include an entrance hole placed no greater than chin height off the ground, as these species are generally less inclined to climb up into a nestbox. Alternatively, the container may be partially buried in the substrate so it can be accessed from ground level. Nonburrowing gecko species can be very fussy, as they like to lay their eggs beneath a flat surface. They often reject containers if they are too spacious. However, you can encourage container use among geckos by filling them very close to the top so the container lid becomes the surface under which they lay. The entrance hole should be positioned just under the lid edge. An alternative is to maintain a moist area beneath an upturned plastic or terracotta dish. This nest site should be prepared well before nesting is anticipated. Provide a corner of sand 1−2 SVL deep in the enclosure and moisten it a week before egg laying so that when laying is expected, the substrate is moist and crumbly and able to support a burrow. There are some keys to improving the acceptance of artificial nest sites among geckos and pygopods including— Appropriate depth Nesting substrate should be at least 1−2 SVL deep. If it is too shallow, the gecko or pygopod will reach the bottom of the enclosure prematurely and will continue to dig against the floor surface. Some females will exhaust themselves doing this and may reject that site and seek another. Appropriate substrate Consider the natural origin of the female when designing its nest site. Attempts to match a species to its innate substrate expectations can improve nesting outcomes. Appropriate moisture levels Most gecko and pygopod species lay their eggs in the area that provides the most suitable moisture, as substrate moisture provides an adhesive property to the soil, allowing burrows to be stable during egg laying. Retained moisture also prevents short and long-term drying of the eggs after they are laid. If there is no appropriately moist area and the females still attempt to lay their eggs, they will generally scatter them on the soil surface or bury them in a shallow burrow in the dry substrate. Appropriate security In the wild, eggs laid in excessively open sites or in the presence of predators will almost certainly not survive, therefore females prefer secure nesting sites. Similarly, a female lizard in captivity may seek a structure to lay her eggs against—such as the enclosure wall, under a feed dish or beneath the hide. If the only area of moisture or appropriate substrate is placed in the centre of the enclosure, the female may not deem it secure or suitable for nesting. It may also be of value to cover the enclosure front to increase privacy—if a female feels she is constantly being page 100

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watched, she may not nest. What is important is the female’s perception that the site is in some way protected. Appropriate environmental conditions Most geckos and pygopods require a stable and elevated temperature in order to achieve optimum embryonic development of their eggs. Therefore, many select nesting sites that receive direct, radiant or reflected heat from sunlight. It is important to place the moistened nesting substrate near some form of structure in an area that receives some direct radiant heat. This is more important with pygopods than geckos. Despite your best efforts, some females will consistently reject available nest sites, which may lead to reproductive disease.

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Female geckos and pygopods commence egg laying after digging a hole in the nesting substrate, generally close to the bottom of the enclosure or container. She will then turn around, reverse into the hole, lay her eggs and then backfill the hole with soil. Many females leave a depression in the top of the substrate, betraying the location of the eggs. Prior to egg laying, many species will perform test digs for several days. Female pygopods will A Saltuarius salebrosus laying use their heads to force their bodies deep into the nesting substrate, flexing sideways to widen the hole. If large chunks of material impede the passage of their heads, the females may grip the items with their mouth and pull them out. They will then create a small cavity at the end of the hole into which the eggs are laid. After laying, they will then reverse out of the hole and push the soil back in place with their head. Some species of geckos lay communally with dozens of eggs found in a single area. Whether this is due to a lack of suitable laying sites or a ‘safety in numbers’ strategy is not clear. Indentation in the nesting substrate is a sure sign

Collecting and Handling Reptile eggs differ from bird eggs in a number of ways. Bird eggs require regular rotation to disperse nutrients to the embryo and to ensure correct development, whereas reptile eggs do not require rotation. The embryo in bird eggs develops centrally, suspended in a membranous sac.

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EGG MANAGEMENT

Eggs are usually laid on or near the bottom of the container—Oedura marmorata

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Candling involves holding the egg over a cool, bright light

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Pink side up—the pink side represents the embryonic side. This should be placed upwards in the incubation container

The yellow side of the egg represents the yolk side. This should be placed downwards in the incubation container

The embryo in reptile eggs develops on top of a mound of yolky material from which it receives its nutrients. There is a common misconception that reptile eggs are delicate. It is actually quite difficult to damage a reptile egg—even during the first stages of incubation between 0−72 hours when embryos are small as embryonic location is dynamic. During this period, the embryo position will change if the egg is moved. During later stages—more than two weeks after incubation—blood vessels are well developed and rotation may cause embryos to hang sideways from their blood vessels or become crushed under the yolk body. There are two main methods for retrieving freshly laid eggs—the traditional method is to dig away the soil or substrate above the eggs and remove them singularly, being careful not to puncture the eggs as you dig to find them. It is often stated that if you employ this method, you must ensure the eggs are not tipped or tilted in any way. This is not necessarily correct. I recommend an alternative technique I have named ‘tip and realign’. To collect eggs from a container, simply tip the container into another bowl or tray. Spread the substrate so that it acts as a cushion for the eggs that follow—eggs are usually laid on the bottom of the container, therefore a good cushioning layer will be tipped into place before the eggs appear. If the eggs are laid in the substrate, the entire clutch may be scooped up and sorted out away from the enclosure. Over the past 25 years I have never associated a failed egg with the use of this method. Once the eggs have been tipped out, they need to be repositioned using candling. This involves the use of a bright, cool light source, such as a small incandescent torch or LED torch, to shine a light through the egg. While rotating the egg slowly and gently, two distinct sides should be visible—a clear side and a pink side. The clear side represents the yolk side of the egg and the pink side represents the embryonic side. The eggs should be positioned in the incubation container with the pink side facing upwards. Gecko eggs are among the hardest to candle, as substrate often adheres to them. However, they are easy to reposition thanks to their obvious blood vessels. Pygopod eggs are easy to candle and generally free from substrate.

Determining Egg Viability There is little benefit incubating eggs that have no likelihood of hatching. Therefore, it is important to be able to identify which eggs are viable—of adequate quality and fertility. Viability should be assessed pre-incubation—at the time of collection and post-incubation—for 10−20 days following incubation. page 102

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A healthy gecko egg (left) beside some firm, yellow ‘slugs’—Oedura monilis

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A dehydrated sunken egg. Note the clean white colour indicating an otherwise healthy egg

A piece of moist toilet tissue used to rehydrate a healthy sunken egg D BROWN

Pre-incubation indicators of non-viable eggs are— Yellowish coloured eggs Good quality eggs are generally a clean, white colour. Sunken eggs Particularly if other eggs in the clutch appear normal. Soft and squishy eggs Eggs that indent easily may indicate drying or nonviability. Firmness Viable eggs are generally plump and slightly compressible like a well inflated balloon. Eggs that are hard are often referred to as ‘slugs’ and are infertile non-viable eggs. Adherence of substrate While it may be quite normal for the eggs of some species to have substrate stuck to them, it should be consistent throughout the whole clutch. Different sized eggs in one clutch Significant differences in the size of eggs within a single clutch may indicate some eggs—generally the smaller ones—are non-viable. Sorting good eggs from bad is generally simple. However, if there is any doubt, suspect eggs should be incubated anyway. Equally, not every egg that appears viable will stay that way. Eggs that appear healthy initially may still fail if the embryo does not develop or dies. Most non-viable eggs that initially appear healthy will fail the first 7−14 days after incubation. Suspect eggs should be incubated away from viable eggs, as mould and bacterial growth may spread through substrate and affect healthy eggs. Post incubation indicators of non-viable eggs include— Failure to swell Most healthy eggs absorb water from the surroundings during the first 7−10 days of incubation. Failure to absorb water and swell may indicate embryonic failure. Hairy eggs Eggs that develop mould on the shell surface will generally fail. The mould may be light on the surface and green, pink or grey in colour or it may be a Size disparity and difference in substrate adherence in a clutch of Pseudothecadactylus lindneri

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A mouldy egg, in this case a dragon egg

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The fungal hyphae may extend a considerable distance into surrounding substrate

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Flies are often attracted to slimy eggs

full-blown mould forest that extends hyphae into the adjacent substrate. Mould growth is rarely associated with contaminated substrate. Cleaning the surface of an egg with 5% povidine iodine on a cotton bud may slow mould from growing on an otherwise healthy egg. Slimy eggs These eggs are generally associated with embryonic death and subsequent bacterial infection. They may also be eggs laid by females with uterine infections or by specimens that have retained eggs for excessive periods. Slimy eggs may attract flies into an incubation container, which may spread bacterial organisms to healthy eggs. Sunken eggs Eggs that shrink early during incubation are usually infertile or possess weak embryos that have died. Yellow eggs Eggs should retain a clear white colouration throughout incubation—even if covered in substrate. Failing eggs will often become dull yellow in colouration. There are several normal changes that occur in viable eggs post incubation that may sometimes concern keepers. These include— Windows These appear as dark patches on the surface of an eggshell, but are actually clear patches on a dark background. They signify areas of random decalcification in the outer shell and may appear at any stage during incubation. The shell membrane may become so clear that the embryo inside is visible. Windows do not indicate a problem with the egg or suggest any calcium metabolism issues. Hatchability is usually not affected. Depressions Eggs may occasionally develop dents or depressions in their surface. These may be caused by low humidity in an incubator, which occurs when there is excessive ventilation or the incubator lid is opened repeatedly. Sweating In the 24−36 hours prior to hatching, eggshell membranes become porous. Moisture or water vapour seeps from these pores as embryos transition from fluid breathing to air breathing and to potentially provide space for hatchling movement and activity. The porosity often appears as small beads of clear ‘sweat’ on the surface of the eggshell. This sweat often correlates with the incubation method used—in well sealed and A ‘window’ is visible centrally in the lower Strophurus egg

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closed incubation containers, sweating is the norm for geckos and pygopods. In poorly sealed containers or those opened regularly for inspection, sweating is not obligatory—this may be because the lower ambient humidity allows moisture to depart as vapour, rather than condensing as moisture. However, even under these conditions eggs may still sweat at times. The mechanism that induces sweating is poorly understood. Sweating at times other than during the immediate pre-hatching period is associated with increased embryonic mortality and can indicate inappropriate incubation conditions. Sweating may allow bacterial or fungal organisms to proliferate on the surface of the eggshell, as it provides ideal growth nutrients and media Normal pre-hatch sweating in a Strophurus because normal barriers and protective mechanisms taenicauda egg have broken down.

ARTIFICIAL INCUBATION Most incubation in captivity is carried out artificially using either homemade or commercial incubators. Successful incubation requires suitable incubation containers, a suitable incubation medium, heating, ventilation and a thermostat. Various options are explored below.

INCUBATION FACILITIES

W COSSELL

S RANSOM

An incubator is required to produce and maintain a specific temperature within a range of 1oC−2oC and to insulate eggs from temperature changes outside of the incubator. Many gecko and pygopod species will hatch just as successfully in a container located on the kitchen bench as they will in a purpose built incubator—the main compromise being the reliability and predicability of hatching.

A commercial poultry incubator—Hovabator™—being used for reptile eggs

A commercial poultry incubator—Brinsea Polyhatch™—being used for reptile eggs

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The design of an incubator can be as simple or as complex as desired. There are many commercial incubators available—however, few are designed specifically for reptiles and those that are, while efficient, can be very expensive. Despite this, they may be a wise investment when keeping species that require precisely controlled conditions. The remainder of commercial incubators have generally been designed for poultry and feature automatic turning and humidity control, which are of no value when incubating geckos and pygopods. Very simplistic models such as the HovaBator™, Brinsea Polyhatch™ and the Bellsouth 100™ are reliable and have produced results to rival more expensive models, although they are not precision instruments and their insulation features are imperfect—thankfully this is not necessary when insulating most gecko and pygopod eggs. An alternative to purchasing an incubator is to make your own. Suitable containers include melamine boxes with well-sealed lids, family-size Esky™ or cooler boxes and refrigerator bodies.

CONTAINERS  

D BROWN

The provision of containers in which gecko and pygopod eggs may be incubated is straightforward—the majority of species only require a well sealed container of adequate size and preferably transparent to allow you to observe activity without disturbing the eggs inside. Suitable plastic containers include takeaway containers, lunch boxes, freezer containers, rubber sealed ‘click-clack’ containers and sweater boxes. To some degree, container size depends on what will be placed inside it. Eggs should be spaced far enough apart to allow at least 0.5−1 egg width between them. This will in turn allow for up to 50% lateral expansion as incubation progresses and will also provide a safe distance between eggs in case an egg fails and becomes mouldy or slimy. Eggs located on the perimeter of the clutch should also have a space of at least one egg width around the outside of them to ensure they do not touch the container sides, which may encourage condensation to form on them. Small eggs or single clutches of small numbers of eggs may be incubated in small containers or as part of a group in a larger container. I recommend the use of a larger container, as they provide a much more stable incubation environment than small containers. The use of single containers to hatch multiple clutches of geckos and pygopods is fine, provided small species or large species are not placed together. The container should be filled to approximately 60−70% of its capacity with incubation medium. This allows for a good level of moisture in the medium and adequate air space above the eggs. Eggs should be laid on their sides and nestled in the medium to approximately their halfway mark—giving them 50% contact with the substrate and 50% contact with the humid air. They will also still be visible enough for you to determine egg health without picking them up. Incubation containers require ventilation. There are two primary methods of ventilating a container, depending on the types of eggs being incubated. Non-vented containers are suitable for small eggs. Simply make a single 2mm Strophurus taenicauda triaureus hatchling next to its partially buried sibling egg, yet to hatch

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hole in the container lid to provide airflow and maintain sufficient oxygenation in the container. Vented container lids are not typically used for gecko or pygopod eggs, but in other species they are used for large eggs or large clutches of medium sized eggs. You may provide extra holes in the lid or alternatively open the lid once a week to allow fresh air to enter the container.

HEATING

D BROWN

Incubators can be heated by two means— incandescent light bulbs or heat cord. Incandescent light bulbs are somewhat unreliable as they create hot spots around the immediate light area— however, a fan may negate this. Multiple bulb fittings are recommended in the event of one bulb failing, leaving the incubator without any heating. Much more efficient is the use of heat cord. This can the author’s incubator, showing the be easily set up and requires no electrical skills. The Inside heat cord and a 12V computer fan heat cord can be attached to the sides of the incubator using heat resistant tape—such as aluminium tape available from the suppliers of air-conditioning equipment—or using cable ties. It may alternatively be threaded backwards and forwards through a piece of welded mesh to create a heat panel that can be positioned against one wall or at the bottom of the incubator. Depending on the size of the incubator, the installation of fans may be required to circulate heat Basic 12V fans are easy to install and assist in and prevent areas from becoming overheated. Simple the maintenance of consistent temperatures 12V computer fans are ideal for this purpose and may be set up using a 12V transformer—your electrician should be able to inexpensively wire it up for you. Avoid installing a 240V computer fan—these generate a fair amount of heat and may make it difficult to control the temperature within the incubator.

TEMPERATURE CONTROL An incubator will require a thermostat to maintain the appropriate temperature for hatching. When using incandescent bulbs, a simple probe thermostat, on/off type thermostat or dimming thermostat is sufficient. The sensor of the thermostat should be positioned away from the heat source to ensure it measures the actual air temperature. I have found it useful to place the sensor inside a dummy container, such as an incubation container filled with dry medium to achieve this. Use of a dimming thermostat will lengthen the life of the light bulb in comparison to other types of thermostats. When using heat cord, a probe, on/off thermostat or dimming thermostat can be used, however a pulse proportional thermostat provides more precise control over temperatures in a smaller range as modifications to heat cord power supply are made more often than with other thermostats. Pulse proportional thermostats generally use less power, as they rarely force the heat cord to work at full power. page 107

Temperatures should be similar throughout an incubator. Multiple digital thermometer probes may help to achieve this, as they allow temperatures to be monitored at various sites. If significant differences are noted, they can be corrected by changing the direction of fans to move heat around. Alternatively, different incubation regimes may be utilised in different areas, taking advantage of higher temperatures on upper shelves.

INCUBATION MEDIUM

D BROWN

Incubation medium is the material or substrate into which gecko and pygopod eggs may be placed for hatching. It should be biochemically stable, well-aerated, sterile, and retain moisture without decomposition. Suitable incubation mediums include vermiculite, perlite, sphagnum moss, true peat moss, coir peat moss, sand and no substrate.

Vermiculite

This phyllosilicate basaltic mineral (hydrated phlogopite) expands to more than 10 times its size when heated, becomes exfoliated and is then referred to as vermiculite. It is used widely in the horticultural industry as a growth medium, a pool liner support and a fire retardant and insulator. It is available in numerous grades according to the diameter of the particles including 4−8mm or grade four (large), 2−4mm or grade three (medium), 1−2mm or grade two (fine) and 0.5−1mm or grade one (superfine). Standard, sealed incubation containers using vermiculite Grade three is the predominant form used when incubating gecko and pygopod eggs. Generally, the larger the grade, the less it compresses and the more stable the humidity trapped within the particle spaces becomes, providing more stable incubation conditions. The major advantages of vermiculite include that it is lightweight, soft, chemically inert and can hold many times its weight in water. It is the most popular incubation substrate.

Perlite This volcanic glass expands to 20 times its volume when rapidly heated to 1600oC. The rapid heating causes trapped water to vaporise and the glass to pop like popcorn—creating spaces caused by millions of tiny bubbles. This allows perlite to hold many times it weight in water. Being an aerated glass, it is harder and more abrasive than vermiculite, but is also much more stable. It is generally used in horticulture, particularly in the hydroponics industry. It is a popular incubation substrate, but used less often than vermiculite. Perlite is far more variable in its size and texture between batches than vermiculite, which may lead to problems during incubation if mixes are made too moist or too dry.

Sphagnum Moss This moss is a product of a bog or swamp plant in the genus Sphagnum, which comprises up to 350 species. These wetland plants are able to trap large amounts of moisture in their stems and page 108

leaves and can resist decomposition for a lengthy period of time. It is supplied bagged and semimoist or as a dried and compressed product in a bale. It is used in horticulture—often in hanging baskets for water-loving plants such as ferns. It is not generally used with geckos and pygopods other than with leaf-tailed geckos.

True Peat Moss This material is compacted and decomposed sphagnum moss and possesses many of the same qualities as sphagnum moss. As a fine and soft material it is often blended with other products for use as a water retainer in potting mixtures and seed raising mixes. It is somewhat acidic, which assists in inhibiting the growth of bacteria and fungi. When used in incubation containers, it is often combined in a 50:50 mix with sand or used on its own in a manner similar to sphagnum moss. When allowed to dry out, true peat moss becomes very dusty and can cause impactions when swallowed by hatchlings—mixing it with sand reduces this risk. This material is not popular—it can be difficult to maintain stable incubation levels, as the top layer dries fast.

Coir Peat Moss

Sand Red desert sand is used at times as an incubation substrate for desert species such as knobtail geckos species.

S EIPPER

This material is a by-product of the coconut industry and is comprised of finely chopped coconut fibre. Although it is quite water absorbent, it is not as absorbent as true peat moss and has a greater tendency to become dusty when dry. It is not commonly used in incubation.

No Substrate

N CRONIN/G MADDEN

Incubating eggs without any incubation medium or substrate is a recent trend among python breeders. Instead of using substrate, these breeders place the eggs on a grid or tray placed above a heated water bath, which provides stable humidity control. Facilities may A homemade no substrate incubation container with eggs be homemade or commercial, such as the Suspension Incubation Method (SIM) container manufactured by Squamata Concepts™. Although its use has been limited with lizards, it has been used successfully with some species of pygopods.

The SIM (Suspended Incubation Medium) Incubation container by Squamata Concepts™

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INCUBATION REGIMES There is really very little variation in the ways eggs are incubated across gecko and pygopod species. I recommend three basic incubation regimes— Standard incubation I incubate the majority of my gecko and pygopod eggs in a mix of water and vermiculite at a ratio of 1:1 by weight (e.g. 10g water mixed with 10g vermiculite) or 1:10 by volume (e.g. 10ml of water mixed with 100ml of vermiculite). Perlite can be substituted at the same ratio. A standard plastic container with a single 2mm ventilation hole is sufficient for most species. Hard shelled egg incubation Hard shelled eggs produced by species including Heteronotia, Cyrtodactylus, Gehyra and Christinus spp. should be incubated in a dry medium of water and vermiculite at a ratio of 1:3 by weight or 1:30 by volume in a standard incubation container. Heat sensitive species incubation The eggs laid by species of leaf-tailed geckos, including Saltuarius and Phyllurus species, should be incubated differently to the eggs of most other species. The incubation medium should be a standard mix of water and vermiculite at a ratio of 1:1 by weight or 1:10 by volume. Eggs should be incubated at room temperature, which should result in a daily temperature fluctuation of approximately 21oC−29oC. This peak temperature does not appear to cause any problems, as long as it is sustained for no more than a few hours. Some breeders use an incubator to achieve this variation, and set it up using a day/night thermostat to ensure the temperatures are variable. The hatchability and survival of hatchlings is much improved using this varied temperature regime, rather than a typical fixed incubation temperature.

TEMPERATURE DEPENDENT SEX DETERMINATION Among reptile families, the allocation of gender can be determined in two primary ways. One method is through Genotypic Sex Determination (GSD)—as with mammals. In this system, from the moment of fertilisation, the gender of the neonate is allocated as a male with the presence of two Z sex chromosomes (ZZ) or as a female with the presence of only one Z sex chromosome (ZW). The alternate method of gender allocation is Temperature Dependent Sex Determination (TSD). In this system, gender is modified according to the environmental temperature at a particular developmental stage in the embryo—usually in the middle third of the incubation period. There are many suggestions on how this mechanism has developed—generally it is believed that a particular temperature regime allows the embryo to develop into the gender that will be favoured by that immediate environment. Steroid hormones are considered the most likely mechanism that control TSD. An enzyme called aromatase is considered a particularly crucial factor in converting the male hormone testosterone into the female hormone oestradiol. It is thought the stimulation of this enzyme is a thermosensitive reaction—for example, different temperatures act as either a stimulant or inhibitor to enzyme activation, resulting in the conversion of male hormones to female or vice versa. Support for this theory is varied. The movement of eggs from a male-producing incubation temperature to a femaleproducing incubation temperature increases aromatase activity. Conversely, the movement of eggs from a female-producing incubation temperature to a male-producing incubation temperature gradually decreases aromatase activity. page 110

Among Leopard Geckos Eublepharis macularius, topical application of the oestrogen compound oestradiol benzoate to eggs in their second trimester and being incubated at exclusively male temperatures will result in femininisation of all embryos. Oestrogen is the physiological equivalent of a female-producing temperature and will override the effects of the male temperature. The overall pathway is a complex interaction between the enzyme levels, hormones and receptors and ultimately results in one gender being favoured and becoming the dominant genotype. The proposed pathway is simplified in the following diagram (Crews 1994): FERTILISATION TEMPERATURE INFLUENCES

ENZYMES HORMONES RECEPTORS

GONAD DETERMINING GENES

GONAD FORMATION

HORMONES

SEXUAL DIFFERENTIATION OF PHENOTYPE

There are three recognised patterns of TSD and considerable variation in the literature regarding the numbering and naming systems used. Type One Yields males at high temperatures and females at lower temperatures Type Two Yields females at high temperatures and males at lower temperatures Type Three Yields females at low and high temperatures and males (or a mix of males and females with a bias towards males) at intermediate temperatures. Type One TSD appears to be rarely used—only the New Zealand Tuatara Sphenedon and the Southern Water Skink Eulamprus tympanum are shown conclusively to use this regime. It has been suggested Ctenophorus species and gecko species including Oedura, Nephrurus and Strophurus may be Type One TSD but it is more likely they are Type Three TSD. Further study is required. Type Three TSD is more likely among geckos, as the average incubation temperature is much higher than the low level female-producing temperature, yet a mix of males and females—with a male bias—are produced. Type Two TSD is used by the Eastern Three-lined Skink Acritoscincus duppereyi and some Australian turtle species. Type Three TSD is proven in several dragon species and suspected in numerous gecko species although further study is needed. The temperatures at which these species are generally incubated tend to be in the non-biased range, resulting in both sexes being produced. Among Leopard Geckos Eublepharis macularius, which display Type Three TSD, females produced at higher temperatures are more aggressive and appear more masculine than females produced at cool temperatures. I am not aware of any Australian gecko species that utilise TSD and exhibit this behavioural modification. page 111

TYPES OF TEMPERATURE DEPENDENT SEX DETERMINATION IN GECKO SPECIES SEX ALLOCATION STRATEGY

MALE BIASING TEMPERATURES (Only Males Are Produced)

INTERMEDIATE (NON-BIASING) TEMPERATURES (Both Male And Female Are Produced)

FEMALE BIASING TEMPERATURES (Only Females Are Produced)

Type 3

−

26oC−28oC

< 24oC > 28oC????

Ocellated Velvet Gecko Oedura monilis

Type 1 or 3?

−

26oC−27oC?

< 25oC > ???

Northern Velvet Gecko Oedura castelnaui

Type 1 or 3?

−

26oC−27oC?

< 25oC > ???

Centralian Rough Knob- tailed Gecko Nephrurus amyae

Type 1 or 3?

−

25oC−29oC

< 25oC > ???

SPECIES

Strophurus species

Scientists are greatly concerned that global warming may influence the species that use TSD, resulting in species extinction through the predominance of one sex. Some people suggest dinosaurs were TSD and that climate change contributed to their extinction by this means.

NATURAL INCUBATION Some keepers allow their eggs to hatch naturally in the enclosure. Some consider this is a more rewarding experience and others prefer not to have to maintain an incubator. It is uncommon for an enclosure to be set up adequately that natural incubation will be as successful as artificial incubation. However, hatchlings can sometimes be achieved in outdoor or indoor naturalistic enclosures and with species that lay hard-shelled eggs. Geckos are one of the few groups that lay eggs that will hatch successfully in natural incubation conditions. Species that lay hard shelled eggs, such as Heteronotia, Cyrtodactylus, Gehyra and Christinus spp, will happily leave their eggs in the enclosure as they are somewhat resistant to desiccation. However, Gehyra and Cyrtodactylus species may eat their own young and eggs should be closely monitored for the arrival of hatchlings. The major difficulty associated with natural incubation is the provision of appropriate levels of humidity in an enclosure to prevent the eggs—particularly parchment-shelled eggs— from drying out, to prevent pathogen attack and to avoid predation of eggs and hatchlings by occupants and escaped food items—mealworms and Zophobas superworms are notorious egg feeders. Generally, the soil in an enclosure is not as sterile as the natural ground due to contamination by insect and lizard faeces and food scraps. Most natural incubation in captivity occurs by accident—the keeper was unaware of the clutch before it hatched. page 112

There are two successful methods used to hatch young incubated naturally if it is to be used as a regular hatching strategy. The first is to move the gravid animal to a ‘laying’ cage where all females are deposited to lay their eggs. All hatchlings will appear in one place and coexist only with other hatchlings. The alternate method is to allow the eggs to hatch in the parent’s enclosure and retrieve the hatchlings as they appear. Both of these methods have worked successfully. The keepers who have experienced the greatest success with natural incubation in enclosures are those that live in the same environment as the species.

HATCHLING CARE Reptile hatchlings are independent from their moment they leave the the egg. There are no convincing records of maternal care exhibited by egg laying geckos and pygopods. In the final 24 hours before hatching, young hatchlings internalise or reabsorb much of the remaining yolk material in the egg. This provides them with essential nutrition once they have hatched and will keep them full during their first 1−7 days, depending on the species. This will influence the appetite of the newly hatched reptile and will determine the willingness to consume the first meal. Some breeders recommend not feeding hatchlings during their first week outside of the egg. I recommend offering food 24−48 hours after removal from the hatching container, regardless of species. Initially 1−2 items should be offered and you should observe the hatchling to see if it eats them. Once an individual starts eating, you may increase the number of items fed. This method provides some backup if a hatchling was unable to resorb sufficient yolk for some reason.

FEEDING The size of food items must be reduced to suit the mouth size of a hatchling. In some species, this may mean reducing the available age class of an insect; in others it may require the change to an alternative food type. Large food items should be avoided—hatchlings’ digestive systems are not as well developed as those of adults. Hatchlings are also more prone to impactions from chitin when fed large meals of poor quality food items.

Feeding Frequency Hatchlings must achieve one goal—growth. To do this, food supply must meet day-to-day metabolic needs as well as provide increased protein levels for growth. The amount of food required and the frequency of feeding varies according to a hatchling’s metabolic rate. Many small geckos, such as Diplodactylus species, require daily feeding. Most other species should be fed every 24−48 hours.

Supplementation The provision of a suitable calcium supplement is very important during growth stages. This supplement should be supplied with two out of three feeds.

LIGHTING The provision of appropriate UV-B supplementation is essential for growth and calcium metabolism among all diurnal species. Additional, anecdotal evidence suggests that Strophurus and Cyrtodactylus hatchlings grow better when UV-B lighting is supplied. Alternatively, a supplement page 113

containing vitamin D3 may be used—this must not be supplied in excess, as the metabolic capabilities of hatchlings take time to fully mature and may result in over supplementation.

HOUSING In the wild, hatchling geckos and pygopods are prime food items. Therefore, they are often shy and prefer small enclosures where they may feel secure. The placement of a small hatchling into a large enclosure will make it reluctant to feed and result in it spending considerable time in its hide. However, species such as Strophurus geckos will be just as happy if a sprig of fine foliage is provided, among which they can perch and feel secure. Privacy is also important—during the first few months of life you may rarely observe some species. With this in mind, the regular removal of hides and the dislodging of occupants should be limited to when it is absolutely necessary. Physical interaction may be required only 1−2 times per week if food is being eaten and faeces are being produced.

HEATING One of the difficulties associated with raising hatchlings is heating them appropriately. Hatchlings are prone to overheating and dehydration. Excessively large enclosures should be avoided, as it is difficult to create an appropriate thermal gradient in them—particularly for diurnal species that require a heat lamp. Prior to use, hatchling enclosures should be tested to determine the most appropriate wattage heating. The use of a thermostat to avoid overheating may be warranted during hot temperatures. You should also be aware of the additions to ambient heat created by UV-B light sources.

COMPATIBILITY

D BROWN

Most gecko and pygopod species are passive and hatchlings can be raised in small groups. Occasionally problems may arise if there is a considerable size disparity between the smallest and largest specimens or if the enclosure is overcrowded. Dominant specimens growing faster than other siblings should be separated into groups of the same size to reduce aggressive behaviour. I recommend housing one species per container and—with large species such as cave geckos— one individual per container.

Nephrurus wheeleri

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COMMON DISEASES AND DISORDERS DISCLAIMER D BROWN

Although lizards are generally quite hardy by nature, they will occasionally become unwell or develop lesions—despite a keeper’s best intentions. This chapter will explore the common disorders that affect lizards, the associated clinical signs and treatment options. Most health issues require a degree of veterinary assistance, as many medications are available by prescription only. Therefore, a full physical examination of your lizard by a veterinarian is often required before medication can be prescribed. This is a legal requirement designed to establish proper drug use and slow the development of drug resistance caused by the inappropriate use of medication. Veterinarians who fail to meet these legal requirements may be fined and lose their practicing licence. Please do not ask your veterinarian to supply drugs without a prescription. The numerous medications discussed in this chapter are not for your own home treatment— my aim is to assist you if you ever seek advice from a non-reptile veterinarian who is unsure of the available treatment options. Many of the medications recommended here are rarely marketed Basic anatomy of a gecko, Nephrurus amyae for use with reptiles—they are often not registered as reptile medications and their recommended dosages have been developed using anecdotal evidence—not through official clinical trials conducted by drug companies. The medications recommended in this chapter are believed to be safe based on current evidence in veterinary literature. The following advice is not intended to be a substitute to veterinary care. Always follow the instructions provided by your veterinarian. Any recommendation in this text is to be used at your own risk.

NUTRITIONAL DISORDERS OBESITY Like in any species of animal, lack of activity coupled with excess nutrition can lead to obesity in lizards. In most cases, obese geckos and pygopods are quite obviously rotund, usually around the abdomen and tail base. Other specimens may store fat internally in large abdominal fat pads that may not seem obvious from the outside or may mimic gravidity. The major organ influenced by obesity is the liver. Fatty liver is usually a chronic disease and, on post mortem, the livers of these specimens are often bright yellow in colour and ooze fat when incised. Fatty livers and massive fat page 115

D BROWN

Hypocalcaemic paralyisis in a Diplodactylus galeatus hatchling

pads are quite prone to infection secondary to septicaemia—an infection in the blood stream— from infection elsewhere in the body and often respond poorly to medication. The most obesity prone gecko species is, by far, Pseudothecadactylus lindneri.

METABOLIC BONE DISEASE (Calcium/Vitamin D3 Deficiency)

This simplistic term encompasses a broad range of problems associated with insufficient dietary calcium and insufficient vitamin D3 production. This may be caused by insufficient UV-B exposure or dietary supply and/or increased calcium demand. The mechanisms of calcium metabolism are discussed under Ultraviolet B (UV-B) on page 56. There are several different scenarios under which metabolic done disease (MBD) is observed— early onset MBD, late onset MBD, delayed MBD and reproductive MBD.

Early Onset Metabolic Bone Disease

D BROWN

This disorder is associated directly with a lack of UV-B and/or a lack of calcium in new hatchlings. It may develop 7–10 days after hatching or earlier if the parents were also deficient in calcium and could not provide sufficient nutritional calcium in the egg. Individuals suffering from this disorder will display signs of weakness, fractured or weakened bones, twisted and deformed limbs and spines, twitching, seizures and anorexia associated with pain. Some symptoms are directly associated with damage to structural components, such as bone. Others are associated with the inability to supply physiological calcium, which results in hypocalcaemic seizures and weakness. A proportion of the individuals suffering seizures respond to improvements in the supply of calcium UV-B—little improvement will be noted if only one is supplied. Many will not respond adequately and will die—often after a seizure. Rapidly absorbed liquid oral calcium, such as calcium gluconate, may be Deformed fractured legs and shedding difficulties in a hatchling Pseudothecadactylus lindneri

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used—the dose is determined by how much can be safely consumed. Regular dosing (three to four times per day initially) may provide better outcomes.

Late Onset Metabolic Bone Disease This disorder occurs in lizards from one month old onwards. It results in specimens that initially appear to grow normally, however as the growth rate accelerates, problems arise. These problems may occur spontaneously or following a meal. Clinical signs are associated with the structural components of the body ‘collapsing’ under increased weight gain associated with growth. It may occur under two conditions—the insufficient supply of calcium or the oversupply of calcium, such as occurs with daily calcium supplementation. Basically, as the body grows, the calcium demand increases and calcium is either not available or, as a result of constant supply, the mechanisms required for calcium storage are not switched on. Lizards with this disorder will also suffer seizures, weakness and occasional spinal fractures. The latter occur when a full stomach places upward pressure on a weakened vertebral column, causing the vertebral bones to bend or break. It may result in paralysis. If the vertebral column is merely bent, digestion and subsequent reduced gut fill can sometimes result in recovery after a few hours. However, if digestion is delayed, the spine may become inflamed—resulting in partial paralysis that takes a few days to recover from. Failure to recover after this period usually indicates permanent spinal damage. Spinal injury at a young age may cause a lizard to have a weakened spine later in life. The largest, healthiest hatchlings in a group are most prone to these problems—they generally have fuller stomachs and a higher daily calcium intake than other hatchlings, as they feed on food items first. Recovery requires a combination of calcium supplementation and improved UV-B exposure, such as a couple of hours of direct morning sunlight. The size of food items should also be reduced for several weeks and these items should be fed in smaller quantities to reduce gut fill. I recommend providing calcium supplements in two out of three feeds or three out of five feeds. This will encourage the storage of calcium in the bones.

Delayed Metabolic Bone Disease This disorder is similar to late onset metabolic bone disease, although it occurs when juveniles are well past their growth period—often more than 12 months of age. It may cause spontaneous fractures to the spine or limbs, which are often secondary to minor trauma or following egg laying. Lizards suffering from this disorder may exhibit sudden paralysis, progressive tail or leg paralysis, suddenly deformed spines or rectal prolapse with limb weakness. They may also suffer functional gut obstruction due to the loss of nerve supply to the gut. These symptoms may occur secondary to a weakened skeleton, caused by having borderline metabolic bone disease as a juvenile, even though it may not have exhibited symptoms at a young age. Delayed metabolic bone disease will make a specimen weak and easily injured or damaged—particularly the vertebral bones. Delayed metabolic bone disease may be treated through the provision of calcium and UV-B supplements, coupled with strict rest to allow the weakened bones to heal. In the event of prolapses, surgery may be required. Spinal abnormalities may be healed by building up additional bone density following supplementation. This may result in a visible spinal lump, although over time the bone changes may be resorbed and the swelling reduces in size. Non-steroidal anti-inflammatories such as MeloxicamTM may be given to relieve pain in chronically affected older specimens. The dosage should be 0.4mg/kg once a day. Despite treatment, many lizards will develop long-term abnormalities of the spine and limbs. This is unusual in geckos but I have seen this manifestation of the disease in Strophurus ciliaris. page 117

D BROWN

Floppy Tail Syndrome

This disorder may be a form of late onset metabolic bone disease. In Australia it is recognised mostly in Pseudothecadactylus species and overseas in Uroplatus and Rhacodactylus geckos. Individuals suffering from this disorder display a floppy tail that appears unable to vertically support its own weight. When the lizard is positioned in a head down posture, the tail—rather than being directed upward—will fall downward and hang over the body at a 45−90 degree angle. A form of skeletal weakness may be responsible for this postural defect—specimens with floppy tail syndrome often have a small lump at the tail base that may support this theory. Other theories suggest that floppy tail syndrome is a muscular/ligament deformity caused by a lack of vertical opportunities during the hatchling period, which results in the tail An adult male Pseudothecadactylus lindneri base not being sufficiently developed to support suffering from floppy tail syndrome the weight of the tail. Lizards suffering from this syndrome display no other symptoms and the condition is not genetic. I have not personally observed a lizard suffering from this in any young I have bred— perhaps because they have ample climbing access and ample calcium supplementation as hatchlings.

Reproductive Metabolic Bone Disease

Although this disorder occurs in a number of situations, the most common form seen is observed in geckos that lay hard shelled eggs, particularly Cyrtodactylus sp. The calcium demands of these female geckos are significant compared to most other lizards and, unlike many lizards, they store calcium in calcium sacs in the neck or in the back of the throat. These stores can easily become depleted following repeated breeding and poor calcium supplementation. Despite this, the females will continue to breed, drawing their calcium requirements from their bones. This results in soft and rubbery bones that are prone to fractures—particularly when eating or digging nesting holes. Reproductive MBD can be treated through the supplementation of calcium. However, once clinical signs are evident, many females may be beyond help or have permanent deformities if they survive.

GUT IMPACTION A gut impaction is a result of indigestible material being unable to pass through the gastrointestinal tract. Indigestible material is generally inappropriate substrate material or poorly digested food items—particularly food with large amounts of chitin. Gut impaction may worsen when a lizard becomes dehydrated or in low temperatures—these both reduce the time it takes for food to transit through the gut. Gut impaction is an artificial syndrome. Australian species of lizards live in the wild alongside materials that cause impaction in captive bred lizards. Why then do they impact at all? In reality, it is actually quite uncommon, however it receives quite a bit of press as it is easily diagnosed page 118

or presumed as a cause of a lizard’s failure to eat and thrive. In my own collection of lizards, I have only observed three cases of impaction in 25 years and one of these occurred the day after purchase. It is generally more prevalent overseas, primarily because the use of inappropriate commercial substrates is very common overseas. The likelihood of impaction is affected by physical factors such as particle size, volume of material, the diameter of the intestinal tract and the type of material involved. Physiological factors such as dehydration, optimum body temperature and other health issues also play a role. Sand impaction occurs when a coarse grain sand substrate is used. It may be consumed by a lizard inadvertently while eating, such as through misdirected lunges for food, or from eating sticky foods on sand surfaces. Lizards do not usually eat sand willingly. Appropriately sized sand grains pose little problems to most adults, and particles of sand, small and smooth in diameter, will pass freely through the gut if the occasional item is consumed. However, as gut size decreases, the number of sand grains required to fill the gut cavity decreases. Therefore, I recommend the hatchlings of most species not be placed on sand of any kind. Generally, once a hatchling reaches 30−40% of their adult SVL, they can move onto sand—provided it is a species where this is recommended. The same rules apply with gravel—it is essentially just really big sand. Non-sand substrates such as bark, corn cob bedding and newspaper pellets may cause gut impaction, as they are all materials foreign to a reptile’s gut. They also have sharp edges and are generally larger than the average sand particle. Dietary impaction occurs when large amounts of poorly digestible foods are consumed or when inappropriately large-sized food items are fed to small specimens. Mealworms, Zophobas worms, large crickets and large amounts of rodent hair are particularly prone to causing impaction. The amount of chitin in a food item affects its risk of causing impaction. Chitin is the outer skin coating of insects and can be difficult to digest as it is thick and reinforced. When a large amount of chitin is present in the gut at a single time—such as a large meal of mealworms or abnormally large crickets—the body may find it hard to cope. The slowly digesting chitin builds up and is either passed out unchanged in the faeces or may reach a point in the gut where its passage is impeded by a natural narrowing in the intestinal tract. Physiological impaction occurs when gut movement slows or gastric emptying is impeded. Gut infection or irritation from parasites can slow gut function, a condition known as ileus. If food or other materials are allowed to build-up due to this slowed function, it may result in a gut impaction. If the gut passage of a dehydrated lizard becomes sluggish due to insufficient gastrointestinal moisture, the faecal material may dry and adhere to the gut mucosa. A build-up of urates in the cloaca of a dehydrated specimen may also impede the expulsion of faeces. Poor temperature control—be it too high or too low—will also influence gut transit times and may predispose an individual to impaction. Gut obstruction often appears clinically as a sudden blockage or as an insidious chronic problem such as is seen with a partial blockage. Individuals suffering gut impaction may display symptoms such as anorexia, lethargy, abdominal swelling, failure to pass faeces and weight loss. These are generalised symptoms and final diagnosis can only be made through an x-ray examination or by careful palpation of the faecal mass by your veterinarian. Treatment is sometimes difficult, as lizards are often presented too late in the progress of the disease when gut damage and critical weight loss may have already occurred. Dehydration must be corrected first—this is the most important step—as most lizards will have ceased drinking. In some cases, injected sterile electrolyte solutions may be required. In early cases, the provision of an increased amount of soluble fibre to basically envelope page 119

D BROWN

and carry the material out of the gut may help—particularly in cases of sand and food impaction. Suitable medications include various psyllium husk powders, such as MetamucilTM, designed as fibre supplements for humans. These should be mixed with water and provided orally. They can be repeated daily for one week or more—do not oversupply fibre or you may add to the blockage. Continuation of this method depends on whether the specimen is passing faeces or not. If no faeces are noticed after three days, do not continue with this method. Other materials that may have a laxative effect include indigestible oils such as paraffin and items that speed up This wild caught Nephrurus levis occidentalis died the rate of digestion, such as peanut butter. following impaction on its own shed skin when it Seek veterinary advice when these became dehydrated. Note the parasitic worms also methods fail to work or if the lizard is losing in the stomach weight. A veterinarian may be able to attempt an enema to help soften the impacted material. Surgically correcting gut impaction is unpredictable and best suited to large lizards—surgical interference with a gut small in diameter may result in strictures and gut problems that will lead to further impactions in the future.

PARASITIC DISORDERS INTERNAL PARASITES

D BROWN

Parasites can be directly transmitted through the consumption of infected faeces or indirectly transmitted through the consumption of an insect that has itself consumed infected faeces. Therefore, captive bred lizards housed indoors on a substrate that has not come from the wild should not suffer intestinal parasites, as these parasites will not spontaneously appear. However, if exposed to infected faeces repeatedly and for a period of time, these parasites may begin to harm an occupant. This is often made worse by unhygienic housing conditions, overcrowding and wet enclosure surfaces. Lizards housed in outdoor enclosures are more likely to be exposed to parasites. Wild caught animals will, almost without exception, have some degree of parasite burden. Spirometra tapeworm cyst (sparganum) after removal. Note further cysts in the adjacent skin in this Cyrtodactylus tuberculatus

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D BROWN T PORTAS

The most common parasites include worms, such as nematodes or tapeworms, and protozoa including coccidia and flagellate protozoa. In most cases, parasite burdens result in chronic weight loss and sometimes diarrhoea. Faecal testing is required to determine the presence of parasites. Microscopic examination of faeces can be carried out by your vet or can be learnt quite easily and performed at home. It can be useful to learn these techniques yourself which can save valuable treatment time by allowing correct treatment to be carried out early. Treatment can involve the use of medication. However, this medication should be targeted precisely at the parasite involved, which can only be determined through the analysis of faecal samples. Medication should be targeted in this way rather than by ‘shotgun’ medication. Microscopic diagnostics are a useful There are many commercial antiparasitic products health management tool available, but few are designed for reptiles. Each lizard group may vary in its reactions to medication—a safe drug in a dragon may potentially be toxic to a gecko and vice versa. Therefore, it is unsafe for me to record dose rates here. Consult your reptile veterinarian for their preferred medication regime. Treatment may also require de-stocking and decontamination to prevent reinfection—particularly with coccidial and pinworm infections. Image of Coccidial oocysts (400x) from Cyrtodactylus tuberculatus T PORTAS

EXTERNAL PARASITES

Ticks and mites are the two main external parasites occasionally found on lizards. Ticks are generally only found on specimens housed outdoors, although it is possible that tick larvae may be transported on leaf litter into an indoor enclosure. These large, blood-sucking parasites are more unsightly than dangerous. However, due to problems associated with the toxicity of acaricidal drugs, it is best to remove them as soon as they are observed. Simply grip the tick between your fingers, or with forceps, and employ Image of pinworm eggs (100x) from a twisting and pulling motion to remove them. Nephrurus asper Pathogenic mites are a limited problem to lizards. Although lizards may be inhabited by mite species, they are rarely infected by the snake mite Ophionyssus, although this has been observed on rare occasion on pygopods—particularly the Burton’s Legless Lizard Lialis burtonis. This could be because these lizards have a similar scale pattern to snakes. In the case of a non pathogenic mite infection, simple treatment methods include individually picking the mites off with forceps or smothering the mites with spray-on kitchen oils or petroleum jelly. Insecticidal treatment should be avoided with pygopods and geckos as they are able to lick their faces and consume the insecticide, often with fatal consequences. Consult your reptile veterinarian for appropriate dose rates. page 121

D BROWN

J VOS

Geckobia mites on a Saltuarius swaini

Geckobia mites on a Strophurus elderi

Non-pathogenic mites commonly affect geckos. These small, red mites target eye sockets, armpits and groin areas and are common when geckos arewild caught, housed outdoors or if an enclosure’s furnishings are sourced from where the mites naturally occur. There are many species of these mites and some are particular to certain types of geckos. They do no harm and may be removed using fine forceps or may be dabbed with vegetable oil to smother them. This smothering technique may need to be repeated at six weekly intervals for two or three applications. Generally, infections are self-limiting, as completion of their life cycle will not commonly occur in captivity. They do not usually survive long in an enclosure and are unlikely to reinfest lizards once the infection has been controlled. Freezing leaf litter in a sealed bag for two weeks can prevent the introduction of these mites.

SKIN DISORDERS DYSECDYSIS

R JACKSON

This disorder describes any type of skin problem that interferes with skin shedding. These types of problems usually reflect the overall health of an individual or environmental conditions. The provision of a moist hide area will usually encourage most species to shed correctly. However, if shedding problems are noted, pay attention to the tip of the tail, the toes and the eyes—the

Diplodactylus vittatus. Under normal circumstances, geckos and pygopods shed their skins as single pieces

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B MANNING

D BROWN

Shedding difficulties on the foot of a Nephrurus deleanii

Retained skin sheds on the head and forelimbs of a Pseudothecadactylus lindneri with metabolic bone disease

shed may be retained in these areas. If old skin is allowed to build-up around the toes, it may constrict the supply of blood to the feet, resulting in toe loss. This can be prevented with the gentle manual removal of retained skin. With generalised retained sheds, the individual should be placed in an appropriately sized container of moist sphagnum or moist peat moss overnight to soften the old skin and allow it to be shed.

SCALE ROT This term refers to a range of bacterial or fungal skin diseases of various causes and may also be referred to as blister disease. It may be the result of wet and unhygienic conditions—particularly affecting arid zone species—or it may be secondary to trauma. It affects all types of lizards, but occurs least frequently in geckos. It sometimes develops in winter-cooled reptiles while their immune system is inactive and will flare up when the specimen is brought back into warm conditions. It is one of the most common forms of post-cooling infection and may result in sudden death. Scale rot generally first appears in areas as reddish brown or yellow swellings, often located on the underside of a lizard’s belly or feet. Later, as these scabs lift, wounds appear as red and ulcerated areas. These lesions can spread rapidly and, in the case of bacterial infection, can lead to septicaemia and sudden death. Treatment can be successful when initiated early and involves improvements to the husbandry conditions, increasing the temperature slowly if the lizard has cooled and starting to treat the infection involved. It can be helpful to culture the bacterial organism or fungal organisms involved. A common bacterial isolate is the multi-resistant bacteria Pseudomonas and Aeromonas. A common fungal isolate is Dermatophilus. Culture should be carried out before any medications are applied—the wrong medication may worsen the condition. Minor bacterial infections can often be treated through the removal of necrotic material, cleaning of the wound with an iodine-based disinfectant and then coating it with an antibiotic ointment containing silver sulphadiazine. If it has not improved somewhat within three to five days, then oral or injectable antibiotics should be prescribed according to the culture results. With more serious infections, your veterinarian may prescribe a presumptive antibiotic or antifungal while awaiting the culture results. Scale rot can spread to other lizards in a group through contaminated substrate. Therefore, infected specimens should be separated and treated individually. They should be placed on an easily replaced surface such as butcher’s paper or paper towel during the treatment period. page 123

NAIL, TOE AND LIMB DISORDERS In addition to the problems associated with dysecdysis, there are several other disorders that may affect nails, toes and limbs. Overgrown nails are quite uncommon in geckos but may be caused by insufficient nail wear. Nails often become curved and distorted and may distort the toes and cause chronic osteoarthritis due to abnormal joint wear. Trimming them can be difficult, as the blood vessel within the nails often grows longer than normal and may bleed when cut. It is best to have some Condy’s crystals (potassium permanganate) nearby to apply to the nail if it bleeds. Simply dip a cotton bud in water, dip it into the crystals and dab the crystals onto the nail tip to stop the bleeding. Other limb problems include trauma, chronic malformation associated with metabolic bone disease or fractures. These can result in uneven posturing and lead to chronic osteoarthritis. Minor trauma to the skin can cause infections in the bone and joints. Chronic kidney disease may result in limb problems caused by articular gout—uric acid deposits in the joint spaces.

S EIPPER

EYE DISORDERS EYE TRAUMA

This can be caused by cage mate aggression, abrasions from harsh enclosure furniture and injury from prey items—such as scratches from large insects including cockroaches and locusts. With any eye injury it is essential to assess the depth and location of the injury—is it associated with the lid, mucous membrane or corneal surface? If associated with the cornea, is it superficial or deep? Injuries to the eyelid or mucous membrane are usually simple to treat and may not require antibiotics—however, an anti-inflammatory might help. Suspected corneal injuries should be assessed by a veterinarian—incorrect management can result in the loss of vision or loss of the eye. Geckos and Crenadactylus ocellatus horni . The ability of geckos pygopods develop eye issues far less frequently and pygopods to lick their eyes makes them less than other lizards. I suspect their ability to lick prone to eye disease complications and clean their eyes reduces the development and progression of clinical disease, keeping them clean, moist and free from debris.

PHOTO-KERATOCONJUNCTIVITIS If eye damage is occurring in multiple lizards or in single lizards associated with the recent replacement of UV-B emitting compact lamps or high intensity bulbs, then photokeratoconjunctivitis should be considered. Recorded cases have specifically been associated with the inappropriate use of a phosphor compound in a specific range of bulbs. However, the incorrect use of other bulb types as dual purpose UV-B may be a factor—it may bring individuals too close to UV-B sources. An individual suffering from photo-keratoconjunctivitis will usually display painful and puffy eyes, lethargy, lack of appetite and skin damage. The eye damage experienced is equivalent to page 124

snow blindness or ‘arc welders flash’ and is caused by damage to the corneal, or eye surface, and the conjunctiva, or lining of the eyes. It does not cause complete blindness, as it does not affect the deeper parts of the eye. Affected individuals generally recover between two and 14 days once the offending lamps are removed. Medication is only required if the skin of the eyelid becomes infected. As most geckos do not naturally expose themselves to high doses of UV-B light, they possess limited protection from overexposure and are particularly at risk, particularly if they are exposed to compact UV-B globes in reflectors placed at close quarters.

PRIMARY BACTERIAL EYE INFECTIONS These infections are uncommon but may occur in the event of poor hygiene, the contamination of the eye with faecal matter or biofilm or the bacterial contamination of water used to mist enclosures. When signs of trauma are absent, primary bacterial infections should be considered. They should be treated aggressively by your veterinarian.

RESPIRATORY DISORDERS The respiratory tract of a reptile is primitive and easy to damage. Therefore, problems affecting the respiratory tract in lizards are generally rather significant. Unlike mammals that possess complex lungs, reptiles basically have large inflatable bags for lungs. If an infection or inflammation becomes established within one part of these lungs, it may affect the entire lung. Coupled with the production of solid pus, it means respiratory problems may be difficult to treat. Respiratory infections are generally associated with bacterial infections, a vitamin A deficiency, environmental husbandry problems and parasites. Individuals suffering from a respiratory disorder display symptoms including frequent sneezing, audible or laboured breathing, slight mouth gaping, mucous discharge from the mouth and nose and open-mouthed breathing.

BACTERIAL PNEUMONIA Bacterial problems are most commonly associated with septicaemia—a blood infection—spread from infections elsewhere. Bacterial infections may also spread from oral problems or they may occur with immune suppression caused by secondary vitamin deficiencies or environmental problems. They are often end-stage problems observed in critical cases. Treatment involves culturing the organism involved and administering appropriate systemic antibiotics.

VITAMIN A DEFICIENCY This respiratory disorder is often observed among lizards fed poor quality food, such as insectivores fed poor quality insects or herbivores fed poor quality vegetables. It is not common because most keepers provide a vitamin supplement with these foods. When it does occur, it causes a lizard’s healthy lung and upper respiratory tract tissue to thicken and sustain damage due to a change referred to as squamous metaplasia. Vitamin A deficiency causes the surface cells to change from cells that are actively able to move debris from the surface—via little hairs on the cell surface known as cilia—into flat layered cells with limited or no functional clearance abilities. Therefore, they are more prone to the build-up of mucous and debris and to infection.

HUMIDITY RELATED PROBLEMS These respiratory problems relate to changes in humidity. In particular, when arid zone species, which have adapted to breathe low humidity air, are exposed to high humidity air, their lung tissue must change to cope with this. The lung tissue will usually increase the production of page 125

mucous to cope with the moisture-laden air and its associated dust, debris and micro-organisms. However, as these species are not accustomed to clearing this amount of mucous from their lungs and upper respiratory tract, it may result in respiratory dysfunction, leaving the lungs prone to secondary infections. Humidity related disorders can be avoided by maintaining these species in hot and dry environments with low humidity. If nasal discharge or oral mucous is noted in these species, this can help to improve or reverse clinical signs. If it does not, seek veterinary advice.

PARASITIC PNEUMONIA The recent introduction of legally wild caught lizards from Western Australia into captive populations has been associated with an increase in the recognition of disease associated with respiratory parasites. These parasites do little damage when present in small numbers and their life cycles are such that they do not proliferate in captive situations. However, they do cause problems when they die naturally or when prophylactic worming medication kills them. The lizard then has to deal with a dead parasite in their lung tissue. Many will cope well with this, but in others it may lead to secondary inflammation or infections. In many cases, there is little that can be done to prevent this. High humidity may complicate the problem.

TRAUMA BITE INJURIES

D BROWN

Bite wounds can be severe at times, depending on the type of lizard. Bite injuries are most commonly found around the face and limbs of a specimen and on the front feet. They are associated with incompatibilities in relationships or from misdirected feeding responses. Wounds of a minor nature should be cleaned with an iodine-based disinfectant and treated topically with an antibiotic ointment such as a silver sulphadiazine cream. Larger and more swollen wounds will require additional care by a veterinarian who can prescribe medication. Pain can be quite significant and lizards may be provided with pain relief in the form of oral MeloxicamTM at 0.4mg/kg. Oral or injectable antibiotics may be prescribed for use systemically, often in combination with a topical product. Topical ointments must be water soluble and non-greasy, such as silver sulphadiazine or silver sulphadiazine/enrofloxacin ointment. These are all prescription drugs and will require a consultation to obtain them from your veterinarian. Occasionally, surface wounds may heal adequately but abscesses may develop under the skin. These appear as firm lumps or holes where abscesses have ruptured. Reptiles produce solid pus, not liquid as in mammals—this makes these lumps quite hard on palpation and means that drainage of the abscess is not likely. Instead, your veterinarian may open the abscess, remove the solid pus material and flush the wound clean. Systemic antibiotics are often required. Bite trauma on the tail of a hatchling Strophurus taenicauda triaureus inflicted by a cricket

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THERMAL BURNS Burns are generally the result of lizards coming too close to heating elements and not moving away fast enough. This occurs most commonly when an occupant sleeps on a cold light fitting or heating element while it is switched off and when it turns on and heats up quickly, the cold reptile cannot get away fast enough—this may result in burns to the abdomen and limbs. Burns may also occur if heat lamps are placed too close to the substrate. Lizards are slow to respond when initially cold and will not realise they are in the beam of a hot lamp until the remainder of their body heats up—by this time the damage has been done. Although thermal burns initially resemble scale rot, they are generally more defined and larger in size. They are also painful. It may take some time to appreciate the extent of full thickness burns—when the scab eventually lifts off it may reveal a surprisingly large area of scale loss and exposed underlying tissue. Substantial burns must be treated aggressively to prevent infection—seek veterinary attention. An appropriate antibiotic ointment will need to be applied daily along with an adherent dressing to keep the wound clean—try FixomulTM. Large burn wounds may require six to eight weeks of intensive treatment to achieve adequate healing. Healed burn wounds often loose their pigmentation and scale patterns.

REPRODUCTIVE DISORDERS PRE-OVULATORY AND POST-OVULATORY STASIS (EGG BINDING OR DYSTOCIA) Pre-ovulatory stasis refers to reproductive disease that occurs before the eggs are fully formed. Post-ovulatory stasis refers to reproductive disease that occurs after the eggs are fully formed. Most reproductive ovulatory diseases are associated with poor husbandry including malnutrition, inadequate nesting sites, inappropriate temperatures, inappropriate humidity or the absence of UV-A or UV-B light. Other factors such as premature breeding, also influence preovulatory stasis. Pre-ovulatory stasis is considered to have occurred if the initial formation of the egg has been disrupted at any stage. This may be due to injuries inflicted by harsh palpation, infection, inadequate serum calcium to allow shell formation, insufficient UV-B resulting in insufficient calcium supply and any environmental factor, such as heat or humidity, that delays follicular development. An understanding of normal follicle development makes it easier to understand the mechanisms of failure. Oestrogen from the ovaries stimulates the liver to convert body and dietary fats into vitellogenin, which is then absorbed from the blood stream by the follicles to form yolk. During this stage, the yolking follicles swell up to 100 times their normal size and the liver enlarges dramatically, often becoming yellowish in colour from the absorbed fats. Large amounts of calcium—required for later shell development and by neonatal lizards—are added to the follicles. A follicle becomes an egg after albumin is deposited around it and a shell is formed. It can be difficult to distinguish between normal vitellogenesis and pre-ovulatory stasis, as the latter is simply a failure to progress further. The major difference is that females suffering preovulatory stasis are often lethargic, unresponsive, experience weight loss and remain ‘gravid’ for far longer than normal. Females suffering pre-ovulatory stasis do not generally attempt nesting behaviour. X-rays or an ultrasound may be used to determine if the body is filled with shelled or unshelled page 127

eggs. In pre-ovulatory stasis, the visible eggs are rounder in appearance. Post-ovulatory, the eggs appear oval-shaped. Treatment for pre-ovulatory stasis involves the correction of any husbandry conditions that may have caused the problem. If this fails and the female does not reabsorb the yolk material, surgery will be required to save her. If treatment is not initiated promptly, the yolks may become septic, the uterus may rupture or the yolk material may coalesce into a hard fibrous mass. Surgery is needed to save the lizard’s life but this will also desex the female, removing her subsequent ability to breed. Understanding the correct inter-clutch interval for a species may help in predicting expected laying times. Post-ovulatory stasis refers to any situation when a shelled egg is unable to be passed, and is far more common than pre-ovulatory stasis. It may be caused by a problem with the egg itself— such as malposition or malformation of an egg or the rupture of an egg or oviduct—or it may be due to physical problems such as pelvic injuries, pain, abdominal masses or uterine damage. More commonly, slow or difficult labours (dystocias) experienced by lizards are associated with husbandry problems such as low temperatures, interference with the nesting female or inappropriate nest sites—the latter being the most common and usually occurring in combination with other factors. Dystocias are far more common in dragons and monitors than in skinks, pygopods or geckos—the latter are more inclined to drop their eggs regardless of conditions. It is possible for a female lizard to initiate the laying sequence, only to find the conditions are unsuitable. These unsuitable factors include dry substrates, cold enclosures, interference from people or other lizards, pain or physical inability caused by metabolic bone disease. Subsequently she will cease the laying process. Some females may restart laying if the appropriate conditions are met—others may stop altogether. There are three options I use for dealing with dystocias—wait and see, medicate or wait and medicate. Wait and See Some species will happily progress with a full belly of eggs and restart the laying process after a short break. There is no reason why these eggs will not normally be viable. The wait and see approach is appropriate for managing dystocias provided the lizard’s body weight and appetite is maintained. Risks include uterine infection and exhaustion if there is any degree of delay in egg laying. The outcome is generally unpredictable. Medicate In mammals, a hormone called oxytocin stimulates uterine contraction. In lizards, a different hormone called arginine vasotocin is used. It is vaguely similar to oxytocin, but not available commercially—therefore, oxytocin must be used when medical intervention is required to manage dystocia. The dosage administered must be very high—1−6 IU/100g bodyweight—as lizards only respond partly to oxytocin. Many non-reptile veterinarians are unaware of the need to administer such a high dose rate, therefore it is not uncommon for this treatment to fail badly when administered at dog/cat dose rates. In my experience, oxytocin be administered along with injectable calcium. If these two are not combined the sudden stimulation of the uterus will use up all available blood calcium levels for muscle contractions resulting in muscle paralysis. A single oxytocin injection generally results in the passage of one to two eggs. Injections may be repeated one hour after the previous egg was laid—allowing time for the calcium injection to be absorbed—for up to three doses per day. The female should then be allowed to rest for 24−48 hours. This process should be repeated until all of the eggs are laid. Completion of the egg laying process may be confirmed by palpation or by x-ray. page 128

Generally I medicate to stimulate the laying process in instances where a female lizard is starting to lose weight. However, medication does not necessarily result in a better prognosis, as it is associated with a number of risks. Very rarely does medication result in all eggs being laid at once, therefore multiple doses are generally needed. However, there is a limit to the number of doses that may be administered over a single day—usually two to three injections over a 12 hour period are all that will be readily tolerated. Excessive doses run the risk of over-stimulation and fatigue of the uterine muscles and will result in uterine spasm and muscular exhaustion. When medicating very small lizards, it can be difficult locating an adequate site to inject what is often a large volume of medication. Intraperitoneal injection can overcome this problem. Due to these limitations, it may take several days or weeks for a female to expel her full clutch of eggs. The stress of induction may itself result in her death, as may complications including acute calcium deficiency brought on by excessive muscle contraction, uterine infection and uterine prolapse caused by excessive uterine contractions and straining. Wait and Medicate This option offers the best of both worlds. If no egg is presented within two weeks of initial digging attempts, and the female is still of normal weight and alert, then oxytocin and calcium therapy should be provided to induce egg laying. In some individuals, initial stimulation may induce a female to lay the entire clutch. If this is not the case, implement medication as above. If medication fails to resolve the problem, surgery may be required to save the female. Although generally successful, a caesarean often predisposes the female to further dystocias. Eggs retrieved by surgery also vary in their viability—dragon and skink eggs removed by caesarean generally hatch if fertile and if uterine infection is not present, whereas monitor and gecko eggs rarely ever remain viable if retrieved through surgery.

UTERINE INFECTION This type of infection is uncommon and difficult to diagnose accurately. It should be suspected in repeated clutches of poor-quality eggs—particularly those that have become slimy during incubation. Eggs that have developed mould are more likely to simply be infertile. A cause may be identified through cloacal swabs or swabs of freshly laid eggs. Treatment may then be initiated. However, even if the infection is cleared, it is not uncommon for it to result in uterine scarring that will later render an individual unable to breed. Uterine infections should also be considered in instances of sudden death following egg laying—often within 5–10 days of the final egg being passed. The exit of eggs may allow environmental bacteria to enter the female’s body through the cloaca. There is some evidence to suggest that females likely to suffer dystocias—such as individuals showing signs of delayed egg laying—may benefit from prophylactic antibiotic treatment. This treatment is best based on cloacal culture and sensitivity.

HEMIPENAL INJURIES AND INFECTION Male lizards also suffer their share of reproductive problems. Hemipenal structures may occasionally become inflamed or infected. Hemipenes may occasionally be injured during mating—particularly those of boisterous species. Injuries may also occur if hemipenes extruded post-mating or post-defecation are bitten by other enclosure occupants—a fleshy pink tube looks like a food item to some hungry lizards. Any hemipenal injury may lead to swelling, which will prevent the hemipene from being retracted—leaving it exposed to abrasion, drying and infection. page 129

A ELLIOTT

The first priority is to protect the hemipenal structure from further damage by removing the lizard from its enclosure and placing it on a non-abrasive, clean surface such as a moistened paper towel. The hemipene may be kept moist with a combination of antibiotic ointment and petroleum jelly. Hemipenal swelling and pain can be reduced with oral anti-inflammatories. Antibiotics may be required to save the hemipene and should be chosen based on Geckos are able to clean their hemipenes and, therefore, bacterial culture and sensitivity. are less prone to hemipenal infections Hemipenes may also be damaged by substrate material. An infection may occur when a moist extruded hemipene becomes coated with substrate material and this material is drawn back into the hemipenal tube when the hemipene is retracted. A hemipene coated with faecal contaminated sand, bark pieces or grass will not remain healthy. Infections of this type are harder to ascertain, as the hemipene is hidden from view. The first indication of a problem may be cloacal discharge or an abscessed hemipenal pocket. It is less of a problem in geckos, which are able to clean their hemipenes by licking. Bacterial culture and sensitivity, antibiotics and anti-inflammatories are required to treat this condition. As hemipenes are a delicate structure coated with a sensitive mucous membrane, minor damage may render them non-functional. Their ability to be retracted may also be impeded. If a hemipene is rendered non-functional and cannot retract, it should be amputated by a veterinarian. Those that can retract but are abscessed should also be amputated. The lizard’s reproductive function should not be affected as all males have a second hemipene.

CONGENITAL DEFECTS Hatchlings will occasionally emerge from the egg with a physical deformity. The various types of these abnormalities are listed below. Deformities in live bearing lizards are less common than those in egg laying lizards—perhaps because deformities in utero result in pre-term problems that rarely persist long enough for the neonate to continue developing. Abnormalities occur for a wide range of reasons and determining the exact cause can be difficult. One hatchling or multiple specimens in a clutch may be affected. They may occur if, at any time during incubation, development of the embryo is interrupted or interfered with by environmental, nutritional, chemical or traumatic stimuli. This may be a single brief event—such as a sudden temperature spike, dropping of an egg or brief contact with a disinfectant spill—or a more prolonged event—such as a week of extremely hot weather or contaminated incubation medium. Sometimes the deformity may be the result of a genetic defect—either a one-off gene mutation or the result of the parent’s own genetic incompatibility. A single deformity within a clutch may be caused by local temperature issues such as eggs placed adjacent to heat elements, local humidity issues such as eggs leaning against container edges coming in contact with condensation, isolated genetic abnormalities and simple egg traumas such as the dropping of a single egg. Multiple abnormalities within a single clutch may be caused by genetic abnormalities associated with inbreeding, poor parental nutrition resulting in poor nutrient stores within the egg, excessively high incubation temperatures, excessively low incubation temperatures, page 130

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Bicephalism in a Nephrurus amyae

A shortened tail in a Pygopus schraderi hatchling following a temperature spike during mid incubation D BROWN

excessively high humidity, excessively low humidity, or contamination of incubation medium or eggs via hands contaminated with chemicals. The exact cause of some abnormalities may never be determined and it is unreliable to compare the cause of reptile abnormalities with those of mammal abnormalities—the causes of abnormalities within eggs may not parallel with the causes of abnormalities in utero. The most common include— Bicephalism This results in a hatchling being born with two heads and is believed to be a result of a single isolated genetic or fertilisation event within the egg. Anasarcia This results in fluid engorged and swollen hatchlings. It becomes apparent when eggs begin to sweat at the end of the incubation period but do not hatch. It is believed to be the result of excessive humidity, shell membrane abnormalities or neonatal calcium deficiency due to poor parental nutrition. Shistosomus reflexa This refers to ‘inside-out’ hatchlings. The abdominal contents of hatchlings affected by this deformity form externally to the body cavity or rupture through the body cavity during development. Although these hatchlings rarely hatch on their own, they may be alive when sweating commences or when siblings hatch. Possible causes include isolated genetic abnormalities, isolated high temperature spikes or chemical insults. Spinal and Limb Defects These range in severity from major spinal curvatures or twists to missing toes or bent tail tips. Most commonly they are a result of temperature issues, egg trauma or neonatal nutritional deficiencies. The severity of the defect is related to the precise developmental stage at which the insult occurred—if it occurred as the spinal column was developing, the spine may be developmentally abnormal and the limbs normal. Micropthalmia/Anopthalmia This refers to hatchlings born with small or absent eyes. As with spinal and limb abnormalities, it is thought to be the result of a precise environmental insult that occurred when the eye features were developing. Unlike many other deformities, individuals survive without too many other issues—unless the defect affects both eyes. Close-up of a tail defect in Pygopus schraderi

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An anasarcic Pseudothecadactylus lindneri— note the swollen neck skin

An anasarcic Pseudothecadactylus lindneri that has managed to emerge from its egg. Note the slight swelling in the forelimbs and the non reabsorbed yolk sac

Hermaphroditism This refers to individuals born with both male and female reproductive organs. It is usually the result of a developmental abnormality and does not affect the individual until breeding is attempted.

NASAL AND ORAL DISORDERS NASAL ABRASIONS—NOSE RUBS This type of abrasion rarely affects geckos but may occur in pygopods. It is caused by repeated trauma to the skin on the tip of the snout. It is generally the result of an individual repeatedly pacing up and down against a wire mesh surface to escape from a dominant individual, to attack a subordinate, to flee the keeper or to access more appropriate companionship or areas on the other side of the mesh. Repeated trauma may also be the result of a repeated concussive injury from leaping off a raised area onto a hard surface. The tissue on the tip of the snout is quite thin and overlies a bony area—healing in this area is often slow. Repeated trauma to a previously damaged area will cause thickened scar tissue to develop, which will further delay healing and result in an open ulcerated area often complicated by exposed bone. Treatment should commence with the correction of the husbandry issue that initially caused the problem—this is most important. In the short-term, move the individual to another enclosure or cover the wire with an opaque and/or soft material such as shadecloth, fibreglass fly mesh, poster cardboard or CorfluteTM. It may not be necessary to cover the entire surface—just the side where the rubbing is occurring. If the nose rubbing is occurring at ground level, cover the side to a height of 1−2 SVL—it is very hard for a lizard to rub its nose horizontally when it is standing vertically to reach over a barrier. For those specimens suffering trauma related to falling onto a hard surface, the provision of deeper and softer substrate is recommended. The nasal abrasion may self-heal once the lizard is removed from its enclosure. However, antibiotic ointments such as silver sulphadiazine may be used to control secondary infection and reduce scarring. Systemic antibiotics prescribed based on the results of a culture and sensitivity may be required to treat more severe cases. It is essential to dress the wound—I prefer products such as the ulcer cream DuodermTM combined with a surface coat of wound sealant OpsiteTM. These provide a moist, protected environment for healing to take place. The wound should be dressed every one to two days to encourage the development of a healthy healing surface. Treatment should continue for four to six weeks or until the last scabs have healed. page 132

In very severe cases, the aim of treatment may be to primarily stop infection. The chronic scarring and deficits in the skin surface may result in permanent disfigurement. If exposed jaw bones are involved then the best aim is to encourage granulation tissue (healing tissue bed) to cover the bone to prevent deeper infection, which may compromise healing. In some cases, the provision of vitamin A supplements may improve healing rates.

JAW DISEASE/PERIODONTITIS/STOMATITIS This disorder is generally uncommon and can occur in all lizards. It is often caused by nose rubbing or direct tooth trauma associated with biting hard objects, such as biting gravel instead of a food item, or injuries from other lizards. Large aggressive gecko species such as Pseudothecadactylus or Cyrtodactylus spp. may develop problems from damaging their teeth when fighting over food items. Jaw wounds where there is no significant underlying problem can be flushed out using diluted BetadineTM and topical or systemic antibiotics initiated. Daily cleansing of the wound is essential— this cleansing should be delayed and treatment initiated without it if the initial cleaning causes significant bleeding. A delay of three to seven days is suitable to allow some healing to take place. Plaques of necrotic tissue should be flushed or picked clear of the wound, as they will significantly inhibit healing. Care must be taken not to destabilise the jaw with excessive debridement. If the jaw bone is infected it will be weakened and may fracture easily—repairing fractured jaws is slow and often unrewarding. Jaw disease may be secondary to metabolic bone disease, which predisposes jaw bones to uneven wear patterns and overall weakness. It can occur in highly productive females that have weakened bones from overutilisation of stored calcium.

ADMINISTRATION OF MEDICATIONS

Subcutaneous or Intramuscular Injections

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There are various methods for administering medication to reptiles—which method you pursue will depend upon the drug being used and the ailment being treated. Common methods include—

Injections are the most direct and often the most effective method for administering medication. Use of the correct injecting technique is important, as an incorrect technique may damage a specimen. Technique is not difficult to learn and your reptile veterinarian will be able to demonstrate it to you. This method of administering medication will save your veterinarian time and yourself money, as it allows the injections are useful for a range of medication veterinarian to provide you with a full Subcutaneous types. The loose skin over the shoulders is an accessible area course of medication that you can take home and administer yourself. Subcutaneous injections are administered under the skin and are best given in the loose skin found above the shoulders of most species—some skinks and pygopods are tight skinned and page 133

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Intramuscular injections are a more direct route for some medications. The muscles of the forelimbs may be used

The muscles of the hind limbs may also be used

difficult to inject subcutaneously. The tip of the needle is inserted into the free space between the skin and the muscle, where there is a space to receive the bolus of medication. Lizards generally do not like receiving injections—having a second person to handle the specimen may be helpful. Intramuscular injections are administered into the muscle and can be given in a number of sites—I recommend the top of the shoulder or the muscles of the forelimbs, although the tail base may also be used. The tip of the needle is inserted through the skin and into the muscle tissue at an approximate angle of 45 degrees. The medication is deposited within the muscle. Intramuscular injections are used to administer medications that may irritate the skin. They are also suitable for medications that are better absorbed into the muscle than into subcutaneous tissue.

Liquid Oral Medication Oral medication is recommended when injections cannot be given or if medication is required over an extended period of time. This method of administering medication is particularly suited to very small or tight-skinned species that cannot be injected or when repeated injections have become painful. Oral medication may be administered directly into the mouth of a specimen or deposited into the stomach through a stomach tube. Administering oral medication directly into the mouth of a lizard is easy if the individual voluntarily opens its mouth. If not, the mouth must be opened manually—I recommend using a modified 1ml syringe with its tip cut at an angle to provide a pointed lever for opening the mouth. Some species will lick the medication up when it is slowly injected at the front of the oral cavity. With other species, the syringe may need to be inserted further into the mouth to ensure the medication is deposited at the back of the mouth. Accurate dosage can be difficult with very small specimens and an overdose can occur when using an eye dropper or syringes. A simple, accurate micro-doser can be made out of a standard hypodermic needle and be used to deliver very tiny doses of medicine to very tiny patients. Each needle size or gauge has a different internal and external diameter. Therefore, each needle forms page 134

a different sized volume drop at its tip when fluid is expressed. To avoid needle stick injuries, grasp the needle at the base and snap the tip off to make a short, stubby needle for dosing. The following table shows the expected volume for liquid medications from different sized needles in the micro-doser state. Applicator Size

Volume Delivered

29 gauge

0.005 ml/drop

25 gauge

0.008 ml/drop

23 gauge

0.01 ml/drop

20 gauge

0.015 ml/drop

18 gauge

0.02 ml/drop

Tip of a 1ml syringe

0.035 ml/drop

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Individuals that spit oral medication out will require medication to be deposited beyond the oral cavity. When doing this, the syringe will usually enter the oesophagus—but it must not enter the windpipe (glottis)—this should be easy to spot in most species. To deposit medication beyond the oral cavity, gently prise the lizard’s mouth open with the tip of the syringe, which should then be repositioned along the angle of the jaw to keep the jaw open. I recommend the use of a short, stiff feeding tube—this is generally A modified syringe may be used to easier to position than a long, flexible one. Your administer small amounts of oral medication veterinarian should be able to supply a feeding tube, avian crop gavage needle, tom cat catheter or a piece A micro-doser of drip set tubing for this purpose. The tube should be made from a placed at a depth equivalent to the level of the shoulders— needle is used measure this beforehand and mark it with pen on the for administering tiny doses of tube for easy identification. Once at the correct depth, the medication medication should then be injected slowly to prevent it from spraying back up the oesophagus. This method is best performed with the assistance of another handler or with the specimen wrapped in a light towel. A gecko being treated with an oral calcium supplement using a syringe tip

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Oral Tablet Medication Some medications are best administered in tablet form, as the oral dose may be too large in volume or the medication may not be available in liquid form. A tablet is inserted into the back of a lizard’s mouth or into a food item such as a pinkie mouse. This food item may be fed as usual or inserted into the lizard’s mouth.

MAKING THE MOST OF YOUR REPTILE VETERINARIAN Reptile medicine is still in relative infancy when compared with dog and cat medicine. Despite this, many good reptile veterinarians are available in Australia. Getting good results from a reptile veterinarian often requires some forethought by the keeper. Developing a good rapport with your veterinarian will benefit yourself and your reptiles. There are several things you can do to improve the results obtained by your reptile veterinarian— Treat early Early presentation of an ill or injured lizard results in an earlier diagnosis and a greater chance of treatment success. Waiting until tomorrow rarely benefits the specimen. Observe Recognising early signs of disease requires keen observation of the lizard’s physical features, appetite and behaviours. Subtle changes in faecal colour and shape, basking site use, sociability and feeding can provide early clues of a problem. Physical changes such as closed eyes, swellings, oral and nasal discharges, weight loss and shedding abnormalities are all signs to take seriously. Be honest When discussing your case with your veterinarian, be honest about your husbandry methods. Many health problems are directly related to husbandry issues. Not revealing lapses in husbandry for fear of looking like a bad keeper will seriously reduce your veterinarian’s ability to assist. If these husbandry issues are not addressed, all the medication in the world will not help your lizard. Listen Too many times as a veterinarian I have seen lizards die because keepers have ignored what I have told them. Instructions should be followed—whether they are changes to husbandry or dosage instructions. Deviating from a veterinarian’s instructions to follow advice on an online forum is equally as unhelpful. Provide input A consultation is not a one-way engagement. Ask questions and provide your own observations. Not every veterinarian is familiar with every species—a consultation can be a learning experience for both parties. Learn Ask the veterinarian to demonstrate the techniques used to reach the diagnosis and the methods used for treatment. Learning how to provide medications by means of intramuscular or subcutaneous injections can greatly improve treatment outcomes. Learning diagnostic methods may allow you to provide better samples when required, as an understanding of the procedures will help to understand their limitations. Do not be cheap Choosing the cheapest option based on the value of an individual lizard may not be the best decision. Consider the individual as the whole collection and the single sick specimen as a means of treating the entire group. A few extra dollars spent on valuable diagnostics may save several specimens rather than one. Disclose your budget at the beginning of the consultation to allow the veterinarian to pursue the diagnostic treatment that you can afford. page 136

Seek reputation When seeking a veterinarian, a high price does not always signal the best person for the job. Likewise, an affordable veterinarian will not always result in the worst results. Assess each veterinarian on their own merits—consider their reputation and skills. Most online forums, dealers, breeders and clubs will have a list of recommended veterinarians. It is worth spending an extra $50 on fuel to travel to a well-respected vet. Avoid DIY treatment Do-it-yourself home treatments may work at times, however they invariably impede correct treatment. This may be because the disease is well advanced before veterinary treatment is sought or because inappropriate treatment has masked the true nature of the disease. Uninformed treatment advice can sometimes worsen a disease or create a whole new issue. Although many lizard breeders are very experienced with husbandry, it is not uncommon for their knowledge of reptile medicine to be blurred by personal opinion and ignorance. Treatment should be based on diagnosis—not suspicion or internet advice. Monitor heating A cold and sick lizard is a dead lizard in most cases. Environmental temperature controls every part of a lizard’s day, including its body temperature and immune system. In most species, the immune system switches off once it falls 2oC−3oC below its optimum body temperature. Regardless of the time of the year, an unwell lizard must be brought back up to optimum temperature for the treatment period. Be patient Treatment takes time. Even the most basic of skin infections take two to three weeks to fully recover from. Anything more significant may take between six and eight weeks or longer to resolve. Shortcuts invariably result in relapses, which may be harder to treat the second time around when drug penetration is complicated by excessive scar tissue. Provide samples Good samples result in good diagnostics. Wherever possible, regardless of the presenting condition, bring along any fresh diagnostic specimens such as fresh faecal material. Good, clean and fresh samples are worth their weight in gold. Keep dead specimens The next best diagnostic sample is a well-prepared post mortem specimen. However, the value it may provide depends on the way it has been stored in the period immediately following its death. A deceased lizard should be stored in the refrigerator within six to eight hours of death or sooner if possible—this slows down the deterioration of tissues and viscera. Never freeze the specimen if possible—if frozen, the best information that can be obtained is that of gross lesions or significant parasite burdens. Freezing and thawing significantly disrupts cells, making them useless for further diagnostics. It is best to store a dead lizard in moist newspaper, then place this within a clean plastic bag or two and store it in the crisper section of the refrigerator. The refrigerated specimen should be given to the veterinarian within 24 hours, however useful information may still be obtained two to four days after its death. Some pathogens—particularly flagellate protozoans—will not be identified in a refrigerated specimen, as they die when chilled. Prevent Prevention is better than cure. Veterinarians play an important role in preventative and proactive medicine by providing advice on worming strategies, pre-cooling health checks, hygiene and assisting with sexing methods. page 137

SPECIES page 138

G SCHMIDA

Heteronotia binoei

BYNOE’S GECKOS AND DESERT CAVE GECKOS The Bynoe’s Gecko and Desert Cave Gecko group comprises three species as follows— Bynoe’s Gecko or Bynoe’s Prickly Gecko Heteronotia binoei North West Prickly Gecko Heteronotia planiceps Desert Cave Gecko Heteronotia spelea

PRONUNCIATION Following are the accepted pronunciations of the Bynoe’s Gecko and Desert Cave Gecko species. Heteronotia binoei Het-err-owe-no-she-ah bye-no-ee Heteronotia planiceps Het-err-owe-no-she-ah plan-ee-seps Heteronotia spelea Het-err-owe-no-she-ah spell-ee-ah

DESCRIPTION ADULTS Members of the Bynoe’s Gecko and Desert Cave Gecko group are of small size with slender bodies, long tails and longitudinal rows of granular scales. Each species is of similar size measuring an average of 50–56mm SVL. A typical specimen measuring 50mm SVL will weigh an average of 3−3.5 grams. The Bynoe’s Gecko H. binoei varies in colouration from greyish brown to reddish brown and blackish, with scattered darker and paler spots  and paler narrow banding on the body. This page 139

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Heteronotia binoei

Heteronotia planiceps

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Heteronotia spelea D BROWN

variation is partially due to the presence of several undescribed species included under this name. The North West Prickly Gecko H. planiceps is more uniform in colouration, ranging from yellowbrown to red-brown with 3–5 sharp-edged dark brown bands on the body, with pale interspaces that are narrower than the body stripe. A dark eyestripe joins the first brown band across the back of the head. Original tails are also banded, however regenerated Hatchling Heteronotia binoei tails are not. The Desert Cave Gecko H. spelea is similar in colouration to the North West Prickly Gecko H. planiceps, except that the body bands are restricted to 3–4, which are of similar width to the interspaces between them.

JUVENILES Hatchlings are a brighter version of the adult but generally display darker and more distinctive banding and patterning. They are 15−20% of average adult size at hatching. page 141

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Lateral view of the paracloacal spurs of a female Heteronotia binoei

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Lateral view of the paracloacal spurs of a male Heteronotia binoei D BROWN

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Ventral view of a female Heteronotia binoei—note the small paracloacal spurs

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Ventral view of a breeding male Heteronotia binoei—note the tubular hemipenal bulges

Ventral view of a non-breeding male Heteronotia binoei—note the absence of obvious hemipenal bulges, the large paracloacal scales and the preanal pores with ‘pegs’ on the right side

SEXING

These geckos are moderately easy to visually sex as adults. Adult males display hemipenal bulges, which appear more tubular in structure and less obvious in this group, rather than bulbous as in other gecko species. They also appear to Ventral view of endolymphatic regress in size and become Lateral view of an endolymphatic calcium sac in a female Heteronotia calcium sacs in a female very difficult to see in the non Heteronotia binoei binoei breeding period. Males possess a row of 4−6 preanal pores that vary in their visibility—sometimes they are obvious due to pigmentation, at other times they may need to be magnified. They are absent or barely visible in females. They may exude a secretory material that extends as ’pegs’ from the pores. page 142

Females possess obvious endolymphatic calcium sacs during the breeding season. They are positioned under the skin, low on the dorsal neck, between the shoulder and ear and act as a store of calcium. Hemipenal transillumination can be used on hatchlings, sub adults and adults. Paracloacal spurs are present in both sexes and comprise 2−3 blunted spurs arranged in a fan shape. In males, the individual scales are roughly 2−3 times the size of the adjacent scales. The ventral base often appears paler than adjacent scales. In females they are no more than 1.2−1.5 times the size of the adjacent scales. In non breeding periods, these may be an important indicator of gender. Juveniles can be reliably sexed once they have reached 60−70% of adult SVL—attainable at 5−10 months of age, depending on feeding frequency.

SUBSPECIES There are no recognised subspecies in this group. However, the Bynoe’s Gecko H. binoei is considered to comprise numerous undescribed species. At least five genetically different sexual forms and numerous asexual forms—referred to as parthenogenetic Heteronotia species—are described at DNA level. Despite this, no subspecies of the Bynoe’s Gecko H. binoei have been officially recognised due to the lack of reliable distinguishing features between the undescribed forms—without these features herpetologists are unable to establish a reliable key. The parthenogenetic populations possess the ability to produce offspring from unfertilised ovum or eggs. It is possible in some significant overlapping areas to find multiple sexual populations and parthenogenetic populations coexisting in the same geographical area. Further study will help to specifically characterise each population so that more accurate ‘species’ names can be applied to them. There are no known subspecies of the North West Prickly Gecko H. planiceps or the Desert Cave Gecko H. spelea.

IN THE WILD D FISCHER

DISTRIBUTION AND HABITAT The Bynoe’s Gecko H. binoei is one of the most widespread and abundant gecko species in Australia. It is found throughout most of arid Australia excluding in the south-eastern and south-western corners of the continent. Its habitat includes rocks, logs, dead vegetation, loose bark at the base of trees, soil cracks and surface debris such as roofing iron and discarded timber. Habitat of Heteronotia spelea, Karijini, Western Australia

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Habitat of Heteronotia binoei—discarded tin piles, Mount Korong, Victoria

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The North West Prickly Gecko H. planiceps is found in a narrow band across northern Australia from the Kimberley region of Western Australia to Groote Eylandt off the coast of the Northern Territory. Its primary habitat is rock escarpments, where it shelters in rock crevices, in caves and beneath rocks. The Desert Cave Gecko H. spelea is restricted to the Pilbara region of Western Australia. Its habitat is similar to that of H. planiceps.

Habitat of Heteronotia binoei, Coonamble, New South Wales

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IN CAPTIVITY STATUS

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Heteronotia binoei

The Bynoe’s Gecko H. binoei is common in captivity and is an ideal beginner’s species, being quite affordable. It is popular with beginners and experienced keepers alike. This popularity is likely to increase as each unique form is reclassified as a new species and more parthenogenetic forms are established. The North West Heteronotia binoei Prickly Gecko H. planiceps and the Desert Cave Gecko H. spelea are rare in captivity—most Desert Cave Geckos H. spelea currently in captivity are actually an undescribed similar form from Alice Springs in the Northern Territory.

HOUSING The Bynoe’s and Cave Gecko group are among the most opportunist gecko species and will inhabit almost any available habitat within their range—making them very easy to maintain in captivity. They are entirely terrestrial and good-natured, generally cannot climb and have very few specialist requirements. page 145

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Heteronotia planiceps

INDOOR ENCLOSURES Suitable enclosures include plastic terrariums, fish tanks, commercial terrariums and plastic tubs. These should measure at least 4−6 SVL long x 4−6 SVL wide x 2−3 SVL high. These geckos make the most of the available space, therefore enclosures do not need to be very large or high. In excessively large enclosures, they will limit their activity to areas adjacent to their hides. Large enclosures will also make it more difficult for them to catch their meals before dusted insects have rid themselves of calcium or vitamin powder. Lids are not essential, except in fish tanks where occupants may be able to scale silicon sealant in the corners of the tanks. Suitable substrate is desert or beach sand. Substrate depth is not important, as this species is not a burrower. Occasionally it may bury or partially cover its eggs in shallow scrapes in loose sand under hides. Provide upturned plant saucers, pieces of bark, flat stones or timber pieces for use as hides. As these geckos do not dig, furnishings can be arranged loosely with little fear they may collapse. Heating is simple to provide for this species in captivity. Heat cords or a heat mat placed under part of the enclosure can be used to provide subfloor heating. Alternatively, a small incandescent or halogen heat lamp may be directed onto a hide site, such as a flat piece of rock—it will supply radiant heat to the sand below the hide. The substrate should be heated to 25oC−28oC for 10−14 hours per day. An overall enclosure temperature gradient of 20oC−28oC is ideal. During winter, temperatures for adults can fall to 15oC−20oC. Active cooling over winter is only considered necessary for breeding geckos. Juveniles do not need to be cooled during winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. The provision of UV-B light is not essential for these species, although it may benefit breeding page 146

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females—they lay hard-shelled eggs and have greater requirements for calcium metabolism than other gecko species. A UV-B lamp of 5% UV-B is recommended. A bowl containing fresh water should be available at all times, however enclosures may also be sprayed.

Summary A basic enclosure for Bynoe’s Geckos and Desert Cave Geckos should include the following— • A substrate of sand. • Small bark slabs, flat rocks, pieces of plywood or terracotta saucers. • Underfloor heating or a small heat lamp providing a substrate temperature of 25oC−28oC. Components of a suitable enclosure • A water bowl.

OUTDOOR ENCLOSURES

S MACDONALD

The extremely adaptable nature of these geckos means they are quite capable of living outdoors in most climatic zones and they have been maintained in this way by researchers at universities for many years. As a private keeper, although this could be achieved easily using large plastic tubs or smooth sided pits, the occupants spend the entire day under cover and are not visible unless you dismantle the enclosure.

Heteronotia sp.

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COMPATIBILITY These species are generally placid towards each other. They can be housed in pairs, trios or larger groups. Unlike many gecko species, multiple males can be housed together in larger enclosures—such as two males with 3−4 females in an enclosure with a floor measuring 60cm x 30cm with ample hides at both ends. With parthenogenetic species, several females may be housed together without significant aggression problems.

FEEDING In the wild, these species feed on small spiders, small cockroaches, crickets, moths and any other arthropods available. They feed by running after food items or waiting in ambush until a food item comes closer. In captivity, they will accept any small terrestrial insect including crickets, termites, slaters and very small cockroaches. Food items should measure approximately 50% of an individual’s head size. They should be lightly dusted with a suitable calcium/vitamin D3 supplement in at least two out of three feeds. Breeding females can be given dusted food at every meal, due to their increased need for calcium at this stage. In addition, a bowl of calcium carbonate powder can be supplied, allowing females to lick the powder if they require additional calcium. Adults should be fed every 4−7 days in summer and every 7−10 days in winter, although they may not accept food for short periods during this time. Sub adults should be fed every 2−4 days throughout the year to allow for continued growth.

BREEDING

S EIPPER

In the wild, breeding occurs from September to March. In captivity, breeding is the same, although some females may breed at any time of the year if conditions are suitable. Individuals are capable of reproduction when they reach 9−12 months of age, however it may be more suitable to delay breeding until they are fully matured. Pair separation is not essential for breeding success and pairs may be maintained together throughout the year with few problems. If cooling is practiced, it can be achieved by gradually reducing temperatures during winter to 15oC−20oC during the day and to 10oC−15oC at night. Cooling is not generally required with these species, as local ambient temperature changes are usually sufficient. Courtship and mating is usually quite secretive and presumed to occur within hide sites. The first eggs of the season should be expected approximately six weeks after ambient daytime temperatures rise above 20oC. A gravid female can be identified by a marked increase in girth. The eggs will be visible as distinct pale shapes through her abdominal wall. A typical clutch is two eggs. The eggs are almost round in shape and hard-shelled. They are sticky when first laid, which can cause the substrate to stick to them. A female Heteronotia binoei with an egg clearly visible through the abdominal wall

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They dry rapidly and are hard and brittle within 30 minutes of laying. Up to three clutches are laid per year, with five possible in some cases. Different egg laying strategies are used within parthenogenetic populations—some females will produce only a small number of eggs, but with good fertility, whereas others will produce numerous clutches with poorer fertility. The interval between clutches is usually 3−4 weeks. Females must be fed an appropriate diet after laying their eggs to assist them in regaining condition rapidly in preparation for the next clutch. As the eggs produced are hard-shelled, females should be supplied with calcium supplementation during each feed. Alternatively, a shallow bowl of dry calcium powder can be supplied. In the wild, females usually nest in spaces under rocks, logs and matted vegetation. In captivity, some will simply lay on top of the sand under bark pieces, or they may partially bury their eggs. Others may nest in a nestbox containing a mixture of dry sand and coir peat. Eggs are generally not buried very deep in the substrate. As with other species that lay hard-shelled eggs, egg laying sites are best kept dry to avoid the egg spoilage associated with moist sites. Some breeders supply a moist nest box, but I have personally experienced less success and more spoilage using this technique. In some areas the Bynoe’s Gecko H. binoei has been recorded nesting communally, with up to 150 eggs layered up to four deep in a single site. It is unclear whether this is a preferred behaviour or if it reflects a lack of suitable nest sites in that area.

INCUBATION AND HATCHLING DEVELOPMENT Once laid, the eggs may be collected for artificial incubation or they may be allowed to hatch naturally within the enclosure. Incubation should be in a mixture of water and vermiculite at a ratio of 1:3 by weight or 1:30 by volume. Incubation medium should be relatively dry. Incubation is relatively simple and without problems in these species, although incubation periods are generally unpredictable in enclosures—this doesn’t affect hatchability if the substrate conditions are stable. Eggs should be incubated at temperatures of 26oC−30oC. Egg expansion is much less than that experienced with soft-shelled eggs. The fertility and viability of the eggs is indicated by their colour. Fertile eggs change from pink to lavender to light grey as development progresses, whereas infertile eggs or eggs with early mortality are creamy white. The presence of blood vessels can also indicate fertility if the eggs are candled in the first week or two. Blood vessels are less visible when eggs are candled at a later stage. Egg sweating is not a typical pre-hatch feature in this species.

BREEDING RECORDS FOR BYNOE’S GECKO AND DESERT CAVE GECKO SPECIES Species

Clutch Size

Interclutch Interval (Days)

Egg size (mm) (Mean or Range) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

H. binoei

2

14−88

9.5 x 6.5

68 (28oC−29oC) 65-80 (variable room temperature)

35−40

H. spelea

2

–

–

–

–

H. planiceps

2

–

–

–

– page 149

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small holding container furnished with a small hide—such as a toilet roll or similar— and a water bowl. I have maintained Bynoe’s Gecko H. binoei with no substrate or on a substrate of shallow desert sand with no apparent issues. Enclosures should be heated as for adults, with underfloor heating being the easiest to control. Food should be offered 24 hours after hatching. Initially, items should be limited to hatchling crickets or termites. Once hatchlings begin to grow, items measuring approximately 50% of the hatchling’s head size can be offered. Adult size should be achieved after 12 months.

HYBRIDISATION AND COLOUR VARIANTS

P HART

Hybridisation and colour variants have not been recorded in this species. The Bynoe’s Gecko H. binoei is morphologically cryptic, which makes it very difficult to be certain whether the same genetic groups are being mated together. All that herpetologists can do to attempt to maintain genetic integrity is to mate lizards from similar geographic locations or only mate lizards similar in appearance. Parthenogenetic offspring are, by definition, ‘exact’ copies of their mothers, which has resulted in several attractive clone types being established in captivity. There is still subtle variation within these populations, ensuring further selection of attractive features can be accomplished.

A ‘Sandstorm’ parthenogenetic clone Heteronotia

LONGEVITY Bynoe’s Geckos and Desert Cave Geckos live reasonably long lives for such small species. The average life span is 6–7 years with a productive period of 4–5. Occasionally, specimens of 8–9 years of age have been recorded.

ACKNOWLEDGEMENTS I would like to thank Pete Nunn, John McGrath and Michael Kearney, among others, for their assistance with this chapter. page 150

A ELLIOTT

Gehyra variegata

DTELLAS AND HOUSE GECKOS The Dtellas and house gecko group comprises at least 21 species of gecko—17 Gehyra species, Hemidactylus frenatus and three Christinus species including— Northern Dtella Gehyra australis Chain-backed Dtella Gehyra catenata Dubious Dtella Gehyra dubia Robust Dtella Gehyra robusta Variegated Dtella Gehyra variegata Asian House Gecko Hemidactylus frenatus Marbled Gecko Christinus marmoratus

PRONUNCIATION Following are the accepted pronunciations of the most common members of the Dtella and house gecko species. Gehyra australis Gee-high-rah os-trah-liss Gehyra catenata Gee-high-rah cat-en-art-ah Gehyra dubia Gee-high-rah dew-bee-ah Gehyra robusta Gee-high-rah row-bus-tah Gehyra variegata Gee-high-rah var-ee-gah-tah Hemidactylus frenatus Hem-ee-dack-tile-us fren-ah-tus Christinus marmoratus Chris-tee-nus mar-more-ah-tus page 151

S MACDONALD

Gehyra australis

DESCRIPTION ADULTS

G SCHMIDA

The Gehyra genus within Australia comprises at least 17 species of arboreal geckos. They are small in size with stocky bodies covered in smooth, fine, granular scales and have rounded, thick tails potentially used as nutritive stores in lean periods.

Gehyra catenata

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G SCHMIDA

Gehyra dubia

D BROWN

They range in size—the smallest species Gehyra minuta measures 45mm SVL and the largest species Gehyra baliola measures 101mm SVL. The majority of species measure 55–75mm SVL.   Colouration varies, although Gehyra species are generally known as the LBJs—‘little brown jobs’—of the gecko world. All Australian species are generally shades of grey, pink and brown and are capable of considerable variation depending on the substrate on which they reside and the time of the day. They display cryptic, often complex patterning comprising various combinations of spots and stripes in brown, white and black—these patterns are used to distinguish many species.

Gehyra robusta

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G SCHMIDA

Hemidactylus frenatus

G SCHMIDA

Hemidactylus comprises more than 65 species of which only the Asian House Gecko H. frenatus is found in Australia. They have a pointier face than Gehyra species as well as backward-pointing spines on the sides of original tails. They vocalise constantly and generally measure 60mm SVL. The Christinus genus comprises at least three species of gecko that are less stocky than Gehyra species. They generally measure 60–80mm SVL. A typical specimen measuring an average length of 60mm SVL will weigh an average of 6–7 grams.

Christinus marmoratus

page 154

JUVENILES Hatchlings are similar in colouration and patterning to the adult. Hatchling Gehyra, Christinus and H. frenatus are often quite small in comparison to other geckos of equivalent adult body size. This may be because they lay substantially smaller, hard-shelled eggs—sometimes 50% smaller— than similar-sized geckos of other species that lay larger oval, leathery-shelled eggs. They are generally 15−25% of adult SVL.

SEXING  

D BROWN

D BROWN

Ventral view of a female Gehyra dubia

D BROWN

Ventral view of a male Gehyra dubia D BROWN

D BROWN

Dtellas and house geckos are easy to visually sex as adults. Adult males of all species and groups display significant hemipenal bulges—females display some enlargement in this area but it is less developed and without a central depression. Dtellas Gehyra species possess 10−20 preanal pores that are generally more visible in males. Adult male Dtellas Gehyra and Asian House Geckos H. frenatus possess moderate paracloacal spur clusters comprising 2−4 enlarged scales, which may be asymmetrical, and are generally up to twice the size of adjacent scales. They are larger in males—enlarged scales in female spur clusters are usually no more than 50% larger than adjacent scales. Christinus males possess a single pointed paracloacal spur on each side that is absent in females.

Ventral view of male Gehyra robusta showing preanal pores and paracloacal spurs

Female Gehyra robusta with large endolymphatic calcium sacs

Male Gehyra robusta with smaller endolymphatic calcium sacs

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A male’s preanal pores and hemipenes may reduce in size if he is housed alone, housed with a dominant male or it is not breeding season. The hemipenal spurs in inactive males always remain larger than that of females. Males and females often have well-developed endolymphatic calcium sacs located on the sides of the neck. These sacs store the calcium needed for egg production, therefore they are invariably smaller in males. They may be enlarged in growing juveniles—presumably to store calcium for bone growth. Hemipenal transillumination can be used on hatchlings measuring more than 40% of adult SVL, sub adults and older adults. Juveniles can be sexed once they reach 50−60% of adult SVL, which may occur at 6−12 months of age with adequate nutrition.

SUBSPECIES Only one species within the Australian species of Dtellas Gehyra has recognised subspecies. Gehyra koira is separated into G. k. koira from the Ord and Victoria River region of the north-western Northern Territory and north-eastern Western Australia, and into G. k. ipsa from the Bungle Bungle Ranges in Western Australia. These lizards differ in the number of scale rows between the eyes, overall size and the number of preanal pores. Due to the fact that differences between species are seldom striking, it is likely that some wide-ranging species will ultimately be split into separate species or subspecies when eventually investigated. Similarly, new species are likely to be described in remote areas where ‘small, brown geckos’ are often overlooked by naturalists in favour of more ‘exciting’ species. The Asian House Gecko H. frenatus has no subspecies. Christinus is an endemic Australian genus comprising three species, although this may also include several additional undescribed species or subspecies. It comprises Christinus alexandri— formerly a subspecies of the Marbled Gecko Christinus marmoratus—from the Nullarbor Plain, Christinus guentheri from Lord Howe Island and Norfolk Island and the Marbled Gecko C. marmoratus from southern Australia in Shark Bay, Western Australia, to the Warrumbungles, New South Wales. Several chromosomally distinct groups occur within the wide range of the Marbled Gecko C. marmoratus, however, they are yet to be given species or subspecies status as they are very similar in appearance.

IN THE WILD DISTRIBUTION AND HABITAT Dtellas Gehyra and the Asian House Gecko H. frenatus are distributed throughout the world. Within Australia, Dtellas Gehyra are found throughout much of the northern part of the country. Only the Dubious Dtella Gehyra dubia and the Variegated Dtella Gehyra variegata are found in the southern half of the continent. Of the 17 Dtellas Gehyra species found in Australia, 14 are endemic to the Australian mainland. No species occur in Tasmania. Gehyra mutilata and Gehyra oceanica are present only on offshore islands or in Australian island territories—they are considered an extralimital species. Dtellas Gehyra inhabit open forest, shrubland, riverine woodlands and rocky outcrops. Some species have developed an affinity with human habitation and may be found in and around buildings. By day, they shelter in any available crack or crevice in rocks, under bark or in artificial structures such as timber piles, brick stacks and within cavity walls. In some areas, several species page 156

G SCHMIDA

Habitat of northern Gehyra species, Chillagoe, Queensland

Habitat of western Gehyra species, Karijini, Western Australia

S EIPPER

D FISCHER

S MACDONALD

may overlap and use different niches or share different aspects of similar habitat. The Asian House Gecko H. frenatus is an introduced species in Australia, Africa and the Mediterranean. Its natural range is throughout most of Asia. In Australia, its range follows that of major highways, suggesting it is dependent on human settlements to spread. It is still not known if this species can colonise in the absence of humans—it appears to disappear from human settlements after they have been Habitat of southern Gehyra species, the Warrumbungles, abandoned. New South Wales Christinus are found in the most southern regions of Australia, filling the range where Dtellas Gehyra species are absent. They are able to exploit these cool temperate and windswept island areas using their unique reproductive strategies. They are also found around human dwellings.

Habitat of Christinus marmoratus and Gehyra variegata, Mount Korong, Victoria

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S EIPPER

Hemidactylus frenatus

IN CAPTIVITY STATUS Dtellas and house geckos are held in moderately low numbers in captivity due to their lack of bright colours and small size. The Marbled Gecko C. marmoratus is the most popular species and is an ideal beginner’s pet—it is easy to acquire and affordable. Many of the northern Gehyra species would be of more interest to herpetologists if they were introduced into the captive population—they are a significant size and display attractive patterning.

HOUSING All species in this group are arboreal, extremely opportunistic and easy to maintain in captivity. Dtellas Gehyra species are particularly tame and tolerant once they become accustomed to their keeper, however, they do not tolerate handling well and may shed their tails with little provocation—this is less of a problem with Christinus species.

INDOOR ENCLOSURES All species in this group are extremely adaptable in captivity and can be housed in most types of enclosures. These should measure a minimum of 3 SVL long x 3 SVL wide x 3−5 SVL high for pairs. Enclosures do not need to be particularly large, as all species use all available surfaces inside. Height is not essential if horizontal hides are provided. Tight fitting lids are essential—these geckos are particularly fast and can scale glass with ease. The Robust Dtella Gehyra robusta in particular is capable of a unique vertical hopping movement, similar to a frog, but much faster and more accurate. page 158

D BROWN

Floor substrate is not important, however a thin layer of sand will reduce the amount of faeces that stick to the floor of the enclosure. Hide sites can be provided in virtually any manner—vertical or horizontal. Hides may be constructed using anything from egg cartons to stacked timber or bark rolls. These geckos prefer a relatively tight fit—gaps of a similar size to an individual’s body width are ideal. Basking behaviour and heating requirements vary between species. Dtellas Gehyra and Asian House Geckos H. frenatus found in the northern half of Australia require an enclosure temperature of 22oC−30oC for 10−14 hours per day in summer and 15oC−20oC in winter. Christinus are less heat tolerant due to their southern origins—they should be maintained below 26oC at all times—or at least have hide sites that can achieve these lower temperatures. Heat cord or heat pads can be used for heating. A heating lamp or bulb may also be suitable—many Dtellas Gehyra and Asian Components of a suitable enclosure House H. frenatus geckos tolerate lights and will forage around them. Light bulbs should be located outside of the enclosure or placed in a light cage to discourage occupants from sleeping in the gap between the bulb and the light socket. Active cooling during winter is only considered necessary for breeding geckos. Juveniles do not need to be cooled over winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. These species do not require UV-B light but, if provided, it should be of 5% UV-B. A bowl of fresh water should be made available at all times.

Summary A basic enclosure for Dtellas and house geckos should include the following— • A thin substrate of sand or light leaf litter. • Overlapping horizontal or vertical slabs providing numerous hide spaces 0.5−1cm wide. • A heat pad, heat cord or small heat lamp providing a temperature of 22oC−30oC. • A dry sand hide site to serve as a nest box. • A water bowl.

OUTDOOR ENCLOSURES Many of these species can be maintained outdoors but, due to their cryptic nature and nocturnal habits, are not ideal specimens for this type of housing. They may be active display animals if the outdoor enclosure is mounted near an outdoor lamp or window where natural nocturnal insects can be used as a food source to stimulate interest. page 159

COMPATIBILITY Dtellas Gehyra and Asian House Gecko H. frenatus species display a high level of aggression and should be housed as pairs or groups of one male and multiple females. Multiple males maintained in one enclosure will fight brutally. Christinus species are somewhat more peaceful and can be maintained in large groups of multiple males—I keep mine in groups of one male with 2−3 females.

FEEDING In the wild, this group feeds on any form of insect available. Some Dtellas Gehyra species have been observed feeding on Acacia sap and Grevillea nectar.   In captivity, all species will accept any insect item offered including crickets, flies and roaches in particular. They also enjoy moths and will take termites or maggots from a bowl as juveniles. Insect item size should measure approximately 60% of an individual’s head size, although all species will attempt to consume items up to 100% of head size, often battering them until the less digestible parts have broken away. Food items should be dusted with a suitable calcium/vitamin D3 supplement in at least two out of three feeds. Breeding females may require calcium supplementation at every feed to provide additional calcium for shell formation. In addition to supplementation, a bowl of calcium carbonate powder can be supplied—females will lick the powdered surface if they require additional calcium. Adults should be fed 1−2 times per week and juveniles 3−4 times per week until 3−6 months of age when they can be fed as adults. Dtellas Gehyra species will become obese in captivity if overfed. Adult Dtellas Gehyra and Asian House Geckos H. frenatus are often proactive feeders and rush to meet the keeper at feeding time. They may be handfed using fingers or forceps, or food items may be released into the enclosure.

BREEDING

D FISCHER

In the wild, most Dtellas Gehyra and Asian House Gecko H. frenatus species breed from August to March. The two extralimital Dtellas Gehyra species may breed throughout the year, while northern species will breed as long as environmental conditions support them.

Christinus marmoratus, gravid female

page 160

D BROWN

The breeding strategies of Christinus vary depending on its location. In some populations, eggs are fertilised by sperm that has been stored over winter in special glands in the female’s oviduct— this allows the first clutch of eggs to be laid in spring, before the males are active. The hatchlings subsequently have ample time to grow, boosting the rate of survival in their first winter. Mating in these populations occurs mid-spring, after the first clutches have been laid and once the males have adequately warmed up. Three or more subsequent clutches may be laid in the following months of warmer weather. Other populations lay from early spring to early winter with a break over the hotter summer months. Populations from offshore islands in the extreme south-west of Australia may lay eggs in winter that hatch at the commencement of warmer weather. In captivity, all species in this group breed from August to March. Individuals are capable of reproduction when they reach 60−70% of adult SVL. This should occur between 12−24 months of age, however some smaller species such as the Variegated Dtella G. variegata are not recorded as breeding prior to three years of age. Pair separation is not essential for breeding success and pairs and groups may be maintained together throughout the year. Spermatozoa storage does occur among Asian House Gecko H. frenatus species, with fertile eggs produced 36 weeks after the male’s removal. Cooling should be practiced with species of northern origin. It can be achieved by gradually reducing the number of heating hours and temperatures to the desired winter minimum. A temperature of 15oC−20oC during winter is adequate for Dtellas Gehyra and Asian House Gecko H. frenatus species. Christinus species may need to be cooled to 10oC−12oC, however many will breed without cooling. Courtship among Dtellas Gehyra and Christinus species is poorly described. In Hemidactylus, the male bobs his head and flicks his tongue before slowly approaching the female. He will briefly make a calling sound before circling the female and stopping beside her. Before mating, the male will repeatedly touch the back of the female with his snout and lick her snout.  Mating lasts for at least eight minutes. During mating, the male clasps the female with both pairs of limbs. The first eggs can be expected approximately six weeks after ambient daytime temperatures rise above 25oC for Dtellas Gehyra and the Asian House Gecko H. frenatus and 20oC for Christinus species. A gravid female can be identified by a marked increase in girth. The eggs will be visible through the skin of her abdomen—particularly at night when adults develop pale foraging colours. A typical clutch for these species is 1–2 eggs, although this is not consistent among each genus. The eggs are soft and moist when laid, drying within 15–30 minutes to become hard and brittle. The frequency of egg laying is inconsistent. Some species lay only one clutch comprising a single egg each year, whereas others in the same genus may lay up to six clutches per year. Among those individuals that multiclutch, the interval between clutches is usually 2–3 weeks. Eggs are clearly visible through the abdominal skin of Gehyra robusta

page 161

G SCHMIDA

Hemidactylus frenatus mating

J VOS

W MCKINNON

A gravid Hemidactylus frenatus with an egg visible through its lateral abdomen

A female Gehyra variegata with eggs is revealed under a rock. As this species only lays one egg per clutch, the second egg is from another female

D BROWN

Multiple females may share nest sites in the wild and in captivity. Wild nest sites of the Variegated Dtella G. variegata and the Marbled Gecko C. marmoratus have been recorded containing more than 35 eggs. Whether this is a ‘safety in numbers strategy’ or simply reflects a lack of good nesting sites is unknown. In the wild, most species nest in spaces under rocks, logs and matted vegetation. Other species, such as the Dubious Dtella G. dubia, never lay in direct contact with the ground, instead laying under bark pieces, within gaps in rock slabs or within log hollows. In captivity, nest facilities are easy to provide. Some females will simply lay on top of the sand substrate under pieces of bark. Others will nest in a nestbox containing a mixture of dry sand and coir peat. Nesting sites should be kept dry to avoid the egg spoilage associated with moist sites. A clutch of Gehyra dubia eggs placed between two rock slabs (top piece removed)

page 162

INCUBATION AND HATCHLING DEVELOPMENT Once laid, eggs should be removed for incubation. However, Asian House Geckos H. frenatus and Christinus eggs may be left in the enclosure to hatch—some Dtellas Gehyra eggs can also be left to hatch, although some species will eat freshly hatched young. Incubation should be in a mixture of water and vermiculite at a ratio of 1:3 by weight or 1:30 by volume. Eggs should be incubated at temperatures of 27oC−30oC for Dtella Gehyra and Asian House Gecko H. frenatus species. Christinus eggs respond better to temperatures of 25oC−27oC. At these temperatures, eggs should be incubated for 45−150 days, depending on the species. Eggs incubated at room temperature may need to be incubated for up to 210 days. However, incubation periods often follow no logic and may be more closely associated with factors such as winter egg dormancy.   Negligible swelling occurs during the incubation period. The fertility and viability of the eggs is indicated by their colour. Fertile eggs change from pink to lavender to grey as development progresses, whereas infertile eggs or eggs with early mortality are creamy white. The presence of blood vessels can also indicate fertility if the eggs are candled in the first week or two. Blood vessels are less visible when eggs are candled at a later stage. Egg sweating is not a typical pre-hatch feature among eggs in these species.

BREEDING RECORDS FOR DTELLA AND HOUSE GECKO SPECIES Species

Clutch Interclutch Interval Size (Days)

Egg size (mm) (Mean or Range) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

G. variegata

1

11−45

9.5−12 x 8.5−11

60−65(26oC)

23−25/41−51

G. australis

2

−

12.75 x 10.8

73 (28 C)

29−31 SVL

G. dubia

2

−

12−13 x 9.5−11

75−101 (26 C)

24.5−30/49−60

G. robusta

2

−

11 x 9

−

−

H. frenatus

2

21−28

8.2−10 x 7.2−8.4

46−62 (28 C)

19/39

C. marmoratus

2

−

11−14 x 9−10

70−92 (25oC)

13/28

1−2

−

14.4 x 12.8

91−210 (room)

30 SVL

C. guentheri

o

o

o

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small holding container furnished simply with a small hide—such as a toilet roll or similar—and a water bowl. Most hatchlings are comfortable when kept in a warm room with an ambient temperature of 24oC−28oC. If heating is required, then passive heating from a heat cord or mat is preferred. Food should be offered 24 hours after hatching. Due to the very small size of hatchlings, items should be limited to hatchling crickets, termites or maggots. Once hatchlings begin to grow, items measuring approximately 50% of the hatchling’s head size can be offered. After 12 months, Dtellas Geyhra hatchlings can be fed items measuring 70% of those suitable for adults—Asian House Gecko H. frenatus and Christinus species should wait until 18 months of age to be fed an adult diet. page 163

HYBRIDISATION AND COLOUR VARIANTS Hybridisation and colour variants have not been recorded in these species, despite significant similarities between many Dtellas Gehyra species. ‘Hybridisation’ between chromosomal races of the Marbled Gecko C. marmoratus is possible but as it is impossible to distinguish these visually, it is difficult to avoid. Maintaining locality purity in this species is important.

LONGEVITY

S EIPPER

Longevity records for this group are sparse. The expected life span of most small species is 6−8 years with a productive period of 4−5 years. However, Marbled Gecko C. marmoratus specimens have been recorded surviving to 13 years of age. The expected life span of large Dtellas Gehyra species is 8−10 years with a productive period of 5−7 years. One G. oceanica specimen was recorded surviving to 15.5 years.

ACKNOWLEDGEMENTS I would like to thank those individuals who assisted anonymously with this chapter.

J VOS

Gehyra nana

Gehyra punctata

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G SCHMIDA

Pseudothecadactylus lindneri

GIANT CAVE AND GIANT TREE GECKOS The giant cave and giant tree gecko group comprises three species as follows— Giant Cave Gecko Pseudothecadactylus lindneri Western Giant Cave Gecko Pseudothecadactylus cavaticus Giant Tree Gecko Pseudothecadactylus australis

PRONUNCIATION

DESCRIPTION ADULTS

D BROWN

Following are the accepted pronunciations of the giant cave and giant tree gecko species. Pseudothecadactylus lindneri Sue-doh-theek-ah-dack-til-us lynd-nerr-ee Pseudothecadactylus cavaticus Sue-doh-theek-ah-dack-til-us kav-at-ick-us Pseudothecadactylus australis Sue-doh-theek-ah-dack-til-us os-trah-liss

The giant cave and giant tree group are among the largest geckos in Australia with heavily set features, broad heads and long and slender prehensile tails. The underside of their tail tip has adhesive lamellae similar to that on the underside of their toes—giving them the ability to jump significant distances and land gracefully on uneven surfaces. Members of the Pseudothecadactylus genus have adhesive lamellae on the tip of their tails

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S EIPPER M ANTHONY

Pseudothecadactylus lindneri

They range in size—the smallest species the Giant Cave Gecko P. lindneri measures 96mm SVL. The Western Giant Cave Gecko P. cavaticus and the Giant Tree Gecko P. australis are slightly larger, measuring 115−120mm. A typical specimen measuring an average length of 95mm SVL will weigh an average of 24 grams. Many Giant Cave Geckos P. lindneri are obese and may weigh up to 40 grams. Colouration varies between the three species. Giant Cave Geckos P. lindneri are purple-brown in colouration and may display a strong purplish sheen. They also feature irregular cream, yellow or orange banding, and occasionally spots, from the back of the neck to the hips. The banding is often quite narrow—resulting in brown geckos with yellow stripes—or it can be broad—resulting in yellow geckos with a narrow brown zigzag pattern. Original tails are strongly banded in brown and yellow whereas regenerated tails are a dull brown. Pseudothecadactylus australis

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G SCHMIDA

Pseudothecadactylus cavaticus

JUVENILES Giant Cave Gecko P. lindneri hatchlings are a striking fluorescent yellow, while Western Giant Cave Gecko P. cavaticus hatchlings are only marginally brighter than their parents.       Adult colouration develops from approximately four months of age and is usually attained by eight months of age. Hatchlings are generally 35−40% of average adult size.

A ELLIOTT

S MACDONALD

The adhesive pad on the underside of the tail tip is present on both original and regenerated tails. Considerable variation exists individually. Western Giant Cave Geckos P. cavaticus are superficially similar in colouration to Giant Cave Geckos P. lindneri, except their banding is a more consistent paler cream, often with a dark central area. Giant Tree Geckos P. australis are generally pale brown to olive grey in colouration. They display an obscure pattern of black or dark brown pepperings and mottling based Hatchlings are generally more brightly patterned than around six dark-edged paler blotches on the adults as seen in this Pseudothecadactylus lindneri body and six similar markings on the tail.

Pseudothecadactylus cavaticus juvenile

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D BROWN D BROWN

D BROWN D BROWN

Ventral view of a female Pseudothecadactylus lindneri

Lateral view of a male Pseudothecadactylus lindneri

Lateral view of a female Pseudothecadactylus lindneri

ANON

Ventral view of a male Pseudothecadactylus lindneri

SEXING Giant cave and giant tree geckos are easy to sex during breeding season as adults. Males are generally somewhat larger in size than the females. Adult males display large hemipenal bulges— these may be subtle in juveniles and become less obvious during non-breeding times. Females of these species possess a smaller and sometimes confusing swelling in the same area. Female Pseudothecadactylus lindneri displaying large endolymphatic calcium sacs

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Juvenile males and out of season males may be distinguished from females through a comparison of their paracloacal spurs. In the Giant Cave Gecko P. lindneri, the paracloacal spur clusters comprise 4−6 enlarged scales each 1.5−2 times the size of the adjacent scales—they are situated at the junction between the hemipenal bulge and the upper thigh. Although females possess small spur clusters, individual scales are no more than 1.2 times that of adjacent scales. Hemipenal transillumination can be used on juveniles more than 50% of adult SVL, sub adults and adults, however thick tail scales may make this technique difficult. These species also possess endolymphatic calcium sacs located at the back of the mouth. These are most developed in the breeding season and are usually flat or crescent shaped in males and spherical in females at this time. Juveniles can be reliably visually sexed once they reach 70−75% of adult SVL, which is attained at 9−12 months of age—depending on feeding frequency.

SUBSPECIES The Giant Cave Gecko P. lindneri was once considered to comprise two subspecies—P. l. lindneri and P. l. cavaticus—these have since been separated into distinct species. The Giant Tree Gecko P. australis has no recognised subspecies.

IN THE WILD DISTRIBUTION AND HABITAT

S MACDONALD

Giant cave and giant tree geckos are found in some of the most inaccessible habitats in Australia. The Giant Cave Gecko P. lindneri is found in the massive sandstone escarpments of western Arnhem Land, Northern Territory. Its habitat includes caves and rock crevices—it forages in these and on adjacent fig buttresses. The Western Giant Cave Gecko P. cavaticus is found in the northern Kimberley region of the Northern Territory. Its habitat is similar to that of the Giant Cave Gecko P. lindneri.

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Habitat of Pseudothecadactylus australis, Iron Range, Queensland

The Giant Tree Gecko P. australis is found in the far north of the Cape York Peninsula, Queensland and on the adjacent Torres Strait Islands. Its habitat includes paperbark woodlands, monsoon forests and mangroves. It lives in hollow tree limbs and trunks and forages at night among branches, vines and foliage. If approached during the day it emits a gruff barking sound from within its hollow. Habitat of Pseudothecadactylus australis, Iron Range, Queensland

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Habitat of Pseudothecadactylus lindneri, Nourlangie Rock, Northern Territory

G CALVERT

IN CAPTIVITY STATUS The Giant Gecko P. lindneri has a stable population but it is rather dynamic—at times there are large numbers of these lizards for sale and at other times they cannot be sourced. The Western Giant Cave Gecko P. cavaticus is rare and the Giant Tree Gecko P. australis was unknown in captivity at the time of publication. All three species are poorly known outside of Australia.

HOUSING Giant cave and giant tree geckos are predominantly arboreal and not particular about housing. They are easy to maintain in captivity provided their aggressive nature is catered for by the supply of suitable retreat areas—particularly for the Giant Cave Gecko P. lindneri—to minimise fighting.

INDOOR ENCLOSURES

Pseudothecadactylus australis

M ANTHONY

Suitable enclosures include commercial glass terrariums, timber enclosures and commercial moulded plastic enclosures. These geckos prefer vertical enclosures to horizontal designs. Cave geckos are very dirty by nature and are somehow able to get all of their faeces to land on, and run down, the front glass of an enclosure creating maximum mess. I am yet to own another gecko species with such skills! Regular cleaning is necessary for hygiene reasons and so that you

Pseudothecadactylus cavaticus

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can actually see the cage occupants. Custom built enclosures in which the glass front slopes outwards from top to bottom may encourage faeces to fall away from the glass, keeping it clean. Enclosures should measure a minimum 4−6 SVL long x 4−6 SVL wide x 4−6 SVL high for pairs. Enclosure size will not necessarily affect aggression patterns—I have found furnishings play a greater role in this issue. Suitable substrate is used only to stop faeces from sticking to the floor. Substrate is not important, as these geckos are mostly arboreal—therefore sand, coir peat, leaf litter or gravel may be used. Provide a number of hides in the form of large boxes and vertical slabs of bark on top of each other to counter aggression and behavioural problems. Layered plywood shelters can also be provided. In addition, supply a wall of vegetation in the form of 4−5 stems of artificial foliage hanging vertically on the back walls of the enclosure. There is a particular issue associated with housing Giant Gave Geckos P. lindneri that may be solved or influenced by furnishings in an enclosure. These specimens often develop Floppy Tail Syndrome (see Metabolic Bone Disease on page 116), a disorder also observed in the Rhacodactylus and Uroplatus species, but very rarely in similar Australian Leaf-tailed Gecko Saltuarius species. One of several unproven theories suggests the syndrome is caused by an oversupply of sheer vertical surfaces which place unnatural gravitational forces on the fat tails of well-fed specimens. For this reason the supply of at least a couple of horizontal branches in each cage is important. I am unsure of the validity of this theory. Floppy Tail Syndrome does not occur in all specimens housed similarly and is not recorded in wild specimens which presumably hang in all directions on cave ceilings. I have also seen it in both lean and obese individuals. Whether dietary issues, such as calcium supply and the provision of vitamin D3, play a combined role is unknown. Significant spinal changes similar to scoliosis are noted on radiographs of individuals suffering from this syndrome, as seen with chronic Metabolic Bone Disease. However, these animals breed normally, show no apparent discomfort, do not develop subsequent paralysis issues and do not appear to pass this trait on to their offspring. Enclosures for giant cave and tree geckos should be heated at temperatures that reflect their northern origins. They are tolerant of an enclosure temperature of 24oC−34oC provided for 10−14 hours each day, although I maintain mine at 28oC−30oC. Temperatures above 20oC are adequate in winter. Heat cords or 40W globes can be used for heating. Active cooling during winter is only considered necessary for breeding geckos. Juveniles do not need to be cooled over winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. Access to UV-B light is not essential. If provided, UV-B lamps of 5% or more UV-B are recommended to cater for these species’ tropical origins. Components of a suitable enclosure

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Summary A basic enclosure for giant cave and tree geckos should include the following— • A thin layer of sand substrate on the floor. • Overlapping vertical hides and layers of vegetation to provide numerous hide sites. • An appropriate heat lamp or heat cord providing an enclosure temperature of 28oC−30oC. • A nest box for breeding females—it may be used as a general hide site in the non-breeding season. • A water bowl.

OUTDOOR ENCLOSURES The Giant Cave Gecko P. lindneri is ideally suited to outdoor housing in areas where winter temperatures remain above 10oC at night. Enclosures that have been successful include small suspended aviaries. In cooler areas, larger outside enclosures may be used during summer—they will give occupants more space at a time when they are most aggressive. These are furnished in much the same way as indoor enclosures.

COMPATIBILITY These lizards should be housed as one pair per enclosure. Giant Cave Geckos P. lindneri have been maintained in large outdoor enclosures during summer with Leaf-tailed Geckos Saltuarius without displaying any aggression. The Giant Cave Gecko P. lindneri has a reputation for being, according to some, belligerent, evil, nasty with a capital ‘N’, unpredictable and often irrational. But don’t let this put you off—they are a charming and challenging species. Generally, females are more dominant than males. Aggressive outbursts can occur spontaneously—even after years of peace in established pairs. The ‘issue’ is generally over within a matter of hours—the mate is often injured or killed a few hours after the female begins to display signs of aggression. Occasionally, males may take the initiative and also display aggression. This aggression is generally less of a problem where multiple hide sites are provided. If you recognise early signs of trouble, such as a panicked mate crashing around the enclosure, you should remove the bruised and battered individual before aggression escalates. The victim will often have subcutaneous haemorrhaging around the head and belly from bites. Reintroduction should be approached with extreme caution. Very incompatible pairs can be reintroduced during the winter cooling period on neutral ground or in the enclosure of the battered spouse—this ensures the spouse knows where the hiding spots are first. I spent two years reintroducing a pair of my lizards at intervals of one week in four during the breeding season to allow them to mate before they were separated. It resulted in good breeding outcomes and they are now back together harmoniously—for the time being.

FEEDING In the wild, giant cave and tree geckos feed on insects and spiders and supplement their diet with occasional geckos—particularly Gehyra species. On the odd occasion they will consume frogs. In captivity, they will accept crickets, cockroaches and moths. I have occasionally had specimens consume pinkie mice. Food items should measure up to the size of an individual’s head. Larger items may be accepted but are unnecessary. Juveniles can be fed items 30−50% of their head size. Food items should be dusted with a suitable calcium/vitamin D3 supplement in at least two out of three feeds. page 173

Adults should be fed once a week. The Giant Cave Gecko P. lindneri is particularly at risk of obesity due to its aggressive feeding response and willingness to eat as much as is provided. This may lead to a reluctance to breed. I recommend feeding this species only once a week. Approximately 8−10 food items should be offered per gecko. The Western Giant Cave Gecko P. cavaticus should be fed 2−3 times per week—obesity has not been recorded as an issue in this species. Juveniles should be fed every 3−4 days.

BREEDING

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In the wild, breeding occurs from December to February. In captivity, breeding occurs from July to January. Individuals are capable of reproduction when they reach 70–80% of adult SVL which may occur as early as 12 months of age, but 18 months of age is more common. Pair separation is not essential for breeding success and pairs can be maintained together without problems, unless aggression is noted. Cooling is also unnecessary—the reduction in ambient temperatures in winter is usually adequate for these species. Courtship involves the male chasing the female around the enclosure, vocalising with clicking sounds and head bobbing. Courtship may begin as early as July, however eggs are usually not noted until September or October when enclosure temperatures rise above 26oC. A gravid female can be identified by a marked increase in girth. The eggs will be visible as distinct shapes through the skin of her abdomen. However, they can be easily mistaken for the fat pads that often develop at a similar site—fat pads are usually longer and more symmetrical, whereas the eggs have discrete ends and usually sit slightly overlapped with one in front of the other. A typical clutch for most species in this group is two eggs, although sometimes only one may be laid. The eggs are oval-shaped and leatheryshelled. They are moist when first laid, which can

Eggs are clearly visible through the abdominal skin in this Pseudothecadactylus lindneri

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A gravid female Pseudothecadactylus lindneri at the entrance to its nestbox

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cause the substrate to stick to them. In captivity, up to four clutches may be laid per year, however 1−2 is more typical. The interval between clutches is usually 45−120 days. In captivity, nest facilities are easy to provide and a number of options are suggested by keepers of these species. Most species will lay in elevated containers 2−3 SVL deep—the Giant Cave Gecko P. lindneri favours containers filled with sphagnum moss or a mixture of sand and peat moss, whereas the Western Giant Cave Gecko P. cavaticus A clutch of Pseudothecadactylus lindneri eggs prefers containers filled with sphagnum moss. The females may dig for several days before egg laying, often backfilling their practice holes to make it difficult to ascertain which is the real nest site. Egg fertility is usually quite high in these species, but can be poorer in obese specimens.

INCUBATION AND HATCHLING DEVELOPMENT Once laid, eggs should be removed for artificial incubation. Incubation should be in a mixture of water and vermiculite, or perlite and water, at a ratio of 1:1 by weight or 1:10 by volume. Sphagnum moss may also be used. Incubation is relatively simple and without problems in these species. Eggs should be incubated at temperatures of 28oC−30oC. If non-vented incubation containers are used, egg sweating will precede hatching by 24 hours.

BREEDING RECORDS FOR GIANT CAVE AND TREE GECKO SPECIES Clutch Size

Interclutch Interval (Days)

Egg size (mm) (Mean or Range) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

P. lindneri

2

45−120

24−32 x 7−16

49−61 (29oC−33oC) 55−63 (28oC−29oC)

40−52/74−98

P. cavaticus

2

−

−

61−85 (28oC−30oC)

51−58 SVL

P. australis

2

−

−

−

−

Species

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small holding container furnished with a small hide—usually a toilet roll or piece of bamboo—and a water bowl. Substrate is generally unnecessary. page 175

The enclosure should be maintained at an ambient temperature of 26oC−28oC or may be heated via a heat cord or mat under part of the enclosure. Food should be offered 24 hours after hatching. Initially, items should measure approximately 25−35% of the hatchling’s head size and increase in size to 50−60% after two weeks. Frequent feeding will result in rapid growth rates. However, slow growth rates are preferred as they may minimise the risk of tail deformity. Hatchlings should be maintained individually and only be paired once they reach visible sexing age, but before they attain breeding size—among the Giant Cave Geckos P. lindneri this is at 70% of adult SVL, which is approximately 70−75mm SVL. Ideally, with average growth rates, this should fall inside the winter cooling period when less aggression is likely.

HYBRIDISATION AND COLOUR VARIANTS Hybridisation has not been recorded in these species, however it is possible. There are no known colour variants, although there are variations recorded in the intensity and width of the yellow banding.

LONGEVITY These geckos live relatively long lives. Captive specimens have been recorded living for more than 17 years. One 16-year-old specimen has been recorded as still breeding.

ACKNOWLEDGEMENTS

S MACDONALD

I would like to thank Grant Husband, Rob Porter and Neil Sonnemann, among others, for their assistance with this chapter.  

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KNOB-TAILED GECKOS Nephrurus

D FISCHER

Nephrurus levis occidentalis

The knob-tailed gecko group comprises nine species. Common names can be confusing as the same names have been interchanged between several species within this group in subsequent editions of popular texts. My preferred naming, based on the names that are the most descriptive and relevant to the appearance Nephrurus levis levis of the individuals are— Three-lined Knob-tailed Gecko Nephrurus levis levis—this is derived from the three bands across the base of the head, neck and back. The name Smooth Knob-tailed Gecko is often inappropriately used for this species. West Coast Three-lined Knob-tailed Gecko Nephrurus levis occidentalis Pilbara Three-lined Knob-tailed Gecko Nephrurus levis pilbarensis Smooth Knob-tailed Gecko or Pale Knob-tailed Gecko Nephrurus laevissimus—based on the fact it lacks any significant tubercles on the body and is, therefore, the smoothest species. Pernatty Knob-tailed Gecko Nephrurus deleani Starred Knob-tailed Gecko Nephrurus stellatus Midline Knob-tailed Gecko Nephrurus vertebralis Rough Knob-tailed Gecko Nephrurus asper Central Rough Knob-tailed Gecko Nephrurus amyae Northern Rough-tailed Gecko Nephrurus sheai Banded Knob-tailed Gecko Nephrurus wheeleri page 177

PRONUNCIATION Following are the accepted pronunciations of the knob-tailed gecko species. Neff-roo-rus ay-me-ee Nephrurus amyae Neff-roo-rus ass-per Nephrurus asper Neff-roo-rus dell-ayn-ee Nephrurus deleani Nephrurus laevissimus Neff-roo-rus lay-viss-im-us Neff-roo-rus lev-iss Nephrurus levis Neff-roo-rus shay-ee Nephrurus sheai Neff-roo-rus stell-ah-tus Nephrurus stellatus Neff-roo-rus vur-teb-rah-lis Nephrurus vertebralis Neff-roo-rus wheel-er-ee Nephrurus wheeleri

DESCRIPTION ADULTS Knob-tailed geckos are unique in their morphology. They are of medium size with short bodies. The Three-lined Knob-tailed Gecko N. levis and the Banded Knob-tailed Gecko N. wheeleri have plump, heart-shaped tails that feature a knob at the tip. The Pernatty Knob-tailed Gecko N. deleani, Starred Knob-tailed Gecko N. stellatus, Smooth Knob-tailed Gecko N. laevissimus and the Midline Knob-tailed Gecko N. vertebralis possess narrow tails of moderate length with a terminal knob. The Rough Knob-tailed Gecko N. asper, the Central Rough Knob-tailed Gecko N. amyae and the Northern Rough-tailed Gecko N. sheai have extremely short tails with a terminal knob. They range in size—the smallest species the Starred Knob-tailed Gecko N. stellatus measures 90mm SVL and the largest species the Central Rough Knob-tailed Gecko N. amyae measures 135mm SVL. The majority of species in this group measure 95–110mm SVL. A typical smooth-type specimen measuring an average length of 90mm SVL will weigh an average of 14 grams. A typical rough-type specimen measuring an average length of 105mm SVL will weigh an average of 33.5 grams. Knob-tailed geckos are split into two broad groups—the rough-type knob-tailed geckos and the smooth-type knob-tailed geckos. The rough-type knob-tailed geckos include the Rough Knob-tailed Gecko N. asper, the Central Rough Knob-tailed Gecko N. amyae, the Northern Rough-tailed Gecko N. sheai and the Banded Knob-tailed Gecko N. wheeleri. As the name suggests, these species are adorned with small spines arranged in rosettes creating a rough, prickly body surface. They are reddish-brown to grey-brown in colouration and most are adorned with a fine dark ‘chicken wire’ pattern, particularly on the head. The Banded Knob-tailed Gecko N. wheeleri is variably marked with dark transverse bands. The smooth-type knob-tailed geckos comprise all remaining specimens in this genus. They are generally red-brown, yellow-brown or pinkish in colouration and possess variable amounts of smooth white tubercles scattered in varying patterns.

JUVENILES Hatchlings are similar in colouration and patterning to the adult, although their patterning is often more pronounced when young. The colouration of smooth-type knob-tailed gecko hatchlings may change dramatically over the first few weeks of life, often starting dark and becoming paler with subsequent skin sheds. Rough-type knob-tailed gecko hatchlings often page 178

S MACDONALD

S MACDONALD

Hatchling Nephrurus stellatus

Hatchling Nephrurus wheeleri

display a dark grey or black patch over the back of the shoulders. Hatchlings are approximately 35−40% of average adult size and reach full size at 12 months of age with frequent feeding.

G SCHMIDA

R ERNESTI

Hatchling Nephrurus asper ‘red form’

SEXING Knob-tailed geckos are easy to visually sex as adults. Adult males of all species display hemipenal bulges. These are smaller and have a less defined central depression in females. Hatchling Nephrurus levis levis

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Ventral view of a female Nephrurus amyae

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Ventral view of a male Nephrurus amyae

Ventral view of a male Nephrurus levis

Ventral view of a female Nephrurus levis

Males possess enlarged paracloacal spurs—in males of the rough-type species these spurs are located on conical mounds 3−4 scales high. On top of these mounds are 4−5 slightly pointed scales, twice the size of the adjacent scales. In females, a conical mound just 1−2 scales high is present and the scales on top are, at most, one-and-a-half times the size of the adjacent body scales. In smooth-type species, both sexes possess similar raised mounds, although these are generally smaller than in rough-type species. The mounds are adorned with pointed scales and are roughly twice the size in males than in females. The spurs of male Banded Knob-tailed Gecko N. wheeleri specimens are oval-shaped and comprise 7−8 sharp conical scales 2−3 times the size of the adjacent body scales and similar in size page 180

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Lateral view of paracloacal spurs in a female Nephrurus amyae D BROWN

Lateral view of paracloacal spurs in a male Nephrurus amyae

Lateral view of paracloacal spurs in a male Nephrurus levis

Lateral view of paracloacal spurs in a female Nephrurus levis

to the largest tubercles. In females, the spurs comprise 4−5 blunt conical scales that are at most, one-and-a-half times the size of the adjacent body scales and smaller than the largest tubercles. Juveniles attain these secondary sexual characteristics once they reach 60% of adult SVL which generally occurs at 6−12 months of age with adequate nutrition, depending on the species. Hemipenal transillumination can be used on hatchlings when they reach 40% of adult SVL, however appropriate positioning may make this technique difficult. page 181

G SCHMIDA

Nephrurus levis pilbarensis

SUBSPECIES

G SCHMIDA

Only N. levis and the Banded Knob-tailed Gecko N. wheeleri have recognised subspecies. N. levis is separated into three subspecies—the Three-lined Knob-tailed Gecko N. l. levis found throughout the species range, the West Coast Three-lined Knob-tailed Gecko N. l. occidentalis found on the mid-west coast of Western Australia from Karratha to Geraldton, and the Pilbara Three-lined Knob-tailed Gecko N. l. pilbarensis found exclusively in the Pilbara region and Great Sandy Desert in Western Australia. Distinguishing between each subspecies is considered straightforward from a taxonomic

Nephrurus wheeleri cinctus

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S EIPPER

Nephrurus wheeleri cinctus

point of view, however it is a nightmare for most gecko enthusiasts. The typical features of these subspecies can be subjective and inconsistent, even with the aid of magnification and highquality imagery. The most reliable method of distinguishing between them is to compare the labial scales and throat granules. Comparison of the rostral/mental scale is particularly unreliable. The following table may assist. Feature

N. l. levis

N. l. occidentalis

N. l. pilbarensis

Throat granules

Homogenous

Homogenous

Some large granules scattered among smaller ones

Rostral scale size

Equal to mental scale width

Narrower than mental scale

−

Labial scale size

First upper labial scale equal to or deeper than second

Second upper labial scale deeper than first

−

Neck lines

Obvious

Often pale or obscure

Obvious

Body tubercles

Medium size

Very small

Medium size but fewer

Body pattern

Scattered tubercles with variable pattern, other markings less prominent

Tubercles abundant but very small

Less tubercles particularly on the tail, other markings more prominent

Tail shape

Heart-shaped

Tail broader and depressed

Heart-shaped with fewer tubercles

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Nasal scalation of Nephrurus levis levis showing rostral scale (R) equal to mental scale (M) and 1st upper labial (1) equal or deeper than 2nd upper labial (2)

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Throat granules of Nephrurus levis pilbarensis displaying scattered larger scales, particularly concentrated near the edges of the throat D BROWN

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Throat granules of Nephrurus levis levis and Nephrurus levis occidentalis displaying homogenous scalation

Nasal scalation of Nephrurus levis occidentalis showing rostral scale (R) narrower than mental scale (M) and 2nd upper labial (2) deeper than 1st upper labial (1)

The Banded Knob-tailed Gecko N. wheeleri is separated into N. wheeleri wheeleri and N. wheeleri cinctus. N. w. wheeleri is found in Acacia woodlands and shrublands on stony soils in the Murchison district of Western Australia. It usually has four variable bands on the body—one each on the rump, the tail base, the tail tip and on the neck and shoulder area. N. w. cinctus is found on rocky Spinifex country in the Pilbara region of Western Australia. It usually has five bands—one each on the neck, the shoulder, above the rump, at the tail base and on the tail tip. Unfortunately, the development of colour morphs in the Banded Knob-tailed Gecko N. wheeleri has modified the position of these bands, rendering these features less than helpful when trying to distinguish captive specimens. page 184

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Significant colour variation in the Rough Knobtailed Gecko N. asper can make identification of this species difficult to distinguish from other roughtype knob-tailed geckos—particularly when comparing the Central Rough Knob-tailed Gecko N. amyae with the red form of the Rough Knobtailed Gecko N. asper. The main difference lies in the length and sharpness of the tubercle spines over the tail base, which are larger and sharper in the Central Rough Knob-tailed Gecko N. amyae. The Starred Knob-tailed Gecko N. stellatus is often considered to include an ‘eastern’ population with a dark head and dark neck stripes and a ‘western’ population with the head and neck the same as the body colouration elsewhere. These have not been allocated subspecies status.

IN THE WILD

Comparison of the tail spines of Nephrurus amyae (top) and Nephrurus asper ‘red form’

DISTRIBUTION AND HABITAT

Habitat of Nephrurus levis occidentalis, Monkey Mia, Western Australia

D FISCHER

Knob-tailed geckos are distributed across much of Australia, excluding along the southern and south-eastern coastlines. Rough-type knob-tailed geckos inhabit stony areas—they are not generally a burrowing species. Smooth-type knob-tailed geckos inhabit sandy country with grassland cover such as Spinifex. At night, they venture from their burrows or from hollows under rocks or logs to forage over the surface of the ground.

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D FISCHER D FISCHER

D BROWN

Habitat of Nephrurus wheeleri, Cue, Western Australia

Habitat of Nephrurus levis levis, Windorah, Queensland

Habitat of Nephrurus amyae, Glen Helen, Northern Territory

Collectively, the knob-tailed gecko group is exposed to some of the harshest climatic conditions in Australia—daytime temperatures exceed 45oC in summer and winter temperatures fall below freezing at night. They cope with this by altering the depth of their burrows or the size and depth of the rocks under which they reside. page 186

J VOS

IN CAPTIVITY

S EIPPER

Nephrurus levis pilbarensis

STATUS Knob-tailed geckos are fast becoming the most popular geckos kept in Australia. They are hardy, easy to care for and have an endearing nature that makes them an ideal beginner’s gecko. N. levis and the Central Rough Knob-tailed Gecko N. amyae are the most commonly Nephrurus amyae kept species, representing 60−70% of specimens in captivity. The other species are kept in much lower numbers, partly because they are more difficult to keep and breed and also because many have originated from a very small pool of founder stock and are still being established. Knob-tailed geckos are popular overseas.

HOUSING Knob-tailed geckos are entirely terrestrial and among the easiest geckos to maintain in captivity— they are ideal for beginners. Specific housing requirements vary between smooth-type and rough-type species, with the greatest differences noted in substrate and furnishings. page 187

INDOOR ENCLOSURES

D BROWN

Suitable enclosures include plastic terrariums, fish tanks, commercial terrariums and plastic tubs. Rack systems may also be used—using clear containers allow eggs to be viewed easily through the bottom. Enclosures should measure a minimum of 4−5 SVL long x 3−4 SVL wide x 2−3 SVL high. They do not need to be excessively large, as these geckos use space well. Larger enclosures give occupants more mobility but also make it harder for them to catch their food. Enclosure height is not important, as these species are entirely terrestrial and unable to climb smooth surfaces. As with all terrestrial species, the choice of substrate in an enclosure is important. Suitable substrate is sand—particularly red desert sand, plasterer’s sand or washed beach sand. The key is to use sand that clumps together well when moist but is not sticky and loose when dry. Avoid sands with clay content such as brickies’ loam. Some keepers also maintain these species on paper towel with burrowing opportunities provided in moist hide boxes. Smooth-type knob-tailed geckos are burrowers and an enclosure should cater for this need. Burrowing facilities may be supplied in one of two ways—direct sand burrowing or through the use of a moist hide. The option you select will depend on your personal management style and facilities. When accommodating direct sand burrowing, include sand of varying depths. Sand at a depth of 2cm is suitable at the shallow, dry end of the enclosure and a depth of 5−10cm is suitable at the deeper, moist end, where burrows are likely to be established. The provision of an artificial roof support, such as an upturned terracotta or plastic saucer, will improve stability. Highly-strung species, such as the Starred Knob-tailed Gecko N. stellatus and the Smooth Knobtailed Gecko N. laevissimus, appear to prefer sand at least 15cm deep to allow for deep burrowing, although some breeders only supply this deep burrow option to egg laying females. Juveniles cope well with shallower substrates. When a smooth-type knob-tailed gecko commences burrowing it will often lick the sand at the entrance of the burrow site before burrowing, presumably to check for prior residence. Once the burrow has been dug, the gecko will then push sand back up and into the burrow, plugging

Nephrurus wheeleri often toss dry sand on their backs and head as camouflage

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the hole at ground level to exclude predators and retain humidity. Captive animals using artificial sites, such as saucers or plastic tubs, will also do this. Moist hides measuring 2−3 SVL long x 2−3 SVL wide x 2 SVL high can be used in enclosures for smooth-type knob-tailed geckos if a large amount of heavy sand cannot fit. Hides can be in the form of a plastic container—the inside should be painted dark and the container inverted, making the lid the container floor. Cut an entrance hole part way up the side and bury the box partially in the sand—the hole should be almost level with the sand surface. These hides will provide specimens with a burrowing site and the rest of the enclosure has just 1−2cm of sand cover. Occupants will be drawn to this site to lay eggs and burrow if it is the only moist sand in the enclosure. All that is required in the remainder of the enclosure is a dry hide and a water bowl. Rough-type knob-tailed geckos are not burrowers. They may be maintained in a similar enclosure, but will not require subsoil moisture or deep sand for burrowing—2cm deep is ideal. These species will use the sand for additional camouflage, tossing it on their back—this behaviour is most noticeable among Banded Knob-tailed Gecko N. wheeleri specimens. Rough-type species may dig a shallow scrape in the sand under a flat surface. Provide an upturned terracotta saucer with a door cut in it, a terracotta pot cut in half lengthwise or an opaque container. One hide per gecko is recommended. Provide rocks, rock slabs or logs throughout the remainder of the enclosure, but be aware of the risk of them collapsing on occupants if they attempt to burrow under them. If they are to be used, they must be partly buried and sit directly on the enclosure floor and not on the sand surface. Heating these species is simple. A substrate temperature of 28oC−30oC for 10−14 hours per day is ideal—this should be reduced to 20oC−22oC at the cool end of the enclosure. A hide should be provided at the hot and cold ends of the enclosure. A moist hide can be placed at either end—I place mine at the cooler end of the enclosure, the reasoning being that in the wild, burrowing occurs from the warmer surface to the cooler subsurface, therefore burrowing in a heated box is less natural. Heat mats, heat cord or incandescent bulbs can be used for heating. I recommend heat mats and cords because of the nocturnal nature of these species. Heat provided by light bulbs is less ideal—they are limited in the amount of heat available and knob-tailed geckos will generally avoid bright lights, although red globes can be used. Heating the air in the enclosure is of little value to a burrowing species unless the sand is somehow able to retain the heat. Bulbs also dry the sand faster, resulting in poor burrow stability. Heat can be reduced during winter to 15oC–20oC. I recommend using a thermostat to achieve this. In my collection I use a thermostat on the heat cords. Active cooling during winter is only considered necessary for breeding geckos. Juveniles do not need to be cooled during winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. The provision of UV-B light is not essential for these species, although it may benefit juveniles and breeding females. UV-B lamps of 5% or more UV-B are ideal. It may not be required if adequate calcium and vitamin D3 is provided through the diet. Ventilation should only be a concern when rack systems are used. A major challenge with these systems is balancing soil moisture with appropriate ventilation. Excessive ventilation will allow the sand to dry, whereas insufficient ventilation will result in condensation that will ultimately damage the shelving above the enclosure and encourage mould to grow on shelf surfaces. If containers are used, condensation usually occurs within the moist hide. A bowl of water should always be supplied. Alternatively, the enclosure can be sprayed twice a week with water. page 189

D BROWN

Summary

D BROWN

Components of a suitable enclosure for smooth-type knob-tailed geckos—direct burrowing enclosure

Components of a suitable enclosure for smooth-type knob-tailed geckos—shallow sand enclosure D BROWN

A basic enclosure for smooth-type knob-tailed geckos should include the following— • Part of the substrate should have sufficient moisture and a depth of 10−15cm to support burrowing. Include a supporting hide site to act as a ‘roof’. Alternatively, supply a container of moist sand. The remainder of the enclosure can be covered with a layer of dry sand at least 2cm deep. • A dry hide, such as an upturned terracotta pot or plastic saucer. • Underfloor heating with a warm end 28oC−30oC and a cool end 20oC−22oC. • A water bowl. A basic enclosure for rough-type knob-tailed geckos should include the following— • A substrate of sand 2−3cm deep. • Dry hides, such as an upturned terracotta pot or plastic container placed in the warm and cool areas of the enclosure. • A moist nest box at nesting time. • Underfloor heating with a warm end 28oC−30oC and a cool end 20oC−22oC. • A water bowl.

OUTDOOR ENCLOSURES I am aware of various knob-tailed gecko species being kept in outdoor enclosures within their natural range. As burrowers or cryptic species they may only be observed when active at night and thus make a poor outdoor enclosure occupant. Components of a suitable enclosure for rough-type knob-tailed geckos

page 190

COMPATIBILITY Knob-tailed geckos are generally placid towards each other and usually only display aggression when there is a significant size disparity between specimens. They can be housed in pairs or trios with one male per enclosure. Females are the more aggressive sex, as they are invariably larger in size and more dominant. I have experienced personal success with smooth-type specimens housed as pairs or trios— particularly one male with two females—but better results with only pairs of rough-type species. Some keepers prefer to house these geckos individually and only introduce them for breeding purposes. Particular problems are noted among the Smooth Knob-tailed Gecko N. laevissimus, the Pernatty Knob-tailed Gecko N. deleani and the Starred Knob-tailed Gecko N. stellatus that might be related to the numbers held in an enclosure. These species are well known for being highlystrung, finicky and unpredictable. They appear to do well for extended periods of time but can begin to lose weight and cease eating—a significant problem in Australia as opposed to overseas where they are significantly more robust and considered to have the same requirements as N. levis. In Australia, theories concerning the poor viability of these populations may include the prevalence of recently wild caught individuals, inbreeding in captive bred stock or inappropriate husbandry. However, these theories do not explain why some populations do exceptionally well and others fail. Overseas, their viability might be explained by the breeding out of undesirable traits many years ago. Maintaining individuals separately and only introducing them for breeding purposes could be a solution and has resulted in fewer issues.

FEEDING Knob-tailed geckos feed on spiders, scorpions, centipedes, cockroaches, crickets, moths and any other arthropods that come within reach. They also readily consume other lizard species— particularly other geckos. They feed by chasing food items spotted from a distance, but will also sit and wait for prey to pass by to ambush. In captivity, they will accept pinkie mice and any terrestrial insect including crickets and cockroaches, which they consume in equal amounts. More so than in other gecko species, they can become bored if fed only one type of food. I provide a diet of crickets but also include mid-sized wingless cockroaches for females after egg laying—it appears to help them regain condition faster than on a diet of only crickets. Pinkie mice will also help females regain condition, particularly in large species such as the Central Rough Knob-tailed Gecko N. amyae—a large female can eat 2−3 pinkie mice in one sitting. Food item size should measure approximately 60% of an individual’s head size. Food items should be lightly dusted with a suitable calcium and vitamin D3 supplement in at least two out of three feeds.   Adults should be fed every 4−7 days in summer and every 7−10 days in winter, although they may not accept food for short periods during this time. Juveniles should be fed every 2−4 days throughout the year. Dominance problems can be alleviated by feeding each individual 4−6 food items per feed. Water is always supplied in bowls, although some keepers utilise twice weekly water sprays as an alternative means of supplying water. page 191

BREEDING

R ERNESTI

In the wild, breeding occurs from October to March. In captivity, breeding occurs from September to March, although if constant breeding conditions are supplied, these species may breed for nine months of the year. In the wild, N. levis are capable of reproduction when they reach 62mm SVL for males and 71mm SVL for females. Smooth-type knob-tailed geckos are capable of reproduction when they reach 7−12 months of age. However, the Smooth Knob-tailed Gecko N. laevissimus, Pernatty Knob-tailed Gecko N. deleani and the Starred Knob-tailed Gecko N. stellatus may delay breeding until 12−18 months. Rough-type knob-tailed geckos mature much slower and are capable of reproduction when they reach 15−24 months of age. However, I have observed the Central Rough Knob-tailed Gecko N. amyae breeding successfully at 114mm SVL at 10 months of age. It is generally advisable to delay breeding until specimens are more mature, as fertility in the first season may be poor. The best breeding results generally occur in the second and subsequent breeding seasons.   Pair separation is not essential for breeding success and pairs may be maintained together throughout the year. Out of season breeding is rare—females can rest in the non-breeding period in the presence of males. Some breeders prefer to separate sexes and only introduce them for breeding. This makes little difference for most species, but it may be important for highly stressed species including the Starred Knob-tailed Gecko N. stellatus, the Smooth Knob-tailed Gecko N. laevissimus and the Pernatty Knob-tailed Gecko N. deleani. Some male Central Rough Knob-tailed Geckos N. amyae and Rough Knob-tailed Geckos N. asper benefit from separation from the females in the nonbreeding season as they become ‘hen pecked’ and may lose weight. If cooling is practiced, it can be achieved by supplying temperatures of 15oC−20oC during the day and temperatures of 12oC−15oC during the night. However, active cooling is not essential and I do not practice it, as my local ambient temperature changes are sufficient. Courtship involves the male licking the ground around the female and then licking her. The female then lifts her tail and waves it side-to-side before extending it over her back to expose

Nephrurus levis levis mating—a Normal male and a Patternless female, note the typical size difference between the males and the females

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D BROWN

R ERNESTI

her cloaca to the male. Sometimes the female will initiate the courtship with this display. The male will then either lick the cloaca or grasp the female by the back of her neck, positioning himself on top of her, but with his tail tucked under the female’s tail. Mating may last an hour or more. It is generally not observed among the more secretive roughtype species but can be observed in the smoothtype knob-tailed gecko species. The first eggs can be expected 4−6 weeks after ambient daytime temperatures rise above 20oC or three weeks after the male is introduced during optimum temperatures. A gravid female can be identified by a marked increase in girth. The eggs will be visible as distinct shapes through her abdominal wall—particularly in smooth-type species. A typical clutch for species in this group is two Eggs are clearly visible through the abdominal eggs, although sometimes only one will be laid. skin of Nephrurus levis The eggs are oval-shaped and leathery-shelled. They are moist when first laid, which can cause the substrate to stick to them. In captivity, females generally produce up to five clutches per season, although extremely productive females can produce up to 10 clutches. Rough-type species often lay fewer clutches per year, with 3−4 as typical. The interval between clutches is usually 2.5−8 weeks, with interclutch intervals longer in rough-type species. In captivity, nest facilities are easy to provide and most species will happily lay in a moist corner of the enclosure. Some breeders prefer to utilise moist Nephrurus sheai depositing eggs in a nesting hides for nesting by cutting an entrance hole in the burrow side and burying them in dry sand up to the bottom of the nestbox entrance hole. It can be difficult to predict when female smooth-type knob-tailed geckos will lay their eggs, as they may use these moist hides or sand for nesting and day-to-day burrowing. In comparison, rough-type knob-tailed geckos only dig burrows in moist sand for one purpose—to lay eggs. Both gecko forms will usually dig test holes a couple of days before laying their eggs. The eggs are generally laid on the bottom of the enclosure or nesting container and are usually visible through the bottom of clear containers, allowing for easy egg recovery.

INCUBATION AND HATCHLING DEVELOPMENT Once laid, eggs should be removed for artificial incubation. Incubation should be in a mixture of water and vermiculite or perlite at a ratio of 1:1 by weight or 1:10 by volume. Incubation is relatively simple and without problems in these species. A standard non-vented container may be used. Eggs should be incubated at temperatures of 28oC−29oC. page 193

J LUKE

Considerable egg expansion occurs during incubation with increases of up to 40% in width and 25% in length common. Incubation periods for smooth-type knob-tailed geckos are generally shorter than those of roughtype knob-tailed geckos incubated at the same temperature. There seems to be little differences in egg parameters between the Three-lined Knob-tailed Gecko N. l. levis, the West Coast Three-lined Knobtailed Gecko N. l. occidentalis and the Pilbara Threelined Knob-tailed Gecko N. l. pilbarensis. There is some anecdotal evidence to suggest A hatchling Nephrurus amyae these species are a temperature dependent sex determination group. Eggs incubated at 25oC−29oC produce an equal ratio of males and females. Eggs incubated at temperatures below 25oC result in more females. Upper temperature levels remain untested, as few keepers incubate eggs above 29oC. These geckos are believed to be Type Three TSD. If non-vented incubation containers are used, egg sweating will precede hatching by 24 hours.

BREEDING RECORDS FOR KNOB-TAILED GECKO SPECIES Interclutch Egg size (mm) Interval (Mean or Range) (Days) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

Species

Clutch Size

N. levis

1−2

17−61

24−27.0 x 11.5−15

57−70 (27oC−29oC)

39−41/ 56−59

N. laevissimus

1−2

14−36

17−20.5 x 9−12.5

75−85 (23oC−24oC) 57−67 (27oC−29oC) 50−60 (30oC−32oC)

32−36/ 44−50

55−56 (29oC−30.5oC) 59.5 (average 30 oC) (28oC)

36−38/ 51−54

N. deleani

1−2

27−43

20.7−25.4 x 11.4−13.4

N. amyae

1−2

22−60

29−37.4 x 16−20

77−94 (28oC−29oC) 115 (25oC)

48/58

N. asper

1−2

22−58

26.2−31 x 15.1−17.2

77−100 (28oC) 115−130 (21oC−31oC)

40−46.4/ 52−57

N. stellatus

1−2

19−36

16−24 x 10−14

52−66 (28oC)

20−22/30

N. sheai

1−2

−

29−30 x 15.5−16.5

115 (25oC) 63 (29oC)

48.1−51.1/ 56.7−59

N. wheeleri

1−2

21−42

33 x 9.0−11

60−61 (29.8oC) 67−78 (28oC)

35/52

page 194

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small holding container furnished with a small hide—such as a toilet roll cut lengthwise or similar—and a water bowl. I prefer to put Nephrurus hatchlings directly on to a thin layer of desert or beach sand substrate, as they are more comfortable on this than on bare floors or paper towel. Heating may be provided by a small heat pad or by maintaining them in a room with an ambient temperature of 26−28oC. Food should be offered 24 hours after hatching. Initially, items should measure approximately 40% of the hatchling’s head size and be increased to 50−60% in size after two weeks. Suitable food items include small crickets and small cockroaches. Frequent feeding will result in rapid growth rates, with some individuals reaching adult size before 12 months of age. Juveniles should be maintained individually to avoid dominance problems at feeding time.

HYBRIDISATION AND COLOUR VARIANTS Hybridisation has not been widely recorded in these species in Australia, however there is potential for this between the N. levis subspecies—a real concern and threat to their purity. Unfortunately, numerous hybrids occur overseas and can be difficult to tell apart from pure specimens. Subspecies must be maintained separately where possible. I am aware of a N. asper x N. amyae hybrid that subsequently laid eggs that were not fertile. A number of selected colour morphs have been established in Australia and overseas—where the majority occur. Hypomelanistic N. levis specimens have been found in the wild and some have been established in captivity. They are sometimes referred to as ‘Ruby’ N. levis and appear brighter in colour than normal specimens. Their black areas are replaced with pale lavender-grey. This mutation appears to be recessive in its mode of inheritance. Patternless specimens of the Three-lined Knob-tailed Gecko N. l. levis have also been observed but are not well established in captivit y. These spectacular lizards display no markings except for a pale dorsal midline stripe. They are often referred to as ‘Jellybean levis’ due to their similarity at hatchling age to a pink jellybean. This mutation appears to be recessive in its mode of inheritance. A similar mutation has been recorded in the Pilbara Three-lined Knob-tailed Gecko N. l. pilbarensis in overseas collections, where they are referred to as a ‘Skunk stripe’ mutation. The Striped Three-lined Knob-tailed Gecko N. l. levis is established overseas. In this mutation the pale stripes run lengthwise rather than transversely across the body. The Albino Pilbara Three-lined Knob-tailed Gecko N. l. pilbarensis has become well established since the first was hatched in the USA in 1995. This mutation appears to be recessive in its mode of inheritance. The albino gene has been combined with other mutations including the Patternless. A recent mutation in the West Coast Three-lined Knob-tailed Gecko N. l. occidentalis, developed by Sarah Ransom, is the leucistic, or ‘translucent’, mutation. In this mutation, the deeper skin tissue is unable to retain pigment, including white pigment, resulting in a near patternless specimen with see-through skin—particularly ventrally, with all internal organs clearly visible through the ventral skin. The mode of inheritance appears to be recessive. An amelanistic Pilbara Three-lined Knob-tailed Gecko N. l. pilbarensis has recently been observed in Australia. Other N. levis and Smooth Knob-tailed Gecko N. laevissimus colour morphs are due to selective breeding of outstanding colour forms such as bright shades of orange, yellow or red or—in the case of the Pilbara Three-lined Knob-tailed Gecko N. l. pilbarensis—selection of specific dorsal patterning. page 195

D BROWN J LUKE

D WONG

Leucistic Nephrurus levis occidentalis

Patternless ‘Jellybean’ Nephrurus levis pair

Hypomelanistic Nephrurus levis

The Central Rough Knob-tailed Gecko N. amyae displays considerable variation in colour on a daily basis, becoming pale at times. A limited number of true hypomelanistic Central Rough Knob-tailed Gecko N. amyae exist—they are cream in overall colour. Rough Knob-tailed Geckos N. asper display considerable variation in colour in the wild—these colour forms also exist in captivity. The most common is the plain grey-brown form. Also present in small numbers are red forms from the Mount Isa and Dajarra regions of Queensland, and heavily striped forms from the north Queensland tablelands and Cape York. N. w. cinctus has been bred overseas for many years and is available in a variety of designer colour morphs including a loss of bands (Patternless), longitudinal bands (Striped) and zigzag banding (‘flame’ wheeleri). page 196

D BROWN D WONG

Yellow Nephrurus levis occidentalis

Patternless Nephrurus levispilbarensis

page 197

D WONG D WONG

Patternless Albino Nephrurus levis pilbarensis

C TUCKER

Albino Nephrurus levis pilbarensis

LONGEVITY Knob-tailed geckos live relatively long lives. The average life span of smooth-type species is 7−8 years with a productive period of 4−6 years. The average life span of roughtype species is 9−11 years with a productive period of 6−8 years. Exceptional specimens have been recorded to live longer. A Central Rough Knob-tailed Gecko N. amyae was collected on licence as an adult in 1997 and was still alive in my collection and breeding in 2008.

ACKNOWLEDGEMENTS I would like to thank Rob Porter, Byron Manning, Terry Morley, Manfred Au, Simon Treseder, Ryan Ernesti, Dr Gavin Bedford, Clark Tucker, Derek Wong, Sarah Ransom and Ken Bartenfield, among others, for their assistance with this chapter.

Striped ‘Flame’ Nephrurus wheeleri

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G SCHMIDA

Saltuarius swaini

LEAF-TAILED GECKOS

This group comprises 16 species in three genera as follows— Northern Leaf-tailed Gecko Saltuarius cornutus Kate’s Leaf-tailed Gecko Saltuarius kateae Moritz’s Leaf-tailed Gecko Saltuarius moritzi Rough Throated Leaf-tailed Gecko Saltuarius salebrosus Southern Leaf-tailed Gecko Saltuarius swaini Wyberba Leaf-tailed Gecko Saltuarius wyberba Riverine Leaf-tailed Gecko Phyllurus amnicola Ringed Thin-tailed Gecko Phyllurus caudiannulatus Champion’s Leaf-tailed Gecko Phyllurus championae Gulbara Leaf-tailed Gecko Phyllurus gulbara Mount Jukes Broad-tailed Gecko Phyllurus isis Oakview Leaf-tailed Gecko Phyllurus kabikabi Peppered-belly Broad-tailed Gecko Phyllurus nepthys Mount Ossa Broad-tailed Gecko Phyllurus ossa Broad-tailed Gecko Phyllurus platurus McIlwraith Leaf-tailed Gecko Orraya occultus

PRONUNCIATION Following are the accepted pronunciations of the most common members of the Leaf-tailed gecko species. Saltuarius cornutus Sal-chew-air-ee-us core-new-tus Saltuarius moritzi Sal-chew-air-ee-us more-it-zee Saltuarius salebrosus Sal-chew-air-ee-us sal-ee-bro-sus Saltuarius swaini Sal-chew-air-ee-us sway-nee Saltuarius wyberba Sal-chew-air-ee-us why-burr-bah Phyllurus caudiannulatus Phil-oo-rus cord-ee-ann-you-lah-tus Phyllurus platurus Phil-oo-rus plat-oor-us page 199

D FISCHER G SCHMIDA

Saltuarius cornutus

Saltuarius salebrosus

page 200

D BROWN D FISCHER

Saltuarius moritzi

Saltuarius swaini

page 201

G SCHMIDA A ELLIOTT

Saltuarius wyberba

Phyllurus amnicola

page 202

D FISCHER

S EIPPER

D FISCHER

Phyllurus gulbaru

Phyllurus ossa

S EIPPER

Phyllurus caudiannulatus

Phyllurus nepthys

page 203

S MACDONALD

Phyllurus platurus

DESCRIPTION ADULTS

D BROWN

D BROWN

The leaf-tailed gecko group are among the largest geckos in Australia with spectacular, ornate and distinctive leaf or heart-shaped tails from which these species get their name. However, many specimens have pale grey-green regenerated tails that lack the ornate surface features or fringing of the original tail. The two primary genera can be distinguished by the shape of their original tail. Saltuarius tails are broad and flat with elaborate fringing and Phyllurus tails are cylindrical or flat with a simple flared edge. Their rostral scale arrangements also vary—Saltuarius have the rostral scale contacting the nostrils, whereas in Phyllurus the rostral scale is separated from the nostril by additional scales.

Saltuarius cornutus nose tip with rostral scales contacting the nostrils

Phyllurus platurus nose tip with rostral scales not contacting the nostrils

page 204

D BROWN

D BROWN

D BROWN

Phyllurus platurus tail with simple edge fringing

Saltuarius cornutus regenerated tail lacking tubercles or fringing

Phyllurus caudiannulatus with a long, thin tail

They range in size—the smallest species the Mount Jukes Broad-tailed Gecko Phyllurus isis measures 76mm SVL and the largest species the Northern Leaf-tailed Gecko Saltuarius cornutus measures 144mm SVL. The majority of species in this group measure 90–130mm SVL.   A typical specimen measuring an average length of 125mm SVL will weigh an average of 28−30 grams. Colouration is generally grey-green, brown or green and they are superbly camouflaged with lichen-like flecks and fine surface protuberances that allow them to blend in with the environment—they can even be difficult to observe in a small enclosure.

D BROWN

S MACDONALD

Saltuarius salebrosus tail with elaborate edge fringing

Saltuarius salebrosus, master of camouflage

page 205

S EIPPER D BROWN

Hatchling Saltuarius swaini

Hatchling Saltuarius salebrosus

JUVENILES Hatchlings are a brighter version of the adult in colouration and patterning, but dull in appearance over 6−9 months. They are generally 30% of average adult size at hatching and reach adult size at approximately 24−36 months of age. page 206

D BROWN D BROWN

D BROWN

Ventral view of a female Saltuarius salebrosus

D BROWN

Ventral view of a male Saltuarius salebrosus

Ventral view of a male Phyllurus platurus

Ventral view of a female Phyllurus platurus

SEXING Leaf-tailed geckos are easy to visually sex as adults, although there are no visible differences in the colour, size or patterning of males and females. Adult males display obvious large hemipenal bulges. They are visible as swellings in juveniles when they reach 60−70% of adult SVL, which is attainable at 9−18 months of age, depending on feeding frequency and species—Saltuarius generally have slower growth rates. page 207

SUBSPECIES Leaf-tailed geckos have been subject to much taxonomic confusion for many years. All species were initially described as members of the Phyllurus genus. They were then separated into two Phyllurus and two Saltuarius species with numerous variations along the east coast of Australia. Over time each locality has had its own species described—undoubtedly more will follow. At the time of publication, nine Phyllurus, six Saltuarius and one Orraya species are described. There are no recognised subspecies within the current species.

IN THE WILD DISTRIBUTION AND HABITAT

D BROWN

Leaf-tailed geckos are distributed along the east coast of Australia from Sydney, New South Wales, to Cooktown, Queensland. Habitat is limited to either rainforest or large granite outcrops. Many species are restricted exclusively to isolated rainforest habitats on single mountain ranges. Others occur across several widely distributed sites but are oddly absent from similar habitat in adjacent areas. This is often the case with large granite outcrop species. They may be absent from these other rocky areas due to the absence of particular microclimates within the habitat rather than inadequacies in the physical features of the habitat. This may be why many species are restricted to habitats in elevated, cooler localities but are absent from suitable habitat in warmer lowland localities. Refer to the table opposite outlining a summary of the habitat use and distribution of various species.

Habitat of Saltuarius salebrosus, Blackdown Tableland National Park, Queensland

page 208

HABITAT AND DISTRIBTUION OF LEAF-TAILED GECKO SPECIES Species

Habitat preference

Locality

P. amnicola

Rainforest with granite boulders (elevation 400−1000m)

Mt Elliot, Townsville, Queensland

P. caudiannulatus

Dense rainforest

Bulburin State Forest, central Queensland

P. championae

Rainforest with granite boulders

Cameron Creek and Blue Mountain, central Queensland

P. gulbara

Rainforest with Hoop Pine and granite boulders

Southern Paluma Range National Park, Queensland

P. isis

Rainforest with mossy rock understorey

Mount Blackwood and Mount Jukes, Mackay, Queensland

P. kabikabi

Vine thicket with granite boulders

Oakview State Forest, south-east Queensland

P. nepthys

Rainforest

Eungella National Park and Clarke Range, Mackay, Queensland

P. ossa

Rainforest with granite boulders

Mount Ossa/Mount Charlton, Mackay, and Mount Dryander/Conway Range, Proserpine, Queensland

P. platurus

Sandstone outcrops/caves

Sydney sandstone basin, New South Wales

S. cornutus

Rainforest

Cooktown to Mount Spec, north Queensland

S. salebrosus

Granite outcrops, sandstone cliffs, rainforest

Blackdown Tableland National Park to Cracow, central Queensland; Carnarvon National Park, western Queensland; Bania and Bulburin State Forest (rainforest forms), central Queensland

S. swaini

Rainforest

Bulahdelah, New South Wales, to Mount Tamborine, south-east Queensland

S. wyberba

Granite outcrops

Girraween National Park, New South Wales, and Stanthorpe, south-east Queensland

S. kateae

Sandstone escarpments in open forest

Mount Marsh and Wyans Creek, New South Wales

S. moritzi

Wet sclerophyll forest, rock escarpments

Bulahdelah to Coffs Harbour, New South Wales

O. occultus

Granite boulders in rainforest

Peach Creek, McIlwraith Range, Queensland

page 209

D FISCHER

D FISCHER

Habitat of Saltuarius wyberba, Girraween National Park, Queensland

Habitat of Saltuarius swaini, Lamington Plateau, Queensland

Behaviour varies throughout the day. During daylight these geckos can be found in deep crevices between large granite boulders or within the complex buttress root systems of large fig trees. At night they move out onto the surfaces of rocks or tree trunks. They can generally be observed in a head-down posture between 30cm and four metres from the ground. Leaf-tailed species are often active at much lower ambient temperatures than other gecko species. The Wyberba Leaf-tailed Gecko Saltuarius wyberba has been observed active at night at temperatures of 10.5oC. Minimum temperatures in the natural range of this species generally reach -8oC.

IN CAPTIVITY STATUS

S MACDONALD

Leaf-tailed geckos are not held in high numbers in Australia. Of the 15 Saltuarius and Phyllurus species just three—the Southern Leaf-tailed Gecko S. swaini, the Broad-tailed Gecko P. platurus and the Rough Throated Leaf-tailed Gecko S. salebrosus are represented in moderate numbers in captivity. The Ringed Thin-tailed Gecko P. caudiannulatus, the Northern Leaf-tailed Gecko

Saltuarius salebrosus

page 210

D FISCHER

S. cornutus, the Moritz’s Leaf-tailed Gecko S. moritzi and the Wyberba Leaf-tailed Gecko S. wyberba are reasonably rare and the remaining species are virtually non-existent in private collections. The Wyberba Leaf-tailed Gecko S. wyberba and the Ringed Thin-tailed Gecko P. caudiannulatus are better established overseas than in Australia.

S MACDONALD

S MACDONALD

Phyllurus platurus

Saltuarius swaini

Saltuarius wyberba

page 211

G CALVERT

Saltuarius cornutus

HOUSING Leaf-tailed geckos are generally easy to maintain, relatively inactive and non-aggressive.

INDOOR ENCLOSURES Suitable enclosures include commercial glass terrariums, mesh enclosures, fish tanks and timber enclosures. These should measure a minimum of 4−6 SVL long x 4−6 SVL wide x 4−6 SVL high for housing a pair of larger species or a trio of smaller species. Suitable substrate is sphagnum moss, peat moss or potting mix. Species that inhabit rocky areas will also accept a substrate of bark. Most species require a moderate humidity level of 50−90%. Spraying the enclosure regularly with water or using moisture retaining substrates is recommended. These species seem to be constantly shedding their skins and shedding problems may be encountered if the environmental humidity is low. They are quite clean and will often defecate in just one part of the enclosure— usually the front. Provide large bark slabs or large, flat rock pieces positioned vertically depending on the natural origin of the species. Logs or rocks with a natural covering of lichen will provide good grip for specimens that rest vertically. These species are generally unable to climb glass, therefore firm branches placed vertically and horizontally are appreciated for climbing. Resting geckos will make use of a large, flat surface created by painting the back wall of the enclosure in textured paint or paint with sand embedded. They will also enjoy areas created by layers of vegetation. Leaf-tailed geckos are particularly heat sensitive. Heating is generally unnecessary for these geckos unless ambient temperatures regularly drop below 15oC. Overheating is much more of a problem and temperatures above 28oC should be avoided. The ideal temperature for an enclosure is 22oC−26oC. Phyllurus species appear to be more sensitive to temperatures than page 212

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Saltuarius species. A common warning sign of overheating is the loss of tails in established adults. Enclosures should be placed in cooler areas of a room or as low in the room as possible. Regular misting will help maintain lower temperatures. If necessary, small wattage coloured light bulbs, heat pads or heat cords can be used for heating and will not dry the enclosure. A thermostat set at 26oC–27oC will prevent overheating. Active cooling during winter is only considered necessary for breeding geckos. Juveniles do not need to be cooled over winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. The provision of UV-B light is not Components of a suitable enclosure essential for these species, although it may benefit juveniles prone to metabolic bone disease. If supplied, UV-B lights of 5% or more are ideal—considering most specimens originate from tropical areas. In addition to water provided by misting, a water bowl should be available at all times.

Summary A basic enclosure for leaf-tailed geckos should include the following— • A substrate of peat moss or sphagnum moss, kept moist to maintain environmental humidity. • Large, flat bark or rock slabs that are consistent with the species’ natural habitat, vertical or diagonal branches, layers of vegetation including artificial plants and a textured enclosure wall. • Heat cord, heat pads or heat lamps to provide temperatures of 22oC−26oC if ambient temperatures drop below 15oC. • A nestbox. • A water bowl.

OUTDOOR ENCLOSURES Some species are suited to outdoor housing in climates similar to their natural habitat—particularly the Southern Leaf-tailed Gecko S. swaini, the Broad-tailed Gecko P. platurus and the Northern Leaftailed Gecko S. cornutus. Well-decorated and planted suspended enclosures located in a shady position have been used successfully. The main consideration when using outdoor housing is overheating in summer—provide a water misting system to maintain a cool, humid environment during this period.

COMPATIBILITY Leaf-tailed geckos are moderately placid towards each other. They can be housed as pairs, trios and groups consisting of one male and multiple females. Multiple males within an enclosure do not physically fight as Oedura geckos do, however intimidation can occur and result in males not feeding and losing their tails. page 213

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Saltuarius cornutus

These species will become accustomed to their keeper quite easily, but do not enjoy being handled. They often vocalise and may attempt to bite when handled. Leaf-tailed geckos have successfully been maintained with Southern Angle-headed Dragons Hypsilurus spinipes, Eastern Water Skinks Eulamprus quoyii and Giant Cave Geckos Pseudothecadactylus lindneri.

FEEDING In the wild, leaf-tailed geckos are opportunistic feeders and will consume any large insects available. They feed by sitting and waiting for their prey to pass by and pouncing, but will sometimes pursue the food item a short distance. They can be observed in a typical feeding posture of a vertical, head down manner when foraging. They will often consume items as large as their head. In captivity, they will accept crickets, moths and cockroaches and feed in a similar manner as in the wild. Insect food item size should measure approximately 60% of an individual’s head size. Adults prefer large items—more than 50% of their head size—to small items if given the choice. Food items should be lightly dusted with a calcium and vitamin D3 supplement in at least two out of three feeds. Adults should be fed every 4−7 days in summer and every 10−14 days in winter. Although leaftailed geckos remain active and feed at much lower temperatures than other gecko species in winter, they do not need to be fed as regularly. Juveniles should be fed every 2−4 days throughout the year. Leaf-tailed geckos are not overly aggressive feeders but will become accustomed to feeding time quickly, positioning themselves close to the enclosure floor in anticipation of feeding when occupants in adjacent cages are being fed. page 214

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Saltuarius salebrosus at the entrance to its nest box

BREEDING

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Eggs are clearly visible through the abdominal skin in Saltuarius wyberba

In the wild, breeding occurs from late spring to early summer—generally from October to January. In captivity, the breeding season commences earlier—from mid-September to mid-January, possibly due to food supply. Individuals are not capable of reproduction until they reach at least three years of age— these species are very slow to mature. Pair separation is not essential for breeding success and pairs and groups, including one male and multiple females, may be maintained together throughout the year. Out of season Leaf-tailed gecko eggs generally have large amounts breeding is rare—females can rest in the non- of adherent substrate—Saltuarius swaini breeding period in the presence of males. Spermatozoa storage does occur in these species, therefore separation mid-season has little impact on cessation of breeding activity. Some females may produce fertile eggs in the absence of a male for at least seven months. Active cooling is not essential but can be achieved by doing nothing—the seasonal reduction in the ambient room temperature is adequate for stimulating breeding activity. Courtship has not been recorded. Mating is generally initiated in early spring. The first eggs can be expected once ambient temperatures rise above 22oC. A gravid female can be identified by a marked increase in girth. The eggs will be visible as distinct shapes through her abdominal wall. page 215

A typical clutch for most species in this group is two eggs. The eggs are oval-shaped and leathery-shelled. In captivity, 3−4 clutches are laid each year. The interval between clutches is usually 30−40 days. In captivity, nest facilities are easy to provide. All species will nest in a tall and deep plastic container approximately 2−3 SVL deep and 1−2 SVL in diameter. It should have an opening near or on top of the lid and be filled three-quarters with either moistened coir peat or sphagnum moss. Nesting is usually preceded by the digging of test holes 2−3 days before laying. The eggs are laid on the bottom of the container. When laying, the female usually stands vertically in the hole she has dug, often some distance from the bottom, and allows the eggs to roll a short distance to the bottom of the hole—she then backfills the hole using her hind limbs. The eggs are sticky when laid and can become thickly coated in nesting container substrate, much more so than any other gecko species.

INCUBATION AND HATCHLING DEVELOPMENT

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Once laid, eggs should be removed for artificial incubation. Incubation should be in a mixture of water and vermiculite at a ratio of 1:1 by weight or 1:10 by volume. Incubation is relatively simple and without problems in these species—provided a few basic rules are observed. Standard nonvented incubation containers are suitable. Incubation at regular incubation temperatures of 28oC−30oC results in poorer hatchability than eggs maintained at lower fluctuating temperatures. I incubate eggs at room temperature, which results in a daily fluctuation of 21oC−29oC. There should be no issues unless the high temperature peaks are sustained for more than a few hours. I am unsure why leaf-tailed geckos exhibit this apparent temperature sensitivity—other species that are heat sensitive as adults, such as thicktailed geckos, are incubated at higher and more stable temperatures without problems. Due to temperature fluctuations during incubation, it is impossible to ascertain the possibility of temperature dependent sex determination. Considerable egg expansion occurs during incubation with increases of up to 40% in width and 25% in length common. If non-vented incubation containers are used, egg sweating will precede hatching by 24 hours.

Partially emerged Saltuarius swaini hatchling

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BREEDING RECORDS FOR LEAF-TAILED GECKO SPECIES Clutch Size

Interclutch Interval (Days)

Egg size (mm) (Mean or Range) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

P. caudiannulatus

2

−

17.4−21.6 x 9−13.5

60−85 (23oC−27oC)

33.4−37.4 SVL

P. championae

2

−

17.7−18.3 x 8.9−9.0

−

−

P. platurus

2

30−31

18.6−25.5 x 9−15.8

66−72 (22oC−26oC) 85−98 (20oC−25oC)

30−41/ 60−64

S. cornutus

2

28−30

23.3−28 x 13.6−18

66−100 (24oC−27oC)

47−51.4/75

S. moritzi

2

−

21−22 x 11−12

−

−

S. salebrosus

2

32−40

S. swaini

2

30

22.4−26 x 13.2−14

72−106 (22oC−27OC) 40.7−48.9 SVL

S. wyberba

2

43−50

21−22.9 x 13.2−14

64−76 (24oC−27oC)

SPECIES

27.7−29.5 x 16.5−17.5 82−108 (22oC−26oC)

49/78

45/68

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small holding container furnished with a layer of moist peat moss on the container floor, a small hide—usually a piece of bamboo approximately 15cm long x 2cm in diameter— and a water bowl. Hatchlings should be maintained at an ambient temperature of 20oC−25oC. Food should be offered 24 hours after hatching. Initially, items should measure approximately 25−35% of the hatchling’s head size and be increased in size to 50−60% after two weeks. Suitable food items include crickets, cockroaches and slaters.

HYBRIDISATION AND COLOUR VARIANTS Hybridisation has not been recorded in these species. Every population within a single species is generally separated and isolated by significant habitat barriers, therefore it is important that individuals from specific localities are maintained in purity. Taxonomically, leaf-tailed geckos are constantly being separated and reallocated—it is likely many more locality specific forms will be considered as separate species. I am only aware of one colour mutation among leaf-tailed geckos—a line of Albino Southern Leaf-tailed Gecko P. platurus under development.

LONGEVITY Leaf-tailed geckos live moderately long lives, expected of a species that take so long to mature. The average life span is 10−12 years with a productive period of 6−8 years. Some exceptional specimens may live to 15 years of age.

ACKNOWLEDGEMENTS I would like to thank Rob Porter and Derek Dunlop, among others, for their assistance with this chapter. page 217

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Strophurus taenicauda taenicauda

SMALL ARBOREAL GECKOS The small arboreal gecko group comprises 18 species of gecko—17 Strophurus species and one Crenadactylus species including— Northern Spiny-tailed Gecko Strophurus ciliaris Jewelled Gecko Strophurus elderi Southern Spiny-tailed Gecko Strophurus intermedius Kristin’s Gecko Strophurus krisalys Soft Spiny-tailed Gecko Strophurus spinigerus Western Spiny-tailed Gecko Strophurus strophurus Golden-tailed Gecko Strophurus taenicauda Eastern Spiny-tailed Gecko Strophurus williamsi Clawless Gecko Crenadactylus ocellatus

PRONUNCIATION Following are the accepted pronunciations of the most common members of the small arboreal gecko species. Strophurus ciliaris Stroff-you-rus sil-ee-ah-rus Strophurus elderi Stroff-you-rus ell-der-ee Strophurus intermedius Stroff-you-rus in-ter-mead-ee-us Strophurus krisalys Stroff-you-rus chris-ah-lis Strophurus spinigerus Stroff-you-rus spee-ni-jer-us Strophurus taenicauda Stroff-you-rus teen-ee-cord-ah Strophurus williamsi Stroff-you-rus will-ee-am-see Crenadactylus ocellatus Cren-ah-dack-til-us os-ell-ah-tus page 218

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Strophurus ciliaris ciliaris

Strophurus intermedius

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Strophurus intermedius

Strophurus elderi

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Strophurus taenicauda albiocularis D BROWN

Strophurus strophurus G SCHMIDA

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Strophurus krisalys

Strophurus taenicauda triaureus

Strophurus williamsi, reticulated form

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Strophurus williamsi, spotted form

Strophurus rankini

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Strophurus taeniatus

Strophurus elderi

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M ANTHONY

Strophurus jeanae

DESCRIPTION ADULTS Small arboreal geckos are generally of small size with slender bodies and caudal tail glands. They range in size—the smallest species the Clawless Gecko C. ocellatus measures 30mm SVL and the largest species the Northern Spiny-tailed Gecko S. ciliaris measures 89mm SVL. The majority of species in this group measure 60–80mm SVL.   A typical specimen measuring an average length of 75mm SVL will weigh an average of 10−11 grams. Strophurus species are colloquially referred to as spiny-tailed geckos, striped geckos, goldentailed or jewelled geckos. They are mostly silver-grey in colour—within some species there are colour variations including red, white and chocolate brown. The eyelids and upper surface of their tail usually features variable rows of spines and the back is patterned with spots, blotches, zigzags or black or dark grey lines. Single individuals may display considerable variations in diurnal colour. In a single day, the Northern Spiny-tailed Gecko S. ciliaris may change from white to grey and then to brown depending on the ambient temperature, light, its mood and the colour of the background. The pattern on its back will also change. Striped geckos display multiple, full-length stripes that are yellow, brown or grey in colour. Golden-tailed geckos are heavily patterned in black, white and gold. Jewelled geckos are silver-grey in colouration with minute white spots. Selective breeding of specimens with extreme colour patterns, such as brighter colours or more extensive banding or stripes, can result in the production of populations of enhanced colour. The Clawless Gecko C. ocellatus is Australia’s smallest gecko. It is slender with a smooth tail and exhibits various patterns. Its overall morphology is similar to that of the striped Strophurus species. page 224

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Secretion from the tail glands of a Strophurus taenicauda taenicauda D BROWN

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Many Strophurus geckos are adorned with attractive colours and ornate spines. Strophurus ciliaris ciliaris

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Strophurus species can squirt or smear a secretion on an attacker. If grasped, stressed or otherwise unhappy, the tail glands (located between the scale rows) may discharge a sticky, amber fluid similar to the texture of golden syrup, which dries in a similar manner to sap upon exposure to the air. This secretion is quite pungent and will irritate the eyes and mucous membranes. The presence of regenerated tails in wild Hatchling Strophurus taenicauda triaureus specimens suggests this defence mechanism is not always effective. In captive bred specimens, it is generally only used by severely harassed or unwell individuals. I have found dead specimens coated in dried tail secretion after presumably discharging their tails in the throes of death. The spiny-tailed forms are all capable of tail squirting and may raise their tails and eject secretion to a distance of up to 60cm. Jewelled, golden-tailed and striped geckos usually smear or wipe the Hatchling Strophurus ciliaris ciliaris secretion onto their attacker. The Golden-tailed Gecko S. taenicauda can squirt the fluid to a distance of 50cm, although it rarely does.

JUVENILES Hatchlings are similar to the adult. Plain coloured species are generally less patterned and often paler than the adult, whereas heavily patterned species such as the Golden-tailed Gecko S. taenicauda are often darker than the adult. Hatchlings are generally 30−40% of adult SVL. Hatchling Strophurus williamsi page 225

Lateral view of paracloacal spurs in a male Strophurus ciliaris

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Ventral view of a female Strophurus ciliaris D BROWN

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Ventral view of a male Strophurus ciliaris

Lateral view of paracloacal spurs in a female Strophurus ciliaris

SEXING Small arboreal geckos are moderately easy to visually sex as adults, although there are not generally any discernable colour variation between sexes. Adult males display enlarged hemipenal bulges with a central depression and females display some smooth enlargement in this area but it is less developed and without a central depression. Some males may undergo an apparent seasonal reduction in hemipenal bulge size—the central depression and tubercles remain and are indicators of sex. Males possess paracloacal spurs that vary according to species. They generally consist of an arrangement of spines 2−3 times larger than the surrounding scales. Depending on the species, the spine cluster may include 2−7 enlarged scales positioned near the top of the hemipenal bulge near where it connects with the hind limb. These may be visible in females, but are rarely more than 50% larger than the adjacent body scales. Hemipenal transillumination can be used on hatchlings when they reach 30−50% of adult SVL and on adults—particularly males displaying a seasonal reduction in hemipenal size. Juveniles can usually be visually sexed when they reach 50−70% of adult SVL which can be attained at 6−12 months of age. page 226

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Crenadactylus ocellatus horni

SUBSPECIES

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The Strophurus group of geckos is taxonomically dynamic. It was separated from the Diplodactylus genus on the basis of being primarily arboreal and for possessing caudal tail glands. Although these glands are a suitable distinguishing character, variations within the Strophurus group suggests this is not the perfect separating feature to distinguish all members from the terrestrial species of Diplodactylus. For example, the Jewelled Gecko S. elderi possesses tail glands but physically resembles and behaves similarly to the terrestrial Diplodactylus species more than the other arboreal species with which it is aligned.

Strophurus ciliaris ciliaris

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Strophurus ciliaris aberrans

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There are several undescribed Strophurus forms and several species currently described under subspecies status that may warrant species separation. Only two Strophurus species have recognised subspecies—the Northern Spiny-tailed Gecko S. ciliaris and the South-west Spiny-tailed Gecko S. spinigerus. The Northern Spiny-tailed Gecko S. ciliaris is separated into S. c. ciliaris and S. c. aberrans. S. c. ciliaris is traditionally considered to have predominantly yellow or orange tail spines with flat granular scales between the spines. S. c. aberrans is traditionally considered to have predominantly black tail spines and slightly raised or sub-conical scales between the spines. Although I have not observed large numbers of S. c. ciliaris in the wild, I can confirm that both black and yellow spined S. c. aberrans can be found on the same stretch of road in some areas.

Strophurus ciliaris aberrans

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Strophurus spinigerus spinigerus

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I have seen two individuals of the same species that were collected from the wild only metres apart display opposite colouration on the tail spines—one had all yellow spines and the other all black spines. In my opinion this is a poor method for distinguishing geographical subspecies in this species. The shape of the scales between the spines is more reliable. The degree of DNA separation between these two subspecies, which is more than 11%, warrants their separation into full species. Strophurus ciliaris aberrans displaying conical The South-west Spiny-tailed Gecko S. spinigerus is scales between the scales separated into two subspecies—S. s. spinigerus and S. s. inornatus. S. s. spinigerus is found on the lower west coast of Western Australia and in adjacent hinterland. It displays a broad and dark grey dorsal stripe peppered with small white spots and a zigzag edge. The iris is maroon to brown with a yellow eye rim in southern populations and a white eye rim in northern populations. Strophurus ciliaris ciliaris displaying flat scales between the spines

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The three subspecies of the Strophurus taenicauda—Strophurus taenicauda triaureus (top), Strophurus taenicauda taenicauda (centre) and Strophurus taenicauda albiocularis (bottom)

S. s. inornatus is found in the south-east and interior of Western Australia. It lacks the dorsal stripe of S. s. spinigerus and has an orange-red eye rim. The Golden-tailed Gecko S. taenicauda has recently undergone a taxonomic review by myself and is now formally described as three subspecies, based on tail morphology, body patterning, scale patterning, eye colour,and DNA evidence. The Southern Golden-tailed Gecko, which is the nominate and commonly recognised form and is found in the south of the species range. It has a reticular pattern on the tail and body with each spot comprising 3−5 scales and interscale separating bands one scale wide. The eyes are a bright red-orange and the tail has a gold coloured stripe with undulating borders. This stripe varies in length from the nape to the neck in some individuals, or to just the dorsal surface of the tail in others. An aberrant form of the Southern Golden-tailed Gecko with a fine, peppered appearance is found in the Carnarvon Gorge and Injune area, Queensland. This form has interscale bands one scale thick and spots comprising 1−2 scales—it otherwise has similar morphology. The Northern Golden-tailed Gecko Strophurus taenicauda albiocularis is found in the northern part of the species range from Emerald to Blackwater and south to Glenhaughton, Queensland. It has white or yellowish eyes and is light grey-brown in colour with smaller black spots on the body than the nominate form. These spots comprise 3−5 scales with inter-scale separating bands 2−3 scales wide. Numerous black scales with central white spots are found adjacent to the single straight tail stripe. The tail stripe rarely continues past the hips, but may in some specimens. page 230

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Tail patterning of Strophurus taenicauda taenicauda

Tail patterning of Strophurus taenicauda triaureus

Tail patterning of Strophurus taenicauda albiocularis

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Eye colour of Strophurus taenicauda taenicauda

Eye colour of Strophurus taenicauda triaureus

Eye colour of Strophurus taenicauda albiocularis

Spotting resembling the markings on the border of the tail continues up the dorsal midline in a thin stripe to shoulder level. The Central Golden-tailed Gecko Strophurus taenicauda triaureus is found in the north and northeast from Mundubbera to Callide, Queensland. It has pale amber eyes and a plain, spotted body. The body scales are smaller than most forms and each spot comprises only 1−2 scales. The inter-scale separating bands are 2−4 scales wide. The circumference of the tail is ringed in black and white alternating bands, created not by alternating scale colours, but by a white vertical stripe present in each black scale. Three golden tail stripes—one dorsal stripe with straight borders and two lateral thin, undulating lateral stripes—extend to hip-level. The Southern Spiny-tailed Gecko S. intermedius displays sufficient variation to warrant at least subspecies differentiation between individuals from north-western New South Wales, South Australia and the central Northern Territory where they are not, at the time of publication, officially supposed to exist. Populations of the Southern Spiny-tailed Gecko S. intermedius in southern South Australia that superficially resemble Strophurus assimilis have been referred to as S. i. burrelli. The Jewelled Gecko S. elderi is officially recognised as a single species. However, there is considerable variation in the morphology of numerous forms of Jewelled Gecko S. elderi. Specimens from the southern Northern Territory and South Australia have strong black rimmed, white dorsal ocelli that extend onto the tail but are absent from the head and lightly spotted limbs. Specimens from central Western Australia are darker in colouration with small white spots restricted to the dorsal body and mostly absent from the limbs. Specimens from western Queensland and New South Wales are heavily spotted on the head, body, limbs and tail. The Clawless Gecko C. ocellatus is separated into four subspecies—C. o. ocellatus found in south-western Western Australia, C. o. horni from Western Australia and the Northern Territory, C. o. rostralis found in the southern Kimberley region of Western Australia and in the Northern Territory and C. o. naso from the northern Kimberley region. Each subspecies varies in colouration, rostral scalation and preanal pore distribution. The morphological differences may warrant species separation. Several other undescribed forms also exist. page 231

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Typical habitat of Strophurus taenicauda and Strophurus williamsi, Brigalow scrub, Glenmorgan, Queensland

IN THE WILD DISTRIBUTION AND HABITAT Small arboreal geckos are distributed throughout mainland Australia, except in south-eastern Victoria, along the eastern coastline and in Tasmania. In the north of the range they occupy more humid areas and in the south of the range they are found in arid and semi-arid areas. Habitat includes woodland, grasslands and open country. Some Strophurus species inhabit hummock grasses and Spinifex exclusively. The Clawless Gecko C. ocellatus is opportunistic and striped forms will often inhabit Spinifex, while other subspecies can be found in rock crevices, surface debris, underneath pieces of bark or in tussock type grasses. Typical habitat of the Strophurus ciliaris aberrans, Undoolya Station, Alice Springs, Northern Territory

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Typical habitat of Strophurus elderi, Wiluna, Western Australia

Typical habitat of Strophurus spinigerus, Kalbarri, Western Australia

Behaviour varies, but most small arboreal geckos generally forage in the upper branches of foliage such as grasses, shrubs or trees at night. They also forage on the ground while moving between trees. Their characteristic posture when resting is with their head pointed downwards and they sleep by day on the stems and branches of grasses and shrubs. Most Strophurus species also shelter beneath bark or in tree hollows.

IN CAPTIVITY STATUS

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Strophurus geckos are relatively popular in captivity due to their highly visible habits and the attractive colouration and structural features of some species. The Northern Spiny-tailed Gecko S. ciliaris and the Golden-tailed Gecko S. taenicauda account for approximately 90% of Strophurus in captivity, however other species are slowly increasing in numbers. Species originating from Western Australia are held in the lowest numbers. Legislation in some Australian states may prohibit or restrict the keeping of some Strophurus species—for example, some states have either prohibited or restricted keeping of the Goldentailed Gecko S. taenicauda, whereas others consider it a beginner’s species and allow it on the most basic licence.

Strophurus ciliaris ciliaris

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HOUSING These geckos are easy to maintain and primarily arboreal, although they also move around the floor at night while feeding. An enclosure should ideally cater for both behaviours and also take into account their superb climbing ability.

INDOOR ENCLOSURES Suitable enclosures include plastic terrariums, fish tanks, commercial terrariums or plastic tubs. These should measure a minimum of 5−7 SVL long x 5−7 SVL wide x 6−10 SVL high for housing a pair or trio. Enclosures do not need to be particularly large as these species use enclosure space well—excessively large enclosures will make it more difficult for the inhabitants to catch insects before they have rid themselves of calcium or vitamin powder coating. Close fitting lids are essential, as these geckos can climb glass and will often seek refuge at the top edge of the wall where it meets the enclosure lid. Components of a suitable enclosure Suitable substrate is sand or loose clean leaf litter—however, substrate isn’t overly important. Provide upright branches of a width similar to the occupant’s tail width—dry branches can be permanently fixed in the enclosure or fresh branches of Leptospermum, Casuarina, Melalaeuca or Callitris can be replaced every few weeks. They should be placed horizontally, vertically and at oblique angles. Provide Spinifex grass or other firm tussocky grass for species including the Jewelled Gecko S. elderi, the striped Strophurus species and the Clawless Gecko C. ocellatus. Small arboreal geckos are not shy—or they at least rely on the misconception they are always well camouflaged. Therefore, enclosures can be designed to allow occupants to be visible most of the time—provided dark hide areas are still included. Some small arboreal geckos bask, however active heating is not always essential. Temperatures of 26oC−30oC are recommended for 10−14 hours per day in summer and temperatures of 15oC−20oC in winter. A basking lamp can be used, however it will not cater for nocturnal behaviour. Alternatively, heat can be provided using heat cord or heat tape placed vertically along a wall. Active cooling during winter is only considered necessary for breeding geckos. Juveniles do not need to be cooled over winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. The provision of UV-B light is not essential for these species, although it may benefit juveniles and breeding females. Some breeders report lower hatchling mortality when breeding adults are supplied with UV-B. UV-B lamps of 5% UV-B are ideal. It may not be required if adequate calcium and vitamin D3 is provided through the diet. A bowl of water should be supplied at all times. Some specimens will drink water droplets off vegetation if lightly misted. page 234

Summary A basic enclosure for small arboreal geckos should include the following— • A substrate of sand or light leaf litter on the floor. • Thin branches the same width as the occupant’s tail, positioned vertically, diagonally and horizontally throughout the enclosure. Alternatively, upright grass clumps such as Spinifex can be provided. • A heat pad, heat cord or small heat lamp providing temperatures of 26oC−30oC in summer and temperatures of 15oC−20oC in winter. • A moist hide site or nest box. • A water bowl.

OUTDOOR ENCLOSURES Small arboreal geckos are rarely maintained in outdoor enclosures although, of all the gecko species, they are most suitable for this style of housing. Their open, exposed sleeping habits mean they are visible at all times—unlike most other species—which makes them aesthetically suitable for an outdoor mesh or suspended wire enclosure. A small potted shrub can be provided as a natural perching site. In fact, in situ hatching of eggs within potting mix has been recorded. Most species will do well in outdoor enclosures in areas similar to their natural origin. Queensland endemic species can cope with higher humidity when kept along the eastern coastline. Specimens can be taken inside for the winter or during inclement weather.

COMPATIBILITY Small aboreal geckos are generally placid. They display virtually no sign of aggression towards conspecifics and may be maintained as pairs, trios and groups consisting of multiple males and up to six females. Although they do not physically interact with other individuals, only one male per enclosure is recommended. If two males are housed together, one will often feed less and lose weight—possibly due to dominance issues. This behaviour does not appear to occur when females are absent.

FEEDING In the wild, small arboreal geckos feed on small arthropods including cockroaches, crickets, grasshoppers, beetles, moths and spiders. Species including the Jewelled Gecko S. elderi and the Clawless Gecko C. ocellatus feed heavily on termites but will also consume small arthropods. In captivity, all species will accept crickets, cockroaches, moths, flies and waxmoth larvae. Small hatchlings may be offered small crickets, cockroaches and termites. The Jewelled Gecko S. elderi and the Clawless Gecko C. ocellatus will consume termites but they are not a necessary dietary component. Food item size should measure approximately 60% of an individual’s head size, although some individuals will consume much larger items. Large items are not recommended for juveniles. A four-month-old Northern Spiny-tailed Gecko S. ciliaris specimen I kept developed a stomach impaction after consuming a large cricket—the gecko was unable to digest the highly keratinous head shields of the cricket. I have also observed numerous juveniles suffer spinal paralysis presumably caused by the upward pressure of large food items in the stomach compressing the overlying spine. These individuals are likely to have been marginally deficient in calcium and, therefore, had weak vertebral columns. page 235

Food items should be lightly dusted with a suitable calcium and vitamin D3 supplement in at least two out of three feeds. Dusting is particularly important if UV-B light is not supplied. Adults should be fed every 4−7 days in summer and every 7−10 days in winter, although they may not accept food for short periods during this time. Juveniles should be fed every 2−4 days throughout the year.

BREEDING

D WONG

In the wild and in captivity, breeding occurs from September to February. This can be extended from August to April in response to good environmental conditions and rainfall. Breeders in northern Australia have noted some species breed throughout the year if conditions are suitable—particularly the Northern Spiny-tailed Gecko S. ciliaris. Individuals are capable of reproduction when they reach 80% of adult SVL, which may occur at 12−18 months of age, although two years of age is more common. Pair separation is not essential for breeding success and pairs and groups may be maintained together throughout the year. Spermatozoa storage does occur and separated females may still produce fertile clutches. If cooling is practiced, it can be achieved by gradually reducing the number of heating hours and temperatures to the desired winter minimum. Courtship is similar between species and involves the male licking the female and then grasping her shoulders and neck. A male Golden-tailed Gecko S. taenicauda has been observed twisting the tip of his tail around the female’s tail and the branch she was resting on. Mating is generally initiated within 4−6 weeks of temperatures rising above 25oC if cooling has been practiced. The first eggs can be expected within a month of first mating behaviour. A gravid female can be identified by a marked increase in girth, although this is less noticeable in some species due to their longer bodies. The eggs will be visible as distinct shapes through the female’s abdomen in only some individuals—abdomen skin among small arboreal geckos is less translucent than in other species. A typical clutch is two eggs, although occasionally only one will be laid. The eggs are ovalshaped and soft-shelled. They are moist when first laid, which can cause the substrate to stick to them. It is not necessary to attempt to clean the eggs before transfer to an incubation container.

Mating Strophurus ciliaris aberrans

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D BROWN

The interval between clutches varies—the Northern Spiny-tailed Gecko S. ciliaris may produce multiple clutches every 3−6 weeks, with 5−7 clutches produced in southern states and up to 10 clutches in northern regions. Excessive breeding will shorten the reproductive life span of a female, therefore they should be rested after producing 3−4 clutches. Some incidences of egg binding have been noted in prolific females, but this is less common if UV light is supplied to the breeding females. In the wild, females lay their eggs in soil cracks, in the walls of large disused animal burrows and presumably in the soft soil at the base of trees and under debris. In captivity, nest facilities are easy to provide. These species will accept any type of container filled 5−10cm deep with a semi-moist nesting medium such as sphagnum moss or a mix of sand and peat. The eggs are usually laid on the bottom of the container. If a container is not supplied, females will lay in an area of moist substrate. Females will generally dig several test A gravid Strophurus williamsi holes several days before laying.

INCUBATION AND HATCHLING DEVELOPMENT Once laid, eggs should be removed for artificial incubation. Incubation should be in a mixture of water and vermiculite (or perlite) at a ratio of 1:1 ratio by weight or 1:10 by volume. Incubation is relatively simple and without problems in these species, although I have encountered hatching problems in hot, humid conditions. Eggs should be incubated at temperatures of 27oC−30oC. While these temperatures provide ideal conditions, they may result in the production of a disproportionate number of males, possibly due to the existence of temperature dependent sex determination (TSD) in these species. Anecdotally, evidence suggests that eggs incubated at 23oC−24oC predominantly produce female hatchlings. Typical temperatures of 27oC−30oC produce both sexes, however males seem to predominate. The outcomes of incubation at temperatures above 30oC are not well established—however, it could be assumed this would bias towards female offspring if the TSD is of the expected Type Three. Although incubation at room temperature can be successful, it increases the length of the incubation period considerably and may leave the eggs more susceptible to fungal attack. Considerable egg expansion occurs during incubation with increases of up to 50% in width and 25−30% in length being typical. Eggs may also develop an almost transparent shell due to ‘windows’ in the period prior to hatching. If non-vented incubation containers are used, egg sweating will precede hatching by 24−36 hours. There is likely to be a problem if sweating extends beyond this period. Eggs that have sweated for up to 3−5 days will invariably fail and, when opened, will contain a fully developed juvenile bloated with fluid (anasarcia). I am unsure if this is due to egg factors, such as an inability to lose sufficient fluid due to high humidity, fluid loss mechanisms being damaged by high temperatures or shell membrane structures being damaged; or hatchling factors, such as weakness due to neonatal metabolic bone disease secondary to poor parental calcium supply. page 237

This type of egg failure is more of an issue in northern states. I have not had the ability to move an egg to a drier container at the appropriate moment to see if this will save a hatchling. Regular venting later in the incubation period may reduce mortalities at this stage. Some breeders record fewer mortalities when parents are exposed to UV-B light, supporting a metabolic bone disease theory to some degree.

BREEDING RECORDS FOR SMALL ARBOREAL GECKO SPECIES Clutch Size

Interclutch Interval (Days)

Egg size (mm) (Mean or Range) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

S. ciliaris aberrans

2

21−42

14−16.5 x 8−9

50−80

52 TL

S. ciliaris ciliaris

2

−

14−16 x 8−9

55−66 (28oC−29oC)

29−31.5/ 46−53

S. krisalys

2

−

−

42−59 (28oC)

25/46

S. taenicauda

2

21−42

14.6−19.9 x 7.1−9.6

48−77 (27oC−29oC)

27−32/44

S. jeaneae

2

−

6−7 x 3

−

−

S. intermedius

2

21−35

14.5 x 9

41−59

28/48

S. williamsi

2

25−42

13.9−15 x 8.2−9.4

43−48

25−27/41−46

S. assimilis

2

−

13−14 x 8

−

−

S. elderi

2

18−25

12.5 x 7.5

41−45 (28oC−30oC)

23−24/36−37

S. strophurus

2

−

12 x 7

−

26/45

S. spinigerus

2

−

13.8−16 x 7.4−9.6

52−57 (28oC−31oC)

43−58 TL

C. ocellatus

2

−

5x3

39−40 (30oC)

11/22

SPECIES

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small enclosure furnished with floor-level hides and climbing branches—these will be used more frequently as the hatchlings mature. Substrate is unnecessary. Hatchling containers should not have a volume of more than 250ml or the hatchling may have difficulty feeding. Small takeaway containers are ideal for the first six months. A heat cord or mat should be supplied under part of the enclosure to provide a basking temperature of 26oC−28oC. Food should be offered 24 hours after hatching. Initially, items should measure approximately 25−35% of the hatchling’s head size and be increased in size to 50−60% after two weeks. Suitable food items include small crickets, cockroaches and slaters. The provision of UV-B light may reduce the risk of metabolic bone disease and rickets. page 238

HYBRIDISATION AND COLOUR VARIANTS

D BROWN

There are few records of hybridisation occurring between Strophurus species or subspecies. A hybrid between the Golden-tailed Gecko S. taenicauda and the Eastern Spiny-tailed Gecko S. williamsi was recorded in Europe more than 15 years ago and an identical specimen was found in the wild near St George, Queensland, in 2003. Both captive and wild occurring individuals appear smaller and slightly more spotted than a normal Golden-tailed Gecko S. taenicauda but lack both the golden tail stripe of Golden-tailed Gecko S. taenicauda and the tail spines of the Eastern Spiny- Spotted (left) and reticulated pattern of Strophurus williamsi tailed Gecko S. williamsi. There are numerous colour variants in wild and captive populations, however the naming of these variants is very confusing. Within wild populations there is considerable geographic variation in colour. Some of these variants are often named according to a specific location from which they originated and these names are often applied incorrectly. For example, large red phase S. c. ciliaris are often referred to as the ‘Katherine’ form (regardless of their geographical origin) due to their superficial similarity to a spectacular specimen from Katherine, Northern Territory, referred to in a popular text. I prefer to call a spade a spade—if the location is known it should be specified, but when unknown, the lizard should be referred to by its colour form (for example, Red Phase) or broad known locality (Top End, Northern Territory form). The Eastern Spiny-tailed Gecko S. williamsi has two well recognised colour variations that can be selectively bred—a spotted form and a reticulated form. The reticulated form has black spots arranged in a loose chicken wire or zigzag pattern with dark dorsal scalation. These forms also occur together in wild populations and both spotted and reticulated forms can be produced in a single clutch of eggs even if both parents are of the same form—suggesting that one colour morph is recessive in its mode of inheritance. As reticulated forms are less common in the wild and in captivity, it can be presumed that the reticulated morph is the less common autosomal recessive form.

LONGEVITY Small arboreal geckos live moderately long lives. The average life span is 4–8 years with a productive period of 5–6 seasons. Some exceptional specimens live to 10 years of age and still produce viable offspring.

ACKNOWLEDGEMENTS I would like to thank  Rob Porter, Sav Timpano, John McGrath, Richard Zychski and Friedrich Wilhelm Henkel, among others, for their assistance with this chapter. page 239

G SCHMIDA

Cyrtodactylus tuberculatus

RING-TAILED GECKOS

The Ring-tailed Gecko group comprises six species as follows— Pascoe River Ring-tailed Gecko Cyrtodactylus adorus Hoskin’s Ring-tailed Gecko Cyrtodactylus hoskini Kimberley Ring-tailed Gecko Cyrtodactylus kimberleyensis Inland Ring-tailed Gecko Cyrtodactylus mcdonaldi McIlwraith Ring-tailed Gecko Cyrtodactylus pronarus Coastal Ring-tailed Gecko Cyrtodactylus tuberculatus

PRONUNCIATION Following are the accepted pronunciations of the Ring-tailed Gecko species. Sir-toe-dack-till-us ah-door-us Cyrtodactylus adorus Cyrtodactylus hoskini Sir-toe-dack-till-us hos-kin-ee Cyrtodactylus kimberleyensis Sir-toe-dack-till-us kim-burr-lee-en-sis Cyrtodactylus mcdonaldi Sir-toe-dack-till-us mac-donald-ee Cyrtodactylus pronarus Sir-toe-dack-till-us pro-nah-rus Cyrtodactylus tuberculatus Sir-toe-dack-till-us two-burr-que-lah-tus

DESCRIPTION ADULTS The Ring-tailed Gecko group is Australia’s largest gecko species based on total length. They are active and voracious. Although their body is slender, they are solid and strong with a long, narrow tail that is carried semi-erect. page 240

S EIPPER N STOCK

Cyrtodactylus mcdonaldi

Cyrtodactylus tuberculatus D LYNCH

They range in size—the smallest species the Kimberley Ring-tailed Gecko C. kimberleyensis measures 45 mm SVL and the largest species the Coastal Ringtailed Gecko C. tuberculatus measures 140mm SVL. The majority of species in this group measure 110–120mm SVL with a total length of more than 300mm. A typical specimen measuring an average length of 100mm SVL will weigh an average of 19–22 grams. Their basic patterning consists of variable numbers of transverse bands of brown and white across the body and tail although C. kimberleyensis is unbanded. Cyrtodactylus tuberculatus page 241

S EIPPER R CLARKE

Hatchling Cyrtodactylus mcdonaldi

JUVENILES Hatchlings are a brighter version of the adult with patterning of greater contrast. The bands at the front of the body alternate between brown and tan, becoming black and white over the hind limbs and tail—these bands usually finish in a white tail tip. Their lips display small, vertical white marks. Coastal Ring-tailed Gecko C. tuberculatus hatchlings have yellow eyelids, while Inland Ring-tailed Gecko C. mcdonaldi hatchlings have grey or white eyelids. They are generally 25-30% of average adult size and achieve adult proportions at 12–18 months of age.

Hatchling Cyrtodactylus tuberculatus

SEXING

Ring-tailed Geckos are moderately easy to visually sex as adults. Adult males display significant hemipenal bulges. Females display some enlargement in this area but it is less developed and without a central depression. page 242

D BROWN D BROWN

D BROWN

Ventral view of a female Cyrtodactylus tuberculatus

D BROWN

Ventral view of a male Cyrtodactylus tuberculatus— note the preanal and femoral pores

Lateral view of paracloacal spurs in a male Cyrtodactylus mcdonaldi

Lateral view of paracloacal spurs in a female Cyrtodactylus mcdonaldi

Preanal and femoral pores are present in males, which possess a variable continuous row of 30–50 lightly pigmented pores. They are usually absent in females and, if present, are not swollen and tan in colouration as in males. Hemipenal transillumination can be used on adults and hatchlings once they reach 40% of adult SVL. Juveniles can be reliably visually sexed when they have reached 60–80% of adult SVL— attainable at 8–12 months of age with adequate nutrition. The development of preanal pores may be visible in some specimens when they reach 50% of adult SVL. There is some evidence to suggest that adults display nocturnal colour dimorphism, with males generally appearing paler and with greater contrasting than females. Authors working with this species overseas suggest this dimorphism may also exist in juveniles and may be used as an aid when sexing them—although the authors’ information may have been based on Cyrtodactylus irianjayensis. I have not tested this as a reliable means of sexing. page 243

D BROWN

SUBSPECIES

D BROWN

Taxonomically, the C. louisiadensis complex—of which the Australian Ringtailed Geckos were once a component— has been misidentified, reclassified and renamed numerous times. Generally, the C. louisiadensis complex has been characterised by specimens measuring more than 110mm SVL with banded dorsal patterning and in which males possess both preanal and femoral pores. The original type species description of C. louisiadensis was based on an individual from Sudest (Tagula) Island off the southern Body comparison of the Cyrtodactylus tuberculatus (left) coast of New Guinea—not an Australian and Cyrtodactylus mcdonaldi specimen. The naming of the key Australian species as C. tuberculatus is based on Lucas and Frost (1900) in which the Australian species, from the type locality Endeavour River, Queensland, was first described, mislabelled as Hoplodactylus tuberculatus and then subsequently overlooked. The Australian Cyrtodactylus population has recently (Shea et al 2011 and Bauer and Doughty 2012) been reviewed and the Australian mainland population now comprises five mainland species—two Head comparison of Cyrtodactylus tuberculatus (left) from the former range of C. tuberculatus and Cyrtodactylus mcdonaldi and three from the Cape York area of Queensland—and one species from East Montalivet Island, Western Australia. There is additional taxonomic confusion, as most references to C. louisiadensis maintained in captivity overseas refer to C. irianjayensis, which originates from New Guinea and the Solomon Islands. Morphologically, these two species are obviously different—C. irianjayensis has ragged edges to its body stripes, whereas C. louisiadensis has smooth-edged stripes. The two forms commonly kept in captivity were previously informally known as the ‘coastal’ morph of C. louisiadensis—now the Coastal Ring-tailed Gecko C. tuberculatus—and the ‘inland’ morph of C. louisiadensis, now the Inland Ring-tailed Gecko C. mcdonaldi. The Inland Ring-tailed Gecko C. mcdonaldi is found in the drier southern and western parts of the range and is the most common form. It has 6–7 bands on its body and 10–14 bands on its tail—the bands are solidly coloured or, if a darker boundary is present, only located on the caudal edge of the band. The body also features dirty brownish inter-band areas and a solidly coloured cap. The Coastal Ring-tailed Gecko C. tuberculatus is found in the northern and eastern parts of the range, and is morphologically similar to the Inland Ring-tailed Gecko C. mcdonaldi—except it has paler brown banding with darker boundaries and cleaner white interspaces, variable mottled limbs and a pale yellow upper eyelid. The cap is usually a paler tan with dark flecking. page 244

D FISCHER

Habitat of Cytrodactylus macdonaldi, Chillagoe, Queensland

IN THE WILD DISTRIBUTION AND HABITAT

M ANTHONY

Cytrodactylus is a large genus distributed across a wide area from the western Pacific Ocean to southern Europe. There are currently six Australian species, although Cyrtodactylus sadleiri from Christmas Island is technically a seventh Australian species as it occurs in an Australian territory. Ring-tailed Geckos are found in north-eastern Queensland from Chillagoe to Cape York and offshore from the Kimberely region, Western Australia. Habitats vary from dry inland granite outcrops and coastal rainforest to the giant black boulders of Black Mountain, near Cooktown, Queensland. They may also be found around farms and in urban areas adjacent to their natural habitat. Behaviour is primarily nocturnal, although I have observed specimens moving around rock crevices in the late afternoon. They forage on the ground among foliage and vines, on tree trunks and logs, and among rock fissures and non-vertical boulders. Habitat of Cyrtodactylus tuberculatus, Black Mountain, Queensland

page 245

M ANTHONY

Cyrtodactylus mcdonaldi

IN CAPTIVITY STATUS The Coastal Ring-tailed Gecko C. tuberculatus and Inland Ring-tailed Gecko C. mcdonaldi are held in small but stable numbers in captivity in Australia. However, licensing schedules in some states restrict or prohibit the keeping of them. Despite this, demand is increasing as the popularity of these geckos increase. The Cape York forms—C. adorus, C. hoskini and C. Pronarus—may currently exist in captivity but would have been maintained as C. tuberculatus, as all northern forms were previously included within this name.

HOUSING Ring-tailed Geckos are equally at home in terrestrial or arboreal environments, therefore any type of enclosure selected should be able to cater for these species. page 246

INDOOR ENCLOSURES Suitable enclosures include commercial glass terrariums, timber enclosures and commercial moulded plastic enclosures. Ring-tailed Geckos struggle on smooth surfaces, such as glass, due to the lack of adhesive lamellae on their toes. However, they do have sharp claws and can climb any other surfaces, including silicon remnants in the corners of fish tanks. Juveniles can easily climb the walls of plastic containers. Enclosures should measure a minimum of 4–6 SVL long x 3–4 SVL wide x 3–5 SVL high for pairs or trios. These geckos are excellent jumpers and can jump distances of 3–4 SVL vertically and horizontally. Suitable substrate includes leaf litter, sand or a mixture of sand and coir peat. An area of deeper sand under a hide is useful for breeding purposes. Provide ground level hides such as large upturned saucers, large pieces of bark, sections of hollow logs and bamboo and climbing structures such as vines, branches and rough textured walls. Despite their natural north-eastern Australian habitat and range, these species will not tolerate high temperatures in captivity. They are generally sensitive to temperatures above 30oC and I have encountered fatalities in these species at 34oC. In the wild, I assume they avoid temperature extremes by retreating into deep cavities in rocks and logs or sheltering in deep rainforest. Low temperatures are also dangerous and will result in specimens becoming sluggish and refusing to feed. During winter, enclosure temperatures should be maintained at 20oC–25oC. Temperatures of 27oC–30oC are recommended for 10–14 hours per day during summer. A small wattage light globe, heat tape or a UV-B fluorescent light can be used for heating. Active cooling during winter is only considered necessary for breeding geckos. Juveniles do not need to be cooled over winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. These species should have access to UV-B light—essential for breeding females. UV-B lamps of 5% UV-B are recommended. UV-B lighting provided for 8–10 hours per day during the breeding season can help prevent hypocalcaemia in multi-clutching females, which results in broken limbs, rubbery bones, seizures and egg binding. Dietary calcium alone appears insufficient to provide prolific egg laying females with sufficient calcium for the production of multiple clutches of hard-shelled eggs. If only one or two clutches of eggs are laid, females cope well and show no evidence of ill health. It is uncertain whether UV-B provision impacts on the development of juveniles or not—I have raised them successfully with and without UV-B. The provision of ventilation is essential in areas with high temperatures and in enclosures such as large plastic containers, fully enclosed glass terrariums or those with Perspex® fronts. The use of flywire or 8mm mesh on one wall or on the roof of the enclosure may assist with ventilation. Overseas literature often insists that all Australian Ring-tailed Geckos must be housed in high humidity environments—however, most of this advice refers to C. irianjayensis, a different species with a different habit requirement. Among the Coastal Ring-tailed Geckos C. tuberculatus and Inland Ring-tailed Geckos C. mcdonaldi in my collection, I have found they do not require high humidity. In fact, most actively seek out dry hide sites and spend little time in moist hides when they were provided. Cyrtodactylus species from Cape York, Queensland, may require higher humidity reflecting their more tropical origins. Overseas literature has also recorded the difficulties some herpetologists experience with dehydration or skin shedding in their specimens. Aside from species differences, the preferred habitat of the Coastal Ring-tailed Gecko C. tuberculatus and the Inland Ring-tailed Gecko C. mcdonaldi are different to C. irianjayensis. page 247

D BROWN

Most captive Australian specimens are Inland Ring-tailed Geckos C. mcdonaldi originating from the drier part of the range, which is dominated by large sandstone escarpments Even the Coastal Ring-tailed Gecko C. tuberculatus is found in areas of large granite boulders within rainforest areas. Water should be provided in a bowl at all times. Occasional misting may be carried out but should not wet the enclosure excessively.

Summary A basic enclosure for Ring-tailed Geckos should include the following— • A substrate of sand and coir peat kept Components of a suitable enclosure mostly dry, along with a deeper area to act as a hide. • Ground-level hides and numerous vertical climbing branches. • An appropriate heat lamp or heat tape providing a temperature of 27oC–30oC in summer and 20oC–25oC in winter. • A water bowl.

OUTDOOR ENCLOSURES Ring-tailed Geckos are suited to outdoor housing in areas where winter temperatures do not fall below 10oC at night. In other areas, they may be housed outdoors in summer or throughout the year, provided supplementary heating is provided. Suitable enclosures include suspended-style aviaries. These may be furnished with multiple overlapping bark slabs or rock exfoliations. A wire mesh or mock rock background allows for maximum use of the available space.

COMPATIBILITY Ring-tailed Geckos are generally placid towards each other. They can be housed in pairs, trios or groups of one male and up to five females. Multiple males will intimidate each other and should not be maintained together. Within their enclosures, these geckos will often be found congregating in communal hide sites, although they usually forage individually. I have successfully maintained the Coastal Ringtailed Gecko C. tuberculatus and the Inland Ring-tailed Gecko C. mcdonaldi with leaf-tailed gecko species Saltuarius and Phyllurus.

FEEDING In the wild, these species feed on large insects, small frogs and other geckos. They are aggressive feeders, often launching 20cm or more through the air to catch food items climbing up walls or attempting to flee. In captivity, they will accept any large insects including crickets, locusts, cockroaches and moths as well as pinkie mice. page 248

Food item size should measure up to 80% of an individual’s head size for adults and up to 60% of an individual’s head size for juveniles. Food items should be dusted with a suitable calcium supplement in at least two out of three feeds. In addition, a bowl of calcium carbonate powder may be supplied for breeding females. Intrigued by how these geckos access calcium in the wild in order to produce hard-shelled eggs, I uncovered a possible answer in literature regarding Uroplatus geckos, which consume small arboreal snails. To test these as a potential food source, I offered my Coastal Ring-tailed Geckos C. tuberculatus small aquatic snails from my fish tanks—these snails were approximately 20% of the geckos’ head size and were greedily consumed. Interestingly, they were swallowed whole and not chewed like a normal food item. They can be easily provided by placing them in the geckos’ water bowl, which they are reluctant to leave and where they will congregate around the edges in easy reach of the geckos. Adults should be fed every 3–7 days during summer and every 7–14 days during winter, although some adults will stop feeding during this period. Juveniles should be fed every 2–4 days throughout the year

BREEDING

D BROWN

In the wild, breeding is opportunistic and occurs from September to March, however herpetologists in northern Queensland indicate gravid females are not unusual from April to August. In captivity, breeding occurs from October to April, although less frequent clutches are recorded throughout the rest of the year. Individuals are capable of reproduction when they reach 70–80% of adult SVL which may occur at 12–18 months of age. Pair separation is not essential for breeding success and pairs and groups may be maintained together throughout the year. I do not separate my stock because of the possibility of out of season clutches being laid. However, heavily producing females may be given some rest. Reintroducing females to males after separation rarely poses a problem—apart from some initial over-amorous intentions. Cooling is not necessary and I do not actively practice it as my geckos are exposed to naturally cooler ambient temperatures within their enclosures. If cooling is practiced, it can be achieved by gradually reducing the number of heating hours and temperatures to the desired winter minimum. Courtship involves the male licking and biting the female’s shoulder and neck. I have not observed mating—it presumably takes place within the hides provided. As I have not observed mating, the period from mating to egg laying is difficult to determine. The first eggs laid by females that have been separated generally appear 5–7 weeks after reintroduction.

Eggs are clearly visible through the abdominal skin in this Cyrtodactylus tuberculatus

page 249

D BROWN

This Cyrtodactylus tuberculatus female has just dug out a nest site for laying—note the hide cover has been removed D BROWN

A gravid female can be identified by a marked increase in girth. The eggs will be visible as distinct shapes through her abdominal wall. A typical clutch is two eggs, although occasionally only one egg is laid. The eggs are round in shape and hard-shelled. These species, as well as Heteronotia, Christinus, Nactus, Lepidodactylus, Hemidactylus and Gehyra species, are unique in laying these types of eggs— it places them in the subfamily Gekkonidae, whereas the majority of Australian geckos belong to the subfamily Diplodactylinidae. Eggs are sticky when first laid and substrate commonly The eggs are partially soft for a short adheres to them period, and sticky when first laid, which may cause substrate to stick to them and can result in dents on the bottom. Substrate should not be removed, as a plug of shell may come with it. In captivity, females may produce up to six clutches per year. The interval between clutches is usually 46–63 days, although intervals of 150 days have been recorded. If the calcium required for laying exceeds a female’s calcium supply or metabolic processing, two problems can arise—thin-shelled eggs or calcium deficiency. Eggs may be so thin they collapse under the weight of the female when she is backfilling her nest site. If the calcium supply is not corrected, more serious problems may arise and the female may begin to develop signs of calcium deficiency such as seizures, paralysis, jaw fractures and multiple fractured limbs. Oral calcium liquid should be administered directly into the female’s mouth hourly for 3–6 hours and the individual placed under appropriate UV-B lighting. If the female is yet to lay her eggs, calcium supplementation must be provided at least twice a day until the eggs are laid. Up to 70% of these individuals may die. In my experience, 70% of lizards that page 250

D BROWN

survive hypocalcaemic episodes will be re-affected during the next clutch. Ring-tailed Gecko females use a variety of nesting and egg laying sites. Unlike most other species of gecko, they do not require semi-moist nest containers—they will usually ignore them and then lay in less appropriate sites if other sites are not made available. If a female does lay in a moist container, her eggs will often become mouldy. I encourage mine to lay their eggs in a mound of dry sand beneath a hide site or in a container of dry sand and dry, crumbled coir peat at a ratio of 50:50. is not uncommon for the substrate to leave If alternative laying sites are not provided, some It depressions in the surface of the egg females will lay their eggs in a shallow scrape in a corner beneath leaf litter or sand—this will usually result in the eggs sticking to the enclosure floor or wall, where they will need to be left to hatch in situ. A takeaway container can be placed over them to protect the eggs from damage and the hatchlings from predation.

INCUBATION AND HATCHLING DEVELOPMENT

D BROWN

Once laid, eggs should be removed for artificial incubation. Incubation should be in a mixture of water and vermiculite at a ratio of 1:3 by weight or 1:30 by volume. Eggs should be incubated at temperatures of 27oC–30oC. Incubation at room temperature may be successful but can take up to 270 days. At times, incubation periods follow no logic. In one season I placed three eggs—a clutch of one egg and a clutch of two eggs—laid only a few hours apart, into a communal incubation container. The first egg hatched at 90 days, the second at 110 days and the third after more than 190 days—despite all being incubated under the same conditions. Negligible swelling occurs during the incubation period. The fertility and viability of eggs may be indicated by their colour. Fertile eggs change from pink to lavender to grey as development progresses, whereas infertile eggs or eggs with early mortality are creamy white. There are no significant physical changes to eggs that indicate their fertility. An indication of fertility can be seen by the presence of blood vessels when candled in the first week or two. I follow one basic rule with this species—never throw an egg out unless it obviously has no chance of sustaining life. I only discard eggs that are broken, severely discoloured, smelly or wet. If normal looking eggs are opened up at a time period considered to be far in excess of usual timing, it is not unusual to find a fully formed and live juvenile inside. Hatching is not usually indicated by egg sweating. It appears that developed, but unhatched juveniles enter a dormant state in the egg and remain that way Cyrtodactylus tuberculatus hatchlings emerge from their eggs by kicking out the wall of the egg

page 251

until triggered to emerge. Hatching of other Cyrtodactylus species and Chameleon Geckos Carphodactylus laevis eggs may be triggered by the sudden wetting of well-advanced eggs—after 100 days of incubation—by placing wet sphagnum moss over the eggs. This has not resulted in accelerated hatching when I have tried it with the Coastal Ring-tailed Gecko C. tuberculatus, but I have tried limited numbers of eggs. Ring-tailed Gecko hatchlings do not gently slit the egg and emerge slowly like other geckos— the hatchling kicks or pushes a plug of shell out of the side of the egg and emerges. The allocation of gender in some overseas Cyrtodactylus species, such as Cyrtodactylus pulchellus, has been suggested to be the result of Type Two temperature dependent sex determination, which results in the production of females at higher temperatures. No studies have been carried out to indicate if this occurs in the Australian Ring-tailed Gecko species.

BREEDING RECORDS FOR RING-TAILED GECKO SPECIES Species C. tuberculatus and C. mcdonaldi

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

90−210 (27oC−30oC) >270 (room temperature)

43/85

Egg size (mm) Clutch Interclutch Interval (Mean or Range) Size (Days) (Length x Width) 2

46−150+

12 x 10

Hatchlings should remain in the incubation container for 12–24 hours after hatching. A hatchling left in the container any longer may potentially crack any remaining eggs when moving around. Substrate is generally unnecessary. The enclosure should be maintained at an ambient temperature of 26oC–28oC or may be heated via a heat cord or mat under part of the enclosure. Food should be offered 24 hours after hatching. Initially, items should measure approximately 25–35% of the hatchling’s head size and increase in size to 50–60% after two weeks. Frequent feeding will result in rapid growth rates. Suitable food items include crickets, cockroaches and slaters. The supply of a well supplemented diet and UV-B lighting is particularly crucial at this stage. I have experienced cases of metabolic bone disease associated with poor calcium supply from the parent once hatched, and poor calcium metabolism due to a lack of UV-B lighting. I have also raised hatchlings without UV-B with good success. It is possible that the calcium status of the parent plays the most important role by establishing or denying initial calcium stores within the egg.

HYBRIDISATION AND COLOUR VARIANTS Hybridisation and colour variants have not been recorded in these species.

LONGEVITY The Coastal Ring-tailed Gecko C. tuberculatus and the Inland Ring-tailed Gecko C. macdonaldi live moderately long lives. Their average life span is 7–10 years with a productive period of five years.

ACKNOWLEDGEMENTS I would like to thank Tremain Anderson, Michael Austin, Glen Shea, Fred Kraus, Lee Grismer and Nick Stock, among others, for their assistance with this chapter. page 252

S MACDONALD

Lucasium steindachneri

SMALL TERRESTRIAL GECKOS

This group currently comprises at least 36 species of gecko included in this chapter due to superficial similarities in their lifestyle and habits—18 Diplodactylus, 11 Lucasium and six Rhynchoedura species including— Fat-tailed Gecko Diplodactylus conspicillatus Helmeted or Mesa Gecko Diplodactylus galeatus Western Stone Gecko Diplodactylus granariensis Fine-faced Gecko Diplodactylus pulcher Tesselated Gecko Diplodactylus tesselatus Eastern Stone Gecko Diplodactylus vittatus Gibber Gecko Lucasium byrnei Beaded Gecko Lucasium damaeum Box-patterned Gecko Lucasium steindachneri Sand-plain Gecko Lucasium stenodactylum Beaked Gecko Rhynchoedura ornata

PRONUNCIATION

Following are the accepted pronunciations of the most common members of the small terrestrial gecko species. Diplodactylus conspicillatus Dip-low-dack-til-us con-spis-il-ah-tus Diplodactylus galeatus Dip-low-dack-til-us gal-ay-ah-tus Diplodactylus granariensis Dip-low-dack-til-us gran-ah-ree-en-sis Diplodactylus pulcher Dip-low-dack-til-us pool-ker Diplodactylus tesselatus Dip-low-dack-til-us tess-ell-ah-tus Diplodactylus vittatus Dip-low-dack-til-us vit-ah-tus Lucasium byrnei Loo-kay-see-um burn-ee Lucasium damaeum Loo-kay-see-um dah-mee-um Lucasium steindachneri Loo-kay-see-um stine-dack-ner-ee Lucasium stenodactylum Loo-kay-see-um stee-no-dack-til-um Rhynchoedura ornata Rink-ee-due-rah oar-nah-tah page 253

S MACDONALD D FISCHER

Diplodactylus conspicillatus

Diplodactylus granariensis granariensis

page 254

G SCHMIDA D FISCHER

Diplodactylus galeatus

G SCHMIDA

Diplodactylus pulcher

Diplodactylus vittatus

page 255

S EIPPER A ELLIOTT

Diplodactylus tessellatus

Lucasium damaeum

page 256

D FISCHER S EIPPER

Lucasium byrnei

J VAN DEN BERGH

Lucasium steindachneri

Diplodactylus ornatus

page 257

G SCHMIDA G STEPHENSON

Lucasium stenodactylum

J VOS

Lucasium occultum

Rhynchoedura ornata

page 258

A ELLIOTT S EIPPER

Diplodactylus calcicolus

Lucasium squarrosum

page 259

D FISCHER

Lucasium alboguttatum

DESCRIPTION ADULTS

D BROWN

Diplodactylus species are of medium size with robust and bulky bodies, short limbs and short tails. Lucasium species and Rhynchoedura species are elongate species with longer limbs and tails. They range in size—the smallest species Lucasium occultum measures 41mm SVL and the largest species Lucasium immaculatum measures 85mm SVL.   A typical Diplodactylus specimen measuring an average length of 50mm SVL will weigh an average of 3–4 grams. A typical Lucasium specimen measuring an average length of 50mm SVL will weigh an average of 2–3 grams. Colouration varies between and within species according to geographic origin and local habitat. Most species are brown with degrees of spotting, striping and mottling that reflects their terrestrial habits and need for cryptic colouration. Diplodactylus specimens feature short, swollen tails less than 80% of SVL that are stouter in the proportions than the tail and body. They do not possess preanal pores but do have a relatively high number of paracloacal spur components. Members of the Lucasium genus feature long and narrow tails 80–110% of SVL. They have preanal pores and fewer paracloacal spur components than Diplodactylus. Rhynchoedura possess 1–6 preanal pores and paracloacal spurs comprising 1–3 enlarged scales.

JUVENILES Hatchlings are generally a brighter version of the adult. They are 25−30% of average adult size.

Rhynchoedura ornata hatchling—note the rounded tail tip ball found in this species and some Lucasium hatchlings

page 260

SEXING

D BROWN

Ventral view of a female Diplodactylus tessellatus D BROWN

Ventral view of a male Diplodactylus tessellatus D BROWN

D BROWN

Small terrestrial geckos are moderately easy to visually sex as adults. Males of some species vary in colouration to females—Diplodactylus capensis males are cream and chocolate in colouration, whereas the females are pinker. A consistent resting colour dimorphism is common among Sand-plain Geckos L. stenodactylum, with females pinkish and paler than males. This is less prominent in active, feeding individuals and may be limited to specimens maintained in captivity. Adult males display obvious hemipenal bulges. Although these may reduce in size seasonally, a central depression and paracloacal spurs will remain. Females display some enlargement in this area, but it is less developed and without a central depression.

Lateral view of paracloacal spurs in a male Diplodactylus tessellatus

Lateral view of paracloacal spurs in a female Diplodactylus tessellatus

page 261

D BROWN D BROWN

D BROWN

Ventral view of a female Lucasium steindachneri

D BROWN

Ventral view of a male Lucasium steindachneri

Lateral view of paracloacal spurs in a male Lucasium steindachneri

Lateral view of paracloacal spurs in a female Lucasium steindachneri

Males possess unique paracloacal spurs positioned near the top of the hemipenal bulge near where it meets the hind limb. They consist of an arrangement of spines 2−3 times larger than the surrounding scales. The spine cluster varies according to species—Lucasium possess 2−5 and Diplodactylus has more than five enlarged scales. They are located in a similar position in females, but the spurs are rarely more than 50% larger than the adjacent body scales. Hemipenal transillumination can be used on hatchlings when they reach 30−50% of adult SVL and adults—particularly males whose hemipenes have reduced seasonally. However, use of this technique may be confusing with adults, as some females have a series of blood vessels that run either side of the cloaca that may be mistaken for hemipenal blood supply. Juveniles can be reliably visually sexed when they reach 60−70% of adult SVL which may occur at 6−12 months of age with adequate nutrition. page 262

D BROWN

Hatchling Box-patterned Geckos Lucasium steindachneri display colour dimorphism, but it is not consistent with differences in gender as adults. I believe it is a feature of dominance, with the darker specimens being the more dominant.

SUBSPECIES

J VAN DEN BERGH

Members of this group have been taxonomically classified both together and separate repeatedly over the past 20 years. Many species previously known as Diplodactylus are now allocated to the genus Lucasium. The new names of those specimens separated from the Diplodactylus genus are: Resting colour dimorphism in Lucasium Lucasium alboguttatum—formerly Diplodactylus stenodactylum, male (left) and female alboguttatus Lucasium byrnei—formerly Diplodactylus byrnei Lucasium damaeum—formerly Diplodactylus damaeus Lucasium immaculatum—formerly Diplodactylus immaculatus Lucasium maini—formerly Diplodactylus maini Lucasium occultum—formerly Diplodactylus occultus Lucasium squarrosum—formerly Diplodactylus squarrosus Lucasium steindachneri—formerly Diplodactylus steindachneri Lucasium stenodactylum—formerly Diplodactylus stenodactylus Lucasium wombeyi—formerly Diplodactylus wombeyi Rhynchoedura, formerly a monotypic genus, has recently been found to be made up of six cryptic species. Despite considerable variation within each species, little effort has been made by taxonomists to determine the need to split fairly obvious regional variations into possible species or subspecies, until recently. Further taxonomic work is currently underway.

Diplodactylus granariensis granariensis

page 263

Open spider burrow with lid folded back

IN THE WILD DISTRIBUTION AND HABITAT Small terrestrial geckos are distributed throughout most of mainland Australia within arid and semi-arid areas. Habitat includes organic debris, timber, stones and soil cracks. These geckos often shelter in disused reptile or spider burrows in areas that, in the daylight, can look incapable of providing habitat. At night, the same area may reveal thousands of spiders in perfectly camouflaged spider burrows, all of which may be used by geckos.

D FISCHER

Spider burrow being used by Rhynchoedura ornata

D BROWN

D BROWN D BROWN

Closed spider burrow

Habitat of Lucasium byrnei and Diplodactylus tessellatus, Fowlers Gap, New South Wales

page 264

D FISCHER

Habitat of Diplodactylus conspicillatus, Lucasium stenodactylum and Diplodactylus capensis, Exmouth, Western Australia

D BROWN

Some species are restricted in their range by specific habitat requirements—for example, the Helmeted Gecko D. galeatus primarily uses arid quartz outcrops. Others are restricted to very small geographical areas—for example, Lucasium occultum, Lucasium wombeyi, Diplodactylus fulleri, Diplodactylus kenneallyi and Diplodactylus mitchelli. All species forage by night in open ground and beneath foliage.

Habitat of Lucasium steindachneri, Rhynchoedura ormsbyi, Diplodactylus vittatus and Diplodactylus tessellatus, Alton, Queensland

page 265

S MACDONALD

Diplodactylus tessellatus

IN CAPTIVITY STATUS

S MACDONALD

Small terrestrial geckos are held in relatively low numbers in captivity at present. This is predominantly due to the lack of availability of captive bred stock, their small size and lack of bright colouration. These species are ideal for beginners, as they are relatively undemanding.

Rhynchoedura sexapora

page 266

HOUSING These geckos are generally entirely terrestrial and easy to maintain in captivity. Most have no particular specialist requirements and are good-natured.

INDOOR ENCLOSURES

D BROWN

Suitable enclosures include plastic tubs, commercial terrariums and fish tanks. These should measure a minimum of 4−5 SVL long x 4−5 SVL wide x 2−5 SVL high for housing pairs or trios. Excessively large enclosures are not required—these species use only a small floor space. Lids are essential, as despite being terrestrial in nature, these geckos are capable of climbing smooth surfaces with ease. Suitable substrate is sand at a depth of 1−5cm. Include bark pieces, small grass clumps and upturned terracotta saucers as hides. The substrate should be kept lightly moistened at one end for egg laying if a container is not provided—preferably under a hide. For species that naturally utilise them, you may provide depressions in the sand to act as artificial spider burrows—small pieces of plastic pipe, such as electrical conduit cut in half lengthwise, can be used. Pipe should form the roof of the burrow and be pushed into the sand. Alternatively, a finger hole pushed in moist sand may also be used. Vigorous heating is not generally required by these species. A heat mat or heat cord can be used under part of the enclosure floor if ambient temperatures are insufficient. Provide summer temperatures of up to 28oC−30oC for 10−14 hours daily and drop winter cooling temperatures to 15oC−20oC. Active cooling during winter is only considered necessary for breeding geckos. Juveniles do not need to be cooled over winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. The provision of UV-B light is not essential for these species and does not appear to impact growth or development if sufficient calcium and vitamin D3 are supplied via the diet. A bowl of fresh water should be available at all times. Alternatively, water can be supplied with regular misting.

Summary

Components of a suitable enclosure

A basic enclosure for small terrestrial geckos should include the following— • A substrate of sand 1−5cm deep, kept moist under a hide. • Bark pieces, upturned terracotta saucers and grass clumps. • Heat cord or a heat mat providing an enclosure temperature of 28oC−30oC in summer and 15oC−20oC in winter. • A nestbox. • A water bowl. page 267

OUTDOOR ENCLOSURES Despite the potential suitability of many species for outdoor housing in environments consistent with their natural range, these species are poor candidates for outdoor housing from an aesthetic perspective.

COMPATIBILITY Small terrestrial geckos are generally placid towards each other and display little, if any, aggression. They can be housed individually, in pairs or in groups consisting of one male with up to four females. Multiple males will tolerate each other in the absence of females. Males of different species can be housed together for display with few problems.

FEEDING

D BROWN

In the wild, small terrestrial geckos feed on small spiders, ants, cockroaches, crickets, termites and moths. They feed predominantly by foraging for insects among surface litter and on open ground. They will also pounce on insects that pass by their hides. In captivity, they will accept most small insects including crickets, cockroaches, termites, flies, maggots, slaters, moths and waxmoth larvae. Termites are an ideal food for juveniles as they are easy for them to catch, although pinhead crickets are easier for most keepers to supply. Termite addiction is particularly noted among some small terrestrial gecko species. The Fattailed Gecko D. conspicillatus feeds almost exclusively on termites in the wild. In captivity, this can be frustrating because termites are sometimes difficult to supply. They do not store well and desiccate after 24 hours in an enclosure. Attempts to convert the Fat-tailed Gecko D. conspicillatus onto other foods have varied in their success. Some individuals have readily changed their habits and will follow and strike small food items of similar size and colour to termites, whereas others have actively followed these items but failed to strike after sniffing them. This suggests that scent may play a partial role in food selection. Therefore, if you wish to broaden the diet for this species, scent alternative items with a mix of crushed termites and then wean the specimens off the scented food. Captive bred individuals are faster to wean than wild caught specimens. Adult wild caught Beaked Geckos Rhynchoedura sp. are also stubbornly addicted to termites and, in my collection, have steadfastly refused to accept any other food items. Surprisingly, hatchlings will readily accept pinhead crickets and will go on to accept small crickets as adults. However, these individuals should also be provided with termites on occasion to ensure their long-term survival— crickets seem to lack an important nutritional component that termites provide and longevity on an all cricket diet is much shorter than when termites are utilised. Diplodactylus conspicillatus eating termites

page 268

D BROWN

Oddly, the Fine-faced Gecko D. pulcher—another specialist termite feeder—will readily accept crickets with few problems and seem to have limited longterm growth issues. Insect food item size should measure approximately 60% of an individual’s head size. Food items should be lightly dusted with suitable calcium and vitamin D3 supplement in at least two out of three feeds. Adults should be fed every 4−7 days in summer and every 7−10 days in winter, although they may not accept food for short periods during this time. Juveniles should be fed every 2−4 days throughout the year.

BREEDING

D BROWN

In the wild and in captivity, small terrestrial geckos breed from September to February. Species from the north of the range may commence breeding later, from November to March. These species grow rapidly and with good feeding will reach adult size at 12–18 months of age. Individuals are capable of reproduction when they The visualisation of eggs is not always easy in Diplodactylus species such as reach 70−80% of adult SVL. Diplodactylus tessellatus Pair separation may be utilised and may allow for both males and females to rest prior to breeding, although it does not necessarily improve breeding outcomes. If cooling is practiced, it can be achieved by gradually reducing the number of heating hours and temperatures to the desired winter minimum. Generally, cooling using naturally lower ambient winter temperatures is sufficient and breeding may occur even if this is not intentionally provided. Regardless of the cooling technique used, or not used, most individuals will still breed at the same time each year. Courtship is rarely observed among these species due to their secretive nature. A male Eastern Stone Gecko D. vittatus has been observed biting the neck of a female in the chase period immediately preceding mating. The first eggs can be expected 4−8 weeks after the natural ambient temperature rises above 25oC. The visualisation of eggs is often much easier in Lucasium species such as Lucasium steindachneri

page 269

K GREISHAMER

A gravid female can be identified by a marked increase in girth. In some species, the eggs will be visible through her abdominal wall. A typical clutch for most species is two eggs, although sometimes only one egg may be laid. In captivity, up to five clutches are laid per year. The interval between clutches is usually 2.5−6 weeks. Prolific females should be separated from the males after 3−4 months of breeding to allow for total rest and to avoid the health problems associated with excessive breeding. Alternatively, cooling and the restriction of food may slow down breeding. In the wild, females will often lay their eggs in shallow scrapes dug in moist sand or on the sand surface under a Lucasium damaeum laying eggs hide structure. In captivity, females will lay their eggs in a similar manner but can be fussy and may lay their eggs in the open. If eggs are laid in the open, they may dehydrate quickly—especially if laid on dry sand. If they are markedly sunken and less than 24-hours-old they may recover if placed in a vermiculite tub with a piece of wet toilet tissue over them. They may take 3−5 days to rehydrate if the embryo is still viable. Even when ideal nesting sites are supplied, many females still repeatedly lay their eggs in unsuitable sites. My best breeding results have been achieved using small inverted takeaway containers placed upside down with the lid acting as the floor. A 1cm hole should be cut into the upper edge of this container, which is then filled two-thirds with moist peat moss or sphagnum moss. The container is then buried slightly so the entrance hole is level with the soil surface. I have found this method to be most successful with the Box Patterned Gecko L. steindachneri, the Tesselated Gecko D. tesselatus, the Fat-tailed Gecko D. conspicillatus and the Eastern Stone Gecko D. vittatus. Alternatively, an area of sand beneath a hide can be kept moist and checked regularly throughout the breeding season.

INCUBATION AND HATCHLING DEVELOPMENT Once laid, eggs should be removed for artificial incubation. Incubation should be in a mixture of water and vermiculite (or perlite) at a ratio of 1:1 by weight or 1:10 by volume. Eggs should be incubated at temperatures of 27oC−30oC. Incubation at room temperature may be successful, but will increase the length of the incubation period considerably and may leave the eggs more susceptible to fungal attack. Considerable egg expansion occurs during incubation with increases of up to 50% in width and 40% in length being typical. The eggshell may appear almost transparent when at peak pre-hatch expansion. If non-vented incubation containers are used, egg sweating will precede hatching by 24 hours. page 270

BREEDING RECORDS FOR SMALL TERRESTRIAL GECKO SPECIES Species

Clutch Size

Interclutch Egg size (mm) Interval (Mean or Range) (Days) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

D. conspicillatus

2

25

15.5 x 9.25

59−65 (28oC)

24−27/35

D. galeatus

2

18−37

16.5 x 8.5

36−55 (28oC)

25.7−27/45

D. pulcher

2

−

14−16 x 7.5−8

39−42 (28oC)

28 TL

D. byrnei

2

−

14−14.5 x 8.5−9.5

38−46 (28oC)

24−25

2−7

13−36

16 x 8

40−66 (28oC)

23−23.5 SVL

D. vittatus

2

12−42

15 x 8

50−60 (28oC) 64−68 (27oC)

20−30/45

D. tesselatus

2

21−29

13.5−14.5 x 6.5−8.5

50−60 (28oC)

21−24

L. stenodactylum

2

−

13 x 7

−

30 TL

L. occultum

2

42

11.9−13.1 x 5.9−6.9

67−69 (28oC)

23−24/42

L. steindachneri

2

−

14−15 x 8−8.5

56−75 (28oC)

25−27/41−49

L. dameum

2

14−35

−

30 (30.5oC) 40−50 (29oC)

18 SVL

R. ornatus

2

−

14 x 7

60−63 (28oC)

21/35

D. granariensis

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small holding container furnished a couple of small hides—such as egg carton segments, milk bottle lids or small terracotta saucers—and a small, shallow water bowl. Suitable substrate is sand. In contrast to many gecko species, small terrestrial gecko hatchlings appear more settled on sand than on unnatural substrates such as paper towel. I have not recorded sand impactions in these hatchlings. This may be helped by the delicate and precise nature of their feeding response compared to other gecko species. A heat cord or mat should be supplied to provide a basking temperature of 26oC−28oC. Food should be offered 24 hours after hatching. Initially, items should measure approximately 25−35% of the hatchling’s head size and be increased in size to 50−60% after two weeks. Suitable food items include pinhead crickets and termites for newborn hatchlings, and crickets of appropriate size for older hatchlings. page 271

M AU

D BROWN

Stripe width and margins can be selectively bred in Diplodactylus vittatus

D BROWN

An axanthic Diplodactylus vittatus (above) with a normal coloured specimen

Specimens can be selectively bred for an open (below) or closed box pattern in Lucasium steindachneri

HYBRIDISATION AND COLOUR VARIANTS Hybridisation has surprisingly not been recorded between these species. It is possible through selective breeding to establish genetic lines of some species with enhanced body stripes or spots. Within a single geographical population, this can be achieved with species such as the Eastern Stone Gecko D. vittatus, the Wheat Belt Stone Gecko D. granariensis and the Fine-faced Gecko D. pulcher. Pattern style can also be selectively bred in species such as the Box-patterned Gecko L. steindachneri. Axanthic specimens of the Eastern Stone Gecko D. vittatus have been bred overseas.

LONGEVITY Small terrestrial geckos live moderately long lives. Their average life span is 5−8 years in captivity with a productive period of 3−4 seasons.

ACKNOWLEDGEMENTS I would like to thank John McGrath, Sav Timpano, Mark van Ijzendoorn, Pete Nunn, and Manfred Au, among others, for their assistance with this chapter.

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S MACDONALD

Uvidicolus sphyrurus

THICK-TAILED GECKOS

The thick-tailed gecko group comprises two genera with four species as follows— Western Thick-tailed Gecko or Barking Gecko Underwoodisaurus milii Eastern Thick-tailed Gecko or Barking Gecko Underwoodisaurus ‘husbandi’ Pilbara Barking Gecko Underwoodisaurus seorsus Border Thick-tailed Gecko or Granite-Belt Thick-tailed Gecko Uvidicolus sphyrurus

PRONUNCIATION

S MACDONALD

Following are the accepted pronunciations of the thick-tailed gecko species. Underwoodisaurus milii Under-wood-ee-sore-us mill-ee-eye Underwoodisaurus ‘husbandi’ Under-wood-ee-sore-us hus-band-ee Underwoodisaurus seorsus Under-wood-ee-sore-us see-oar-suss Uvidicolus sphyrurus You-vid-ee-cole-us s-fy-roo-rus

Underwoodisaurus ‘husbandi’

page 273

G STEPHENSON J VOS

Underwoodisaurus ‘husbandi’

Underwoodisaurus milii

page 274

S EIPPER

Uvidicolus sphyrurus

DESCRIPTION ADULTS Thick-tailed geckos are of medium size with plump bodies, broad heads and fattened carrotshaped tails. They range in size—the smallest species the Border Thick-tailed Gecko U. sphyrurus measures 70mm SVL. The largest species, the Western Thick-tailed Gecko U. milii measures 100mm SVL. A typical specimen measuring an average length of 85mm SVL will weigh an average of 11−12 grams. Colouration varies—the Western Thick-tailed Gecko U. milii and the Eastern Thick-tailed Gecko U. ‘husbandi’ range from pale pink-brown to dark purple-brown. They display cream or white spots centered over dorsal tubercles, often arranged in transverse patterns or thick bands. The original tail is usually darker in colour than the body and features 5−6 white bands. A regenerated tail is much paler in colour than an original tail and the patterning upon it is generally restricted to pale mottling. The Border Thick-tailed Gecko U. sphyrurus is a more uniform grey-brown colour with darker mottling than the Western Thick-tailed Gecko U. milii and small pale spots centered on the tubercles. The tail is squarer than in the Western Thick-tailed Gecko U. milii and features four cream bands.

JUVENILES Hatchlings are a brighter version of the adult with darker patterning and more distinctive banding and patterns. Hatchlings develop adult colouration from approximately four months of page 275

D FISCHER D BROWN

S EIPPER

Hatchling Underwoodisaurus milii

Hatchling Underwoodisaurus ‘husbandi’

Hatchling Uvidicolus sphyrurus

age, with full adult colouration attained by eight months of age. Hatchlings are generally 25−40% of average adult size and reach adult size in 9−12 months with adequate nutrition.

SEXING Thick-tailed geckos are moderately easy to visually sex as adults. Males are generally slightly smaller than females. Adult males display obvious hemipenal bulges. Adult males do not display consistently larger or more ornate paracloacal spur components than females but the number of components is larger, resulting in spurs that are more protuberant in males. Hemipenal transillumination can be used on specimens once they reach 20mm SVL. The hemipenes in juvenile males will be visible as two distinct red spots. Juveniles can be reliably visually sexed once they have reached 60−70% of adult SVL which can occur at 6−12 months of age. Juveniles less than six months of age display visible differences in hemipenal structures between the sexes. Males display a rectangular or wide, oval-shaped hemipenal area with pronounced tubercles, whereas this area is more triangular in females, with smaller tubercles. These differences are not always 100% reliable. page 276

D BROWN

Lateral view of paracloacal spurs in a male Underwoodisaurus ‘husbandi’

Lateral view of a juvenile female Underwoodisaurus ‘husbandi’ D BROWN

D BROWN

Ventral view of a juvenile male Underwoodisaurus ‘husbandi’

D BROWN

D BROWN

Lateral view of an adult female Underwoodisaurus ‘husbandi’

D BROWN

Ventral view of an adult male Underwoodisaurus ‘husbandi’

Lateral view of paracloacal spurs in a female Underwoodisaurus ‘husbandi’

page 277

SUBSPECIES

B LOVE/R MACKINTOSH

Homogenous (same size) dorsal tubercles of Underwoodisaurus milii

Underwoodisaurus seorsus

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D BROWN

The genus Underwoodisaurus has been subject to much taxonomic confusion for many years. Members of this genus were placed in the genus Nephrurus with the knob-tailed geckos for many years. As this change was beginning to earn acceptance within the herpetological community and was being used in common text, the Border Thick-tailed Gecko U. sphyrurus was placed in the monotypic genus Uvidicolus. For this to occur, the genus Underwoodisaurus had to be reapplied to all other thick-tailed geckos. At the time of publication, work had not been carried out to determine the validity of the separation by Wells and Wellington (1985) of the Thick-tailed Gecko U. milii into the Western Thick-tailed Gecko U. milii—representing the western populations—and the Eastern Thick-tailed Gecko U. ‘husbandi’—representing the eastern populations.

Heterogenous (different sizes) dorsal tubercles of Underwoodisaurus ‘husbandi’

The type specimen for the Thick-tailed Gecko U. milii was from Shark Bay, Western Australia, and all other specimens were assigned to this species regardless of their origin. The Eastern Thick-tailed Gecko U. ‘husbandi’ was separated morphologically on the basis of its smaller overall size and heterogenous tubercles on the back and tail, of which few are arranged in transverse lines. The Western Thick-tailed Gecko U. milii is larger than the Eastern Thick-tailed Gecko U. ‘husbandi’ and displays prominent, enlarged, homogenous conical dorsal tubercles arranged in transverse rows—particularly on the tail. Chromosomal work confirms deep genetic divergences between eastern and western populations as well as some interesting divergences within the eastern populations. It is hoped this DNA evidence will be coupled with morphological evidence so the matter can be finally clarified. Recently, taxonomic work has been carried out on isolated and unique specimens from the Pilbara region of Western Australia. These are morphologically distinct and have been recently named the Pilbara Barking Gecko U. seorsus (Doughty and Oliver 2011). Interestingly, like the Eastern Thick-tailed Gecko U. ‘husbandi’, they possess heterogenous dorsal tubercles, not homogenous ones like their geographically closer family members the Western Thick-tailed Gecko U. milii. There are no recognised subspecies of the Border Thick-tailed Gecko U. sphyrurus.

IN THE WILD DISTRIBUTION AND HABITAT

D BROWN

The Western Thick-tailed Gecko U. milii and the Eastern Thick-tailed Gecko U. ‘husbandi’ are distributed across the southern half of Australia from east to west. Although their range is large, it is restricted to specific habitats within it including dry sclerophyll forest, saltbush, mallee and desert. Within these habitats they are most commonly found in sandstone, limestone and granite outcrops where they shelter beneath rocks and fallen timber and within gaps in rock exfoliations. They are most prevalent in areas with cooler ambient temperatures, although desert forms do occur. It is not uncommon for these geckos to occur in groups and multiple animals (up to 13 have been recorded) are often found under a single hide site. Field studies I was involved with in Victoria showed that choice of exfoliated rock slabs as hide sites was based on a combination of factors including a preference for narrow spaces, larger rocks, horizontal rocks, protected sites and an absence of prior predator presence. Although thicker rocks provided more heat retention, they were not preferentially chosen. Hide sites were also shared with Christinus marmoratus. Three Underwoodisaurus ‘husbandi’ and two Christinus marmoratus sharing a refuge under a rock exfoliation (upper rock removed), Mount Korong, Victoria

page 279

D FISCHER D BROWN

J VOS

Habitat of Underwoodisaurus ‘husbandi’, the Warrumbungles, New South Wales

Habitat of Uvidicolus sphyrurus, Tenterfield, New South Wales

Habitat of Underwoodisaurus milii, Mount Cooke, Western Australia

The Border Thick-tailed Gecko U. sphyrurus is very restricted in its habitat and range. It is found in the cool highlands of the granite belt of New England in New South Wales and in areas near Stanthorpe and Amiens in Queensland. Habitat includes shaded exfoliations and under soil embedded stones or logs. The Pilbara Barking Gecko U. seorsus is found in the rocky, Spinifex country of the Hammersley Ranges in the Pilbara, Western Australia. page 280

S EIPPER

Underwoodisaurus ‘husbandi’

IN CAPTIVITY STATUS

S EIPPER

The Western Thick-tailed Gecko U. milii and the Eastern Thick-tailed Gecko U. ‘husbandi’ are among the most common Australian geckos in captivity. Despite their relatively low price and sensitivity to heat, they remain popular with beginners and experienced keepers. In comparison, the Border Thick-tailed Gecko U. sphyrurus is kept in extremely low numbers.

Underwoodisaurus milii

page 281

G GAIKHORST S MACDONALD

Underwoodisaurus milii

Uvidicolus sphyrurus

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D BROWN

Components of a suitable enclosure

HOUSING Thick-tailed geckos are terrestrial species, easy to maintain and opportunistic. They can be kept in a variety of enclosures provided they allow for ambient cooling. Their heat sensitivity may lead to some specific requirements in captivity, depending on the geographical location of where they are being maintained.

INDOOR ENCLOSURES Suitable enclosures include plastic and commercial terrariums, fish tanks and plastic tubs. Many successful breeders maintain this species in enclosures at ground level or in the cooler parts of the reptile room to cater for their heat intolerances. Enclosures should measure a minimum of 3 SVL long x 3 SVL wide x 2−3 SVL high. Enclosure height is far less important. Excessively large enclosures will make it difficult for occupants to catch insects before they have shed their calcium and vitamin dusting powders. Lids are essential as these species can climb silicone sealant in the corner of tanks and in roughened plastic tubs—however some keepers forgo lids with no issues. Suitable substrate is sand or a mixture of sand and peat moss 1−3cm deep. Depth is not important as thick-tailed geckos do not burrow, however they will push aside substrate under stable hides to create hollows. Suitable furnishings include hides such as broad bark slabs, thin granite slabs, terracotta tiles and terracotta and plastic dishes. Multiple layers will allow individuals to rest alone, however 2−3 specimens will often jam tightly together into a single space. Hides should measure approximately 1.5−2cm wide. These species will also use a moist hide as a nest site during the breeding season. Thick-tailed geckos are opportunistic when it comes to selecting a home niche, preferring areas where temperatures are cooler. Heating is not required by these species. A substrate temperature of 22oC−26oC provided for 10−14 hours daily in summer is suitable—temperatures above 28oC are not recommended. A heat mat or heat cord can be used for heating if the local ambient temperature is not sufficient. page 283

Temperatures can drop to 15oC−20oC in winter. More extreme cooling is suggested by some breeders of the Border Thick-tailed Gecko U. sphyrurus, which allow a drop as low as 4oC by locating by specimens in a polystyrene box in a shaded area outside during winter. Whether this is necessary for better breeding results or not is unproven—the species has bred in small numbers without this. Juveniles should ideally be maintained at 25oC−26oC through the year. The provision of UV-B light is not essential for these species, although it may benefit juveniles and breeding females. UV-B lamps of 5% UV-B are ideal, although I have not used them with these species. It may not be required if adequate calcium and vitamin D3 is provided through the diet. A bowl of water should be available at all times, although the enclosure can also be misted twice a week.

Summary A basic enclosure for thick-tailed geckos should include the following— • A susbtrate of sand or a mixture of sand and peat moss 1−3cm deep. • Overlapping horizontal slabs providing numerous hides 1.5−2cm wide or a dry hide site such as an upturned terracotta saucer. • A moist hide site or nestbox. • A water bowl.

OUTDOOR ENCLOSURES

J VOS

These species are ideally suited to outdoor housing in areas that reflect their natural origin. Suitable enclosures include pits or large plastic tubs. Although they thrive in this type of setup, these enclosures are not particularly aesthetically pleasing due to the cryptic nature of these species. Rock exfoliations or timber slabs may be used as furnishings. Care must be taken to ensure that adequate drainage is available in inclement weather. Eggs may hatch in situ but hatchlings may be eaten by large adults.

Underwoodisaurus milii

page 284

S EIPPER

Underwoodisaurus ‘husbandi’ juvenile

COMPATIBILITY In the wild, thick-tailed geckos often occur in social groups, with numerous individuals sharing suitable hide sites. In captivity, they may be housed as pairs, trios or large groups. Multiple Border Thick-tailed Gecko U. sphyrurus males can be housed together and appear to be compatible in the long-term.

FEEDING In the wild, thick-tailed geckos feed on small spiders, cockroaches, crickets, moths and any other arthropods on offer. They feed by actively chasing food items spotted from a distance, but will also sit and wait to ambush items. In captivity, they will accept any terrestrial insect including crickets and cockroaches. Insect food item size should measure approximately 60% of an individual’s head size. Food items should be lightly dusted with suitable calcium and vitamin D3 supplements in at least two out of three feeds. Adults should be fed every 4−7 days in summer and every 7−10 days in winter, although they may not accept food for short periods during this time. Juveniles should be fed every 2−4 days throughout the year. Most thick-tailed geckos will accept food while the keeper observes and some will take food directly from forceps. Occasionally, individuals within a pair or group may fight over food items, vocalising with loud squeals and squeaks, resulting in the food item being torn apart and one individual missing out and needing to hunt elsewhere. To prevent dominance during feeding, each individual should be supplied with 4−6 food items.

BREEDING In the wild, breeding occurs from September to March. Specimens from southern localities may commence breeding later and finish earlier due to the cooler weather. In captivity, breeding occurs from September to March. page 285

D BROWN

Underwoodisaurus ‘husbandi’, sub adult

C HILL

Individuals are capable of reproduction when they reach 60–70% of adult SVL which may occur at 12 months of age. Pair separation is not essential for breeding success and pairs may be maintained together throughout the year. Out of season breeding is rare—females can rest in the non-breeding season in the presence of males. Cooling is not necessary in areas where local ambient temperature changes are sufficient. However, it can be achieved by gradually reducing the number of heating hours and temperatures to 15oC−18oC by day and 10oC−15oC by night. Courtship may be observed, although it can be secretive and occur within hides or within a nesting site. It is usually short, with the male waving his tail and sniffing the female. Mating is prolonged and lasts more than 45 minutes. During mating, the male grips the female, grabbing the skin of her neck in his jaws. He then positions himself partially on top of, and beside the female. The first eggs can be expected six weeks after ambient temperatures rise above 20oC. A gravid female can be identified by a marked increase in girth. The eggs will be visible as distinct shapes through her abdominal wall. A typical clutch is two eggs, although on occasion only one may be laid. Breeding in the first season can be poor—the best breeding results are in the second and subsequent seasons. The eggs are ovalshaped and leathery-shelled. They are moist when first laid, which can cause the substrate to stick to them.

Mating hypomelanistic Underwoodisaurus ‘husbandi’

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S RANSOM

A typical clutch of Underwoodisaurus milii eggs

Eggs are clearly visible through the abdominal skin in this Underwoodisaurus milii female

An Underwoodisaurus ‘husbandi’ female laying in moist peat moss

In captivity, 3−5 clutches are laid each year. The interval between clutches is usually 4−8 weeks. In captivity, nest facilities are easy to provide. In some regions, Eastern Thick-tailed Gecko U. ‘husbandi’ have been recorded nesting communally with up to 20 eggs in a single site—it is not clear if this represents a preferred behaviour or is simply due to a lack of suitable nesting sites. These species will nest in any enclosed container of moist substrate or in a moist corner of the enclosure. Suitable egg laying substrate is a mixture of coir peat and sand at a ratio of 50:50 or just moistened coir peat. It should be moist enough that it sticks together temporarily when squeezed, but not so wet that water runs out of it. Nesting is usually preceded by the digging of several test holes a few days beforehand. The eggs are usually laid at the bottom of the container.

INCUBATION AND HATCHLING DEVELOPMENT Once laid, eggs should be removed for artificial incubation. Incubation should be in a mixture of water and vermiculite at a ratio of 1:1 by weight or 1:10 by volume. Incubation is relatively simple and without problems in these species. Unusually for a heat sensitive species, the eggs may be incubated at temperatures of 28oC−29oC. They can also be left at room temperature to hatch naturally with equal success, however the incubation period will be considerably longer. page 287

D BROWN

Hatchling Underwoodisaurus ‘husbandi’ in defensive posture

Considerable egg expansion occurs during incubation with increases of up to 40% in width and 25% in length being typical. If non-vented incubation containers are used, egg sweating will precede hatching by 24 hours. Western Thick-tailed Gecko U. milii specimens have longer incubation periods than Eastern Thick-tailed Geckos U. ‘husbandi’.

BREEDING RECORDS FOR THICK-TAILED GECKO SPECIES Clutch Size

Interclutch Interval (Days)

Egg size (mm) (Mean or Range) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

U. milii and U. ‘husbandi’

2

29−50

19.5−24 x 11.5−15

42−82 (26.5oC−29oC)

28−39/51−72

U. sphyrurus

2

−

20.6−25.6 x 9.6−10.5

59−73 (27oC−29oC)

35−39

SPECIES

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small holding container furnished with a small hide—such as a toilet roll cut lengthwise or similar—and a water bowl. Substrate is unnecessary but some breeders use moistened beach sand with no issues. Heating is not required if the ambient room temperature is between 20oC−26oC. Food should be offered 24 hours after hatching. Initially, items should measure approximately 25−35% of the hatchling’s head size and be increased in size to 50−60% after two weeks. Suitable food items include small crickets, small cockroaches and slaters. page 288

HYBRIDISATION AND COLOUR VARIANTS

I LEVENTHAL

S EIPPER

Hypomelanistic morph of Underwoodisaurus ‘husbandi’

Hybridisation has not been recorded in these species. It is not sure if any hybrids have occurred between eastern and western specimens or if this is possible. A number of selected colour mutations, sometimes common within wild populations, have been established in captivity. Hypomelanistic specimens are the most common—I have observed up to 5% in wild specimens in some areas of Victoria. These geckos are generally paler in overall colouration, with the depth of their colour varying according to the original colour form the Amelanistic morph of Underwoodisaurus milii specimen was bred from. They may range in colour from pink to pale tan. This mutation appears to be recessive in its mode of inheritance. Amelanistic specimens are essentially yellow and white in colour. These geckos are yet to be well established in captivity. They appear to be recessive in their mode of inheritance. Patternless specimens have also been observed but are even less well established in captivity. These individuals vary in their appearance—some may display diffuse spots and others may lack spots completely. The mode of inheritance is unclear.

LONGEVITY Thick-tailed geckos live long lives. The average life span is 10−12 years with a productive period of 6−8 years. Some exceptional Western Thick-tailed Gecko U. milii specimens are still breeding at 18 years of age.

ACKNOWLEDGEMENTS I would like to thank Rob Porter, Sav Timpano, John McGrath, Richard Wells, Clint Hill and Scott Eipper, among others, for their assistance with this chapter. page 289

G SCHMIDA

Oedura marmorata

VELVET GECKOS

The velvet gecko group comprises at least 16 species as follows— Attenborough’s Velvet Gecko Oedura attenboroughi Northern Velvet Gecko Oedura castelnaui Northern Spotted Velvet Gecko Oedura coggeri Fringe-toed Velvet Gecko Oedura filicipoda Dotted Velvet Gecko or Jewelled Velvet Gecko Oedura gemmata Gracile Velvet Gecko Oedura gracilis Quinkan Velvet Gecko Oedura jowalbinna Marbled Velvet Gecko Oedura marmorata Ocellated Velvet Gecko Oedura monilis Southern Spotted Velvet Gecko Oedura tryoni Reticulated Velvet Gecko Hesperoedura reticulata Clouded Gecko Amalosia jacovae Lesueur’s Velvet Gecko Amalosia lesueurii Slim Velvet Gecko Amalosia obscura Zig Zag Velvet Gecko Amalosia rhombifer Robust Velvet Gecko Nebulifera robusta

PRONUNCIATION Following are the accepted pronunciations of the most common members of the velvet gecko species. Oedura attenboroughi Eh-due-rah att-en-bur-ow-ee Oedura castelnaui Eh-due-rah cas-tell-now-ee Oedura coggeri Eh-due-rah cog-er-ee Oedura filicipoda Eh-due-rah fill-is-ee-poh-dah Oedura gemmata Eh-due-rah gem-ah-tah Oedura gracilis Eh-due-rah grah-sil-us Oedura marmorata Eh-due-rah mar-more-ah-tah Oedura monilis Eh-due-rah mon-eye-lis Oedura tryoni Eh-due-rah try-on-ee Amalosia lesueurii Ay-mal-oh-see-ah les-you-ree-eye Amalosia rhombifer Ay-mal-oh-see-ah rom-biff-er Nebulifera robusta Neb-you-liff-er-ah row-bus-tah page 290

G SCHMIDA S MACDONALD

Oedura attenboroughi

Oedura tryoni

page 291

S EIPPER M ANTHONY

Oedura castelnaui

G SCHMIDA

Oedura coggeri

Oedura filicipoda

page 292

S EIPPER G SCHMIDA

Oedura coggeri

G SCHMIDA

Oedura gemmata

Nebulifera robusta

page 293

S EIPPER G SCHMIDA

Oedura marmorata

Oedura marmorata

page 294

S MACDONALD D BROWN

Oedura gracilis

Oedura tryoni

page 295

S EIPPER S MACDONALD

Amalosia lesueurii

Oedura attenboroughi

page 296

S MACDONALD S MACDONALD

Oedura monilis, ‘coastal’ form

S MACDONALD

Amalosia rhombifer

Oedura gemmata

page 297

S EIPPER G SCHMIDA

Nebulifera robusta

S MACDONALD

Oedura gracilis

Amalosia jacovae

page 298

S EIPPER

Oedura monilis, ’inland’ form

page 299

DESCRIPTION ADULTS Velvet geckos are of small to medium size with either slender, elongate bodies or robust, bulky bodies. Their common name is derived from the small, flat, homogenous scales on their body, which have a soft, velvety texture. Their tails are thick and either slender and rounded or robust and flattened. The tail is believed to act as a nutritive store in periods of low food supply. They range in size—the smallest species the Lesueur’s Velvet Gecko A. lesueurii measures 55mm SVL and the largest species the Fringe-toed Velvet Gecko O. filicipoda measures 105mm SVL. The majority of species in this group measure 70–90mm SVL. A typical specimen measuring an average length of 80mm SVL will weigh an average of 13–14 grams. Colouration varies in some species according to geographic region. Some also vary in size, tail shape and in the distribution of banding and spotting. Most species in this group display prominent patterns consisting of spotting, blotches and bands.

JUVENILES

S MACDONALD

Adult Oedura coggeri D BROWN

Hatchling Oedura coggeri D BROWN

D BROWN

Hatchlings are generally a brighter, more spectacularly coloured version of the adult. Colouration as juveniles varies and may not indicate expected adult colouration—particularly among the larger spotted and striped species.

Hatchling Oedura attenboroughi

Adult Oedura attenboroughi

Hatchling Southern Spotted Velvet Geckos O. tryoni, Attenborough’s Velvet Geckos O. attenboroughi, Fringe-toed Velvet Geckos O. filicipoda, Northern Spotted Velvet Geckos O. coggeri, Gracile Velvet Geckos O. gracilis, Jewelled Velvet Geckos O. gemmata, Marbled Velvet Geckos page 300

D BROWN

S MACDONALD

Hatchling Oedura marmorata

Adult Oedura marmorata

O. marmorata, Ocellated Velvet Geckos O. monilis and Northern Velvet Geckos O. castelnaui usually display bright contrasting banding and spotting, which although placed in similar orientation to how they will appear as adults, is brighter coloured, lacks fine detail and is usually located on a plain, dark background. Adult colouration begins to develop at 3−4 months of age and is generally complete when the juvenile reaches 50−70% of adult SVL. Hatchlings of medium-sized species, such as the Southern Spotted Velvet Gecko O. tryoni and the Robust Velvet Gecko N. robusta, are generally 30% of average adult size, measuring 35−40mm with an average total length of 60−65mm.

SEXING

D BROWN

D BROWN

Velvet geckos are moderately easy to visually sex as adults. Adult males display obvious hemipenal bulges that appear as a rounded swelling of the tail base with a distinctive central depression. Females may display a slight bulge at the tail base but it is always without a central depression. Males possess paracloacal spurs positioned at the top of hemipenal bulge. They consist of an arrangement of spines 2−3 times larger than the surrounding scales.

Ventral view of a male Oedura marmorata

Ventral view of a female Oedura marmorata

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D BROWN

Lateral view of paracloacal spurs in a male Oedura marmorata

Lateral view of paracloacal spurs in a female Oedura marmorata D BROWN

The spine cluster varies between species—in larger species such as the Southern Spotted Velvet Gecko O. tryoni, the Marbled Velvet Gecko O. marmorata and the Ocellated Velvet Gecko O. monilis it appears as a single large rounded scale, sometimes with a smaller scale adjacent to it. In smaller, slender species, such as the Lesueur’s Velvet Gecko A. lesueurii, it may appear as a cluster of brighter white fan-shaped scales which protrude more than the body scales. Females may possess a smaller paracloacal spur, however the Lateral view of paracloacal spurs in a male component scales are no more than 75% larger Amalosia lesueurii than the body scales. Hemipenal transillumination can be used on adults and on hatchlings when they reach 25% of adult SVL. Juveniles can be reliably visually sexed once they reach 60% of adult SVL, which can occur from 8−18 months of age with adequate nutrition.

SUBSPECIES The genus Oedura has traditionally encompassed all ‘velvet’ geckos, despite their considerable differences in size and appearance. In 2012, Oliver et al, separated Oedura into four genera based on morphological and DNA evidence. Nebulifera contains only one species—robusta. Amalosia contains the four species—lesueurii, rhombifer, jacovae and obscura. Hesperoedura contains only one species—reticulata. All other members of the former genus Oedura remain in that genus. There are no recognised subspecies within the Oedura group. However, significant geographical races have been recognised—the most noticeable being the Marbled Velvet Gecko O. marmorata, which is also the most widespread species within the group. It may comprise 6−8 currently unrecognised species. Variation also occurs in the Ocellated Velvet Gecko O. monilis. The ‘inland’ population of this species displays the typical colouration of the type specimens. However a ‘coastal’ population on Queensland’s central and north coast, from Rockhampton to Proserpine, is superficially similar to page 302

G SCHMIDA

Oedura marmorata—this species may comprise a number of unrecognised species

the Ocellated Velvet Gecko O. monilis but displays obscure smaller spotting with some coalescing into thin banding. Another distinct form of Oedura similar to the Ocellated Velvet Gecko O. monilis occurs in central western Queensland and towards the coast as far as Proserpine—the name Attenborough’s Velvet Gecko O. attenboroughi has been applied to this species. Some herpetologists consider this population invalid and merely a variation of the Marbled Velvet Gecko O. marmorata—a quite obvious error, as both adults and hatchlings clearly bear greater resemblance to the Ocellated Velvet Gecko O. monilis than to the Marbled Velvet Gecko O. marmorata. They are readily distinguished from both the Ocellated Velvet Gecko O. monilis populations and the Marbled Velvet Gecko O. marmorata by the following features—a variable dark midline stripe or series of blotches from the tip of the nose to the crown of the head, variable white ‘temple’ spots, 5−6 coalesced paired spots on a dark background along the dorsal spine (the first forming a crescent at the base of the neck) and a variable series of small white spots halfway between the dorsal midline and lateral midline. The Jewelled Velvet Gecko O. gemmata displays considerable variation in overall size and patterning as a hatchling. Classic Jewelled Velvet Geckos O. gemmata produce unpatterned young, whereas populations from the east of Katherine at Conway Station, Northern Territory, display banding and spotting as hatchlings. The Jewelled Velvet Gecko O. gemmata should be considered a species complex requiring more work. The Gracile Velvet Gecko O. gracilis also displays considerable variation and comprises a number of undescribed species. Dr Gavin Bedford has proposed Oedura ‘mitralini’ for one population. The Robust Velvet Gecko N. robusta varies between the eastern coastal populations, which display a separated diamond pattern along the back, and the inland rock inhabiting populations from Duaringa to Roma, Queensland, that display a joined up diamond pattern that forms a broad zigzag. The Southern Spotted Velvet Gecko O. tryoni also varies considerably between populations with variations in body size, spot size, coalescing of spots and background colour. Distinct variation is noted between specimens from the southern highlands of Queensland, south-east Queensland, western Queensland and the central highlands of Queensland. Other than the above mentioned, most variation within Oedura geckos is based on background colour and colour intensities. page 303

J VOS S MACDONALD

S MACDONALD

Habitat of Oedura marmorata, Mount Magnet, Western Australia

Habitat of Oedura monilis and Oedura marmorata, Glenmorgan, Queensland

Habitat of Oedura coggeri, Oedura castelnaui and Amalosia rhombifer, Undara Volcanic National Park, Queensland

IN THE WILD DISTRIBUTION AND HABITAT

Velvet geckos are endemic to Australia and are among one of the most widespread gecko groups distributed throughout the country, although their individual ranges may be small. They are not found in Tasmania. Habitat includes arboreal settings and rocky areas. They shelter in rock cracks and crevices, under loose bark or within tree hollows—some have even adapted to live close to human dwellings. Many isolated northern species inhabit sandstone caves. Velvet geckos are semi-arboreal and forage at night on the surface of the rocks and trees in which they live—they also venture onto the ground. page 304

IN CAPTIVITY STATUS Of the 16 recognised velvet gecko species approximately 50% are common in captivity, 25% are rare and the remainder are not available as captive specimens. A number of unnamed species are held in small numbers by some enthusiasts. Wild caught collections of rare Odeura species at zoological institutions show they are no more difficult to establish than more common species. Hopefully, some of these may enter private collections in the future.

HOUSING Velvet geckos are primarily arboreal and easy to maintain due to their opportunistic nature. Despite being predominantly arboreal, they will accept terrestrial and arboreal-style enclosures— an ideal enclosure will cater for both activities.

INDOOR ENCLOSURES Suitable enclosures include plastic and commercial terrariums, fish tanks and plastic tubs. These should measure a minimum of 3–5 SVL long x 3–5 SVL wide x 3–5 SVL high. Extra height allows for better placement of vertical structures. Enclosure space is used well and, therefore does not need to be particularly large. Excessively large enclosures will make it more difficult for the occupants to catch insects before they have rid themselves of calcium and vitamin powders dusting powders. Lids are essential, as these species are superb climbers and will easily scale glass surfaces with ease and at high speed. In my experience, the Robust Velvet Gecko N. robusta is the most escapeprone species and can leap or run up glass with ease. The Southern Spotted Velvet Gecko O. tryoni and the Marbled Velvet Gecko O. marmorata often climb on keepers during routine cage maintenance. Substrate is not overly important for these arboreal species. Suitable substrate is sand or loose, clean leaf litter, which will stop faeces from sticking to the enclosure floor. Provide broad bark slabs, bark rolls, hollow logs, pieces of timber, bamboo pieces and cardboard rolls as hides and for stimulation. The spaces between layers should measure 0.5–1cm in width. The majority—up to 70%—can be placed vertically with the remainder on the enclosure floor. Multiple layers can be provided to allow individuals to rest separately, however 2−3 specimens will often jam together into a single bark roll or gap between hide layers. A predominance of vertical components will reduce faeces from building up over time, allowing them to fall to the enclosure floor—this is important as these species often defecate where they sleep. Some velvet gecko species love to bask. In the wild, they presumably bask in the openings of rock crevices or under bark on the side of trees. Temperatures of 28oC−30oC are recommended for 10−14 hours per day in summer. Winter temperatures can drop to 15oC−20oC. A low wattage basking lamp can be used for heating. Alternatively, heat cord or heat tape, placed vertically along a wall or under the floor with a hide site covering this area, can be used. Active cooling during winter is only considered necessary for breeding geckos. Juveniles do not need to be cooled over winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. page 305

D BROWN

The provision of UV-B light is not essential for these species, although it may benefit juveniles and breeding females. UV-B lamps of 5% UV-B are ideal. It may not be required if adequate calcium and vitamin D3 is provided through the diet. A water bowl should be provided at all times although some keepers will provide moisture by lightly misting the enclosure walls once or twice a week.

Summary A basic enclosure for velvet geckos should include the following— • A thin substrate of sand or light leaf litter. • Horizontal or vertical slabs, providing numerous spaces approximately 1cm wide. • An appropriate heat pad, heat cord or small heat lamp providing temperatures of 28oC−30oC for 10−14 hours per day in summer and temperatures of 15oC−20oC in winter. • A moist hide site or nestbox. • A water bowl.

Components of a suitable enclosure

OUTDOOR ENCLOSURES Some species are ideally suited to outdoor housing in areas similar to their natural habitat. Suitable enclosures include suspended style enclosures. They can be mounted on the walls of a home under the eaves—this will provide some protection from the elements. Enclosures mounted near outdoor lighting may benefit from additional dietary components of moths and other insects attracted to the lighting.

COMPATIBILITY Velvet geckos vary greatly in their temperament and shyness. Generally, they can be housed in pairs or groups of males with multiples females—the success of this depends on the species and the individuals within that group. I have noted female-to-female aggression among the larger species such as the Southern Spotted Velvet Gecko O. tryoni and some Ocellated Velvet Geckos O. monilis—it is rarely observed in my collection among Robust Velvet Geckos N. robusta and Northern Velvet Geckos O. castelnaui. A single male housed with 3−4 females is more suitable than a male housed with two females. Species’ temperaments vary considerably between the two extremes of ‘friendly’ and ‘very shy’. For example, the Marbled Velvet Gecko O. marmorata and the Southern Spotted Velvet Gecko O. tryoni are generally more outgoing than the Robust Velvet Gecko N. robusta. The Fringe-toed Velvet Gecko O. filicipoda is the most sensitive species and resents handling, loud noises, other geckos and excessive amounts of food in the enclosure. This species may sulk if food items crawl on them. page 306

FEEDING In the wild, velvet geckos feed on small spiders, cockroaches, crickets, moths and any other athropods. They feed by chasing down food items spotted from a distance, but will also sit and wait to ambush food items. In captivity, they will accept crickets, cockroaches, flies and moths. Insect food item size should measure approximately 60% of an individual’s head size. Food items should be lightly dusted with a suitable calcium and vitamin D3 supplement in at least two out of three feeds. Adults should be fed every 4−7 days in summer and every 7−10 days in winter, although they may not accept food for short periods during this time. Juveniles should be fed every 2−4 days throughout the year. In captivity, most young specimens prefer to hunt for food items in privacy. However, as they mature they become much more aggressive in their feeding responses. Some may take food offered directly from forceps, although this feeding method is not necessary. Occasionally, individuals within a pair or group may fight over food items, vocalising with loud squeals and squeaks, resulting in the food item being torn apart and one individual missing out and needing to hunt elsewhere. To prevent dominance during feeding, each individual should be supplied with 4−6 food items.

BREEDING In the wild, breeding occurs from September to March, although southern species including the Lesueur’s Velvet Gecko A. leseuerii and the Southern Spotted Velvet Gecko O. tryoni may commence breeding later in the season and finish earlier due to the cooler local weather conditions.  Species located in the north may breed from August to April. In captivity, breeding occurs from September to March. Out of season eggs are unusual. Small to medium-sized species are capable of reproduction when they reach 70% of adult SVL which may occur at 12−18 months of age. Larger species—including the Fringe-toed Velvet Gecko O. filicipoda and bulkier forms such as the Marbled Velvet Gecko O. marmorata from the far north of the range—often delay reproductive maturity until 24−36 months of age despite reaching adult size considerably sooner than this. Pair separation is not essential for breeding success and pairs and groups can be maintained together throughout the year. Out of season breeding is rare—females can rest in the off season in the presence of males. In fact, maintaining pairs together or pairing them up in the non-breeding season is preferable to reintroducing them during the breeding period, as some individuals may display territorial aggression towards a sudden trespasser. This reintroduction period is the only time I have ever witnessed severe injuries inflicted by velvet geckos. If a breeding season introduction is required it should occur on neutral ground or the male should be introduced to the female and not vice versa. Cooling is not essential where changes in local ambient temperatures are sufficient. If cooling is practiced, it can be achieved by gradually reducing the number of heating hours and temperatures to 18oC−24oC by day and to 15oC−18oC by night. In temperate species, cooling can be achieved by simply switching off the heat source. Courtship involves the male sniffing the back and neck of the female while waving his tail. He will then pounce on the female, grabbing her by the skin of her neck with his jaws. It is generally quite abrupt. page 307

D BROWN

D BROWN

A comparison of size variation in velvet gecko eggs— Oedura marmorata (left) and Amalosia rhombifer

Mating is often secretive and usually heard more frequently than seen. During mating, the female often squeals. The first eggs can be expected six weeks after ambient daytime temperatures rise above 25oC. A gravid female can be identified by a marked increase in girth. The eggs will be visible as distinct shapes through Eggs are clearly visible through the abdominal skin of this Oedura castelnaui her abdominal wall. A typical clutch is two eggs, although on occasion only one may be laid. The eggs are ovalshaped and leathery-shelled. They are moist when first laid, which can cause the substrate to stick to them. In captivity, 3–4 clutches per season are generally laid but some females may produce up to five clutches in a single season. The interval between clutches is usually 4–8 weeks. In captivity, nest facilities are easy to provide. Velvet geckos will nest in any enclosed container of moist substrate approximately 1.5−2 SVL on all sides. Suitable substrate is a mixture of coir peat and sand at a ratio of 50:50, or just coir peat or sphagnum moss. It should be moist enough that it sticks together temporarily when squeezed, but not so wet that water runs out of it. Females usually lay right at the bottom of the container. In some areas, the Southern Spotted Velvet Gecko O. tryoni has been recorded nesting communally with up to 20 eggs in a single site—it is not clear if this represents a preferred behaviour or is simply due to a lack of suitable nesting sites.

INCUBATION AND HATCHLING DEVELOPMENT Once laid, eggs should be removed for artificial incubation. Incubation should be in a mixture of water and vermiculite at a ratio of 1:1 by weight or 1:10 by volume. Incubation is relatively simple and without problems in these species. Standard non-vented containers are suitable for all species. It can be useful to separate the eggs of different morphs of the same species, as hatchlings often appear more similar than the adults. Eggs should be incubated at temperatures of 28oC−30oC. There is some evidence to suggest that eggs incubated at temperatures up to 25oC produce more females, whereas eggs incubated at temperatures of 26oC−28oC produce more males. However, the gender ratios of hatchlings produced at temperatures above 29oC have not been adequately recorded—it is assumed more females will be produced as typical with Type Three TSD. Considerable egg expansion occurs during incubation with increases of up to 40% in width and 25% in length being typical. If non-vented incubation containers are used, egg sweating will precede hatching by 24 hours. page 308

BREEDING RECORDS FOR VELVET GECKO SPECIES Clutch Size

Interclutch Interval (Days)

Egg size (mm) (Mean or Range) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

O. castelnaui

2

38−45

19−22 x 9.5−11

72−86 (28oC)

38−42/60−64

O. coggeri

2

28−45

16.8−20 x 10.5

64−70 (28oC)

31.7−34.9 SVL

O. filicipoda

2

−

22.2−26 x 10−12.4

64−81 (28oC)

37−45 SVL

O. gemmata

2

21

−

60 (29oC)

37.5−41.5/ 60.5−65.8

O. gracilis

2

55

−

60−68 (29oC)

−

A. lesueurii

2

30−43

14.5−17.5 x 8

58−80 (28oC−30oC)

28−29/45−46

O. marmorata

2

21−39

22−28 x 9.8−11

69−97 (28oC)

35−38/55−58

O. monilis

2

28−39

19−22 x 8.3−12.3

63−68 (28oC) 72−76 (27oC)

26−38/53−63

N. robusta

2

31−45

17.5−19 x 10−11

63−66 (28oC)

30−41/58−73

A. rhombifer

2

−

−

54 (28oC)

27/48

O. tryoni

2

33−56

20−21.5 x 10.5−12

56−75 (28oC)

35−37/62−64

SPECIES

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small holding container furnished with a small hide—such as a toilet roll, section of egg carton or small length of bamboo—and a water bowl. Substrate is unnecessary as most of a hatchling's time is spent within the hide. A heat pad or cord may be used under part of the enclosure to provide an ambient temperature of 26oC−28oC. Food should be offered 24 hours after hatching. Initially, items should measure approximately 25−35% of the hatchling’s head size and be increased in size to 60% after two weeks. Suitable food items include small crickets, small cockroaches and slaters.

Hybridisation is not common in Australia as ample specimens are available for breeding. Overseas, the quality of the Southern Spotted Velvet Gecko O. tryoni and Ocellated Velvet Gecko O. monilis populations has significantly declined due to hybridisation between these species.

C TUCKER

HYBRIDISATION AND COLOUR VARIANTS

Amelanistic Oedura castelnaui

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G STEPHENSON

Comparison of double factor (left), normal (centre) and single factor hypomelanistic morph (right) Oedura castelnaui

Colour mutations in this group occur in wild populations and captive strains. Well-developed populations of amelanistic Northern Velvet Geckos O. castelnaui exist overseas. This is an autosomal recessive mutation. Moderate numbers of hypomelanistic Northern Velvet Geckos O. castelnaui forms exist in Australia and this naturally occurring mutation can be found in the wild between Mount Carbine and Lakeland Downs in north Queensland. This mutation is codominant in its mode of inheritance, which explains the prevalence of partial hypomelanistic individuals (single factor codominant) compared to true hypomelanistic forms (double factor codominant). I have seen photographs of hypomelanistic Marbled Velvet Geckos O. marmorata in overseas collections, however I am unaware if these forms occur in Australia. An amelanistic Southern Spotted Velvet Gecko O. tryoni, bright yellow with white spots, was once produced by a colleague, however it died during hatching and the parents never produced another. page 310

D PEICA

Spotted Amalosia lesueurii morph

The Lesueur’s Velvet Gecko A. lesueurii has been bred in a ‘spotted’ form, which lacks the usual reticulated patterning. The naming of locality variants causes considerable confusion. There is considerable geographic variation in colour in some species. Many spectacular forms have been recorded according to their locality or been given fancy descriptive names. Subsequently, names such as Fat Tailed Marmorata have been erroneously and confusingly applied to Marbled Velvet Geckos O. marmorata that originate from the north of the Northern Territory—‘Top End’ marmorata is more suitable, as these are not currently considered as a different species but as specimens from the locality of the type specimens. Where possible, specific locality names should be used where they are known—for example, O. marmorata Alice Springs locale—otherwise they should be referred to according to their broader locale characteristics—for example, O. marmorata western Queensland locale.

LONGEVITY Velvet geckos live long lives. The average life span is 10−12 years with a productive period of 6−8 years. Some exceptional specimens maintained overseas live to more than 25 years of age.

ACKNOWLEDGEMENTS I would like to thank Grant Husband, Rob Porter, Dr Gavin Bedford, David Peica and Neil Sonnemann, among others, for their assistance with this chapter.

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J VOS

Delma grayii

PYGOPODS—FLAP FOOTED LIZARDS

S EIPPER

The pygopod group represented in captivity comprise four genera and at least 28 species—21 Delma species, five Pygopus species, one Paradelma species and one Lialis species including— Common Scaly-foot Pygopus lepidopodus Western Hooded Scaly-foot Pygopus nigriceps Eastern Hooded Scaly-foot Pygopus schraderi Northern Hooded Scaly-foot Pygopus steelescotti Marble-faced Delma Delma australis Rusty-Topped Delma Delma borea Patternless Delma Delma inornata Sharp-snouted Delma Delma nasuta Leaden Delma Delma plebeia Excitable Delma Delma tincta Burton’s Legless Lizard or Burtons Snake-lizard Lialis burtonis Brigalow Scaly-foot Paradelma orientalis

Delma australis

page 312

PRONUNCIATION

J VOS

Following are the accepted pronunciations of the most common members of the pygopod species. Pygopus lepidopodus Pie-go-pus lep-id-oh-poh-dus Pygopus nigriceps Pie-go-pus nig-ree-seps Pygopus schraderi Pie-go-pus sh-ray-der-ee Pygopus steelescotti Pie-go-pus steel-scott-ee Delma australis Dell-mah os-trah-liss Delma borea Dell-mah boar-ay-ah Delma inornata Dell-mah in-or-nah-tah Delma nasuta Dell-mah naz-ute-ah Delma plebeia Dell-mah pleb-ee-ah Delma tincta Dell-mah tink-tah Lialis burtonis Lie-ah-liss burr-toe-nee Paradelma orientalis Par-ah-dell-mah orr-ee-ent-ah-lis

S MACDONALD

Pygopus lepidopodus

Pygopus nigriceps

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J VOS D BROWN

Pygopus nigriceps

Pygopus schraderi

page 314

G STEPHENSON J VAN DEN BERGH

Pygopus schraderi

Pygopus lepidopodus

page 315

R JACKSON S MACDONALD

Pygopus schraderi

Paradelma orientalis

page 316

G GAIKHORST S EIPPER

Delma nasuta

Delma plebeia

page 317

G SCHMIDA S MACDONALD

Lialis burtonis

Lialis burtonis

page 318

S MACDONALD J VOS

Lialis burtonis

G SCHMIDA

Delma tincta

Lialis burtonis

page 319

S MACDONALD

Pygopus steelescotti

ADULTS

Features of a typical pygopod include J VAN DEN BERGH

DESCRIPTION

Flap foot

page 320

S EIPPER

S EIPPER

Pygopods are of small to medium size with long and slender bodies, no forelimbs and hind limb remnants that appear as small, scaly flaps. Although they resemble snakes, pygopods are most closely related to geckos and share several unique features not found in snakes—including the ability to vocalise and lick their eyelids, the presence of visible ear openings and broad, fleshy tongues. Broad fleshy tongue

Visible ear opening

S EIPPER S EIPPER

Elongated, wedged-shaped head and vertical slit pupils are unique features of Lialis burtonis

M ANTHONY

Juvenile snakes of the family Pseudonaja possess ‘warning bands’ across the head and neck. Pseudonaja textilis

Delma borea—many pygopods possess similar head markings S MACDONALD

They range in size—the smallest species Delma torquata measures 63mm SVL and the largest species the Burton’s Legless Lizard L. burtonis measures 290mm SVL. The majority of species in this group measure 90−200mm SVL. It is important to note that SVL represents as little as 20% of the body length in some species. A typical small Delma specimen measuring an average length of 110mm SVL will weigh an average of six grams. A larger specimen such as the Burton’s Legless Lizard L. burtonis measuring an average length of 210mm SVL will weigh an average of 12−13 grams. Delma, Pygopus species and the Brigalow Scaly-foot P. orientalis are similar in appearance with short bodies, moderately blunt heads and long, original tails, usually 2–4 times the length of their SVL. The Burton’s Legless Lizard L. burtonis is distinctly different with an elongated, wedge-shaped head, vertically slit pupils, a long body and a shorter tail—an original tail is usually less than 1.7 times the length of the body. Colouration varies according to species. Delma species are generally brown, tan or green in colour with complex markings on the head and body. Pygopus species are commonly brown, red-brown or grey in colour and may have distinctive patterning on the body. Brigalow Scaly-foot Pygopods P. orientalis are plain grey-brown in colour with a paler neck band. During their evolution, many pygopod species have developed a ‘warning band’ across their heads and necks. This is an example of Batesian mimicry, where a harmless animal takes on characteristics to appear harmful. In this case, the head markings of pygopods are an apparent Batesian mimicry of the warning markings on Pygopus schraderi—puffed out throat, extended neck and mock strikes are further used to deceive a predator

page 321

the head and neck of juvenile brown snakes Pseudonaja spp.. In some species it is present only on juveniles, fading as they age, whereas in others it is retained throughout life. Additionally, many pygopods will extend the mimicry to posturing as a venomous snake—some will take mock strikes, although they possess no ability to produce venom. The Burton’s Legless Lizard L. burtonis varies in colouration and patterning greatly—ranging from grey and brown to vivid yellow and orange. Some may have facial stripes and others may have fine stripes running lengthwise along the body.

JUVENILES

S MACDONALD

G GAIKHORST

Hatchlings are similar in appearance to the adult, but display brighter focal markings, such as the head markings typical of Delma species. They are generally 35−45% of average adult size and achieve adult proportions at 2−3 years of age.

Hatchling Delma plebeia

Hatchling Pygopus lepidopodus

SEXING Pygopods are moderately easy to visually sex as adults. Male Pygopus possess larger foot flaps than females, measuring the same length as the equivalent width at the same point of the body. In females the foot flap length is equivalent to two-thirds the width at the same point of the body. Prior to 1998, sexing a pygopod was achieved through guesswork or by using radiology to visualise post cloacal bones. In 1998, Rauhala and Andrew discovered the presence of small cloacal spurs under the hind limb flaps of a male Delma impar. This method has since been used successfully to sex other Delma, Pygopus, Brigalow Scaly-foot P. orientalis, and Burton’s Legless Lizard L. burtonis specimens. The spur is claw-like in most species, but flatter and more triangular in the Burton’s Legless Lizard L. burtonis. It is not known at precisely what age it develops—I have observed it in a Patternless Delma D. inornata of approximately 60% of adult size. The greatest difficulty when visually sexing a pygopod is holding it still to examine the cloacal spur. I recommend supporting the specimen’s body with a firm but gentle grip in front of and behind the cloaca. This will reduce the tendency for the pygopod to try twisting itself around as if in a crocodile roll. Small Delma species can be very strong and, despite their apparent attempt to ‘tear themselves apart’, I am yet to see a specimen autotomise its tail during this procedure. To inspect the cloacal spur, use a small, pointed but blunt implement, such as a sharpened pencil with the fine tip worn down, or a thin knitting needle. Lift the flap gently and look for the spur where the ventral part of the limb meets the body. It should be quite large and shiny in page 322

ANON ANON

ANON

Female Pygopus nigriceps with an absence of spur structures

ANON

Cloacal spur in a male Pygopus nigriceps

Cloacal spur in a male Delma inornata

Cloacal spur in a male Paradelma orientalis

ANON

Pygopus species and can be seen with minimal manipulation. When inspecting other species, patience and magnification is required. The cloacal spur is positioned much further back in the Brigalow Scaly-foot P. orientalis than in other species. In females the spur is usually absent, but if present it is less than one-third the size of that in a male. Preanal pores are present in Pygopus species. In males they are more discretely defined, with a large pore sitting centrally in a supporting scale—called a ‘perforate’ scale. The scales in the row immediately caudal to the ‘perforate’ scales are square and block-shaped and Pointed cloacal spur in Lialis burtonis comprise a row of 8−11 scales. In females the pore is significantly smaller and may appear as a small hole in the caudal edge of the supporting scale. The scales immediately caudal to the ‘perforate’ scales are triangular or rhomboid in shape and comprise a row of 5−7 scales. page 323

ANON

ANON

Ventral view of a male Pygopus nigriceps showing central preanal pores, longer foot flap length and eight scales caudal to the ‘imperforate’ scales

Ventral view of a female Pygopus nigriceps showing marginal preanal pores, shorter foot flap length and six scales caudal to the ‘imperforate’ scales

Hemipenal transillumination is unreliable in these species due to technical difficulties in performing the technique and the nature of the overlapping scales.

SUBSPECIES

D BROWN

Only one species within this diverse group has recognised subspecies—Delma concinna. The dorsal striping of each subspecies differs in appearance. The P. nigriceps complex was once considered to comprise of three subspecies—P. nigriceps nigriceps, P. nigriceps schraderi, and P. nigriceps steelescotti. These have since been given full species status and are named Pygopus nigriceps, Pygopus schraderi and Pygopus steelescotti. The Eastern Hooded Scaly-foot P. schraderi and the Northern Hooded Scaly-foot P. steelescotti are quite similar to the untrained eye but are readily distinguished by the absence of any form of darkening through the nostril in the Northern Hooded Scaly-foot P. steelescotti versus a full band or dark nostril in the Eastern Hooded Scaly-foot P. schraderi. The Common Scaly-foot P. lepidopodus was once recognised as a single species. However, northern Queensland populations are now recognised as a separate species Pygopus robertsi (Oliver et al 2010).

Head comparison of Pygopus steelescotti (above) and Pygopus schraderi. Note the absence of a nostril marking in the Pygopus steelescotti

page 324

IN THE WILD DISTRIBUTION AND HABITAT  

S MACDONALD

Pygopods are mostly endemic to Australia and can be found throughout the country, except in south-eastern Victoria and Tasmania. A handful of species can be found in New Guinea. Habitat is primarily grasslands where they may be found within dense grass tussocks, shrubby woodland or under fallen debris.

S EIPPER

J VOS

Mitchell’s grass and Brigalow habitat of Delma plebeia, Paradelma orientalis, Pygopus lepidopodus, Pygopus schraderi and Lialis burtonis, Glenmorgan, Queensland

Tropical open savannah habitat of Lialis burtonis, Delma tincta and Pygopus schraderi, Belyando Crossing, Queensland

Habitat of Lialis burtonis, Delma grayii, Delma fraseri and Pygopus lepidopodus, Jandakot, Western Australia

page 325

J VOS

Nests of stick-ants make ideal microhabitats for Delma species

Some Delma species are restricted to particular forms of coastal heathland in the south-western region of Western Australia. In this region Delma species may often be found in the piles of debris created by stick-ants Iridomyrmex conifer. The Burton’s Legless Lizard L. burtonis has a large range and inhabits grasslands in habitats ranging from central deserts to coastal heaths and rainforest margins, demonstrating its adaptability to varying conditions.

IN CAPTIVITY STATUS

S MACDONALD

Pygopods are highly sought after in captivity but are rarely available due to their unpredictable breeding performance. The most popular species are the Burton’s Legless Lizard L. burtonis and the Pygopus species. Delma species and the Brigalow Scaly-foot P. orientalis are rare in captivity. Other species of Australian pygopods are not represented in captivity.

Pygopus lepidopodus

page 326

S EIPPER S MACDONALD

Paradelma orientalis

Delma inornata

page 327

G SCHMIDA

Pygopus schraderi

HOUSING Pygopods are easy to maintain in captivity and require conditions similar to that of skinks.

INDOOR ENCLOSURES Suitable enclosures include plastic and commercial terrariums, fish tanks and plastic tubs. These should measure a minimum of 3−6 SVL long x 3−6 SVL wide x 3−5 SVL high for pairs of larger species or groups of smaller species. The appropriate height depends on the furnishings within. Suitable substrate is sand, as these species generally congregate under the substrate when cooled and move into vertical furnishings when active and heated. The Common Scaly-foot P. lepidopodus has been recorded as digging its own burrows using a unique method of grabbing the moist substrate with its mouth and ‘crocodile rolling’ to dislodge pieces and carrying this loosened soil out of the burrow to deposit it outside. It then rolls in the burrow to presumably widen it. Provide furnishings of flat pieces of bark, terracotta saucers and dry grass clumps—any stiff grass that holds its shape when dead is suitable. Multiple hides can be provided, although Delma species, which will tolerate living at higher densities than other species, will invariably congregate in groups despite separate hides sites being available. This ‘social’ behavior may be supported in the wild by the regular observation of mass sloughing areas, suggesting large numbers of specimens congregating in a single appropriate area. Pygopods often bask secretively. They prefer to bask on top of loose vegetation or under a thin layer of surface leaf litter or bark slabs. They expose only parts of their bodies when basking and will retreat quickly when approached. Often several specimens will bask together in a tangled ball—particularly Delma species. A basking temperature of 35oC−40oC with an enclosure temperature of 28oC−30oC in the remainder of the enclosure is ideal. page 328

D BROWN

Small halogen bulbs and small reflector globes directed either onto stiff grass clumps or a flat piece of bark on the floor are suitable for heating. Heat must be provided for at least 14 hours daily during summer and for a couple of hours daily during winter. Heating time can gradually be reduced from mid-autumn by 30–60 minutes each week. This heating regimen enables the occupants to bask if they need, and spend most of the day in ambient winter conditions. Reverse these heating levels by increasing the time heat is provided from early spring to return the enclosure to summer conditions. In environments similar to that of their natural origin, the heating may be turned off in winter and visible light utilised to mimic the photoperiod. Active cooling during winter is only considered necessary for breeding pygopods. Juveniles do not need to Components of a suitable enclosure be cooled during winter and should be maintained at full temperature to allow for continued feeding and growth throughout the year. The provision of UV-B light is not essential for these species. UV-B lamps of 5% UV-B are ideal. They may not be required if adequate calcium and vitamin D3 is provided through the diet.

Summary A basic enclosure for pygopods should include the following— • Substrate of sand. • Stiff upright grass clumps, fine branches, leaf litter and bark slabs placed on the floor. • Small halogens or reflector globes directed onto grass clumps or surface hides and providing a basking temperature of 35oC−40oC and an enclosure heat gradient of 26oC−28oC. • A nestbox. • A water bowl.

OUTDOOR ENCLOSURES Pygopods are ideally suited to outdoor housing and report best breeding results when maintained outside, particularly Delma species. The main disadvantage of housing these species outdoors is that, because of their cryptic nature, the only clue to their existence may be the nameplate on their cage. Suitable enclosures include commercial mesh terrariums, large plastic tubs and suspended or traditional aviaries for large species. Fine mesh, such as shadecloth or aluminium flyscreen, is necessary for security reasons in enclosures housing small species such as Delma. Placing 6mm wire mesh over this will prevent invasion by mice. page 329

S MACDONALD G STEPHENSON

Pygopus steelescotti

Pygopus schraderi

page 330

D BROWN

COMPATIBILITY

Pygopods vary in temperament. Generally, most species can be housed in pairs or small groups—I have maintained Delma in groups of seven with no problems. Delma will often aggregate under single hide sites. Some Pygopus specimens are exceedingly aggressive and may need to be housed separately outside of the breeding period. The provision of additional hide sites may reduce aggression, however the persecuted individual will usually have difficulty feeding and will benefit from separation, even on a temporary basis. Some breeders maintain Pygopus separately for Delma plebeia aggregation under a bark hide most of the year and only introduce them for breeding. It is often the female that is the primary aggressor. When keeping Delma species, be prepared for their escape strategy called ‘flick leaping’, which can be very effective. It involves them leaping into the air with a rapid twist of the body several times in quick succession. Individuals can quickly ‘flick’ themselves out of enclosure doors without being noticed.

FEEDING In the wild, pygopods feed on small insects including termites, spiders, slaters and cockroaches. In captivity, most species—except the Burton’s Legless Lizard L. burtonis—will accept any small insect offered including spiders, roaches, moths, slaters and termites. I have noted a distinct preference for crickets over other insects, however it can depend on what they are accustomed to eating. Some Pygopus individuals will consume soft, fruit-based baby foods or lorikeet nectar—this is a good feeding option for an injured specimen, as I experienced when an individual was injured by a female partner and required assist feeding. It should be supplied as a mix comprising baby food and parrot hand rearing mix or Wombaroo™ insectivore mix. Larger species may accept banana or pawpaw. Common Scaly-foots P. lepidopodus prefer to feed on spiders as a natural diet but will readily accept other insects in captivity. They have also been known to consume skinks, frogs and the tails of other scaly foot lizards acquired while fighting. The Leaden Delma D. plebeia has been observed eating lizards on occasion—I have seen them catch and consume Cryptoblepharus pulcher skinks temporarily housed with them. Some specialised pygopods consume ant eggs, pupae and, at times, adult ants which are taken directly from the centre of the nest and swallowed whole. Brigalow Scaly-foots P. orientalis are fond of small spiders and, once they catch the scent, will greedily take them from a keeper’s fingers or forceps. page 331

S MACDONALD

D BROWN

Paradelma orientalis will often spend an hour or more licking the surface of the Acacia sap balls

This species also readily consumes Acacia sap and will lick dried sap balls as if they are a toffee apple as well as swallowing any pieces it can dislodge by grasping an edge of the sap ball and twisting. Unlike most saps, Acacia sap is water soluble, and placing the sap ball in a glass of water for five minutes before feeding softens the outer layer and makes feeding easier. Sourcing Acacia sap can be difficult—it can usually be Sap flow in an Acacia in an area frequented by found oozing from the bark of an Acacia tree at Paradelma orientalis a point of stress, such as in a crack in the bark or where heavy branches are hanging. Some Acacia species will ooze sap from the entire trunk. Wounding a garden specimen to encourage sap flow is another option. The Burton’s Legless Lizard L. burtonis and Pygopus species may accept small fish, such as Gambusia or guppies. Food item size should measure up to the size of an individual’s head. Pygopods will often target surprisingly large food items, often subduing the prey with twists and ‘crocodile rolls’. Larger items may be consumed one piece at a time or the abdominal contents may be lapped up first. Food items should be dusted with a suitable calcium and vitamin D3 supplement in at least two out of three feeds. Adults should be fed 1−2 times per week and juveniles 3−4 times per week until six months of age when they can be fed as adults. The Burton’s Legless Lizard L. burtonis is the only pygopod that is challenging to feed. It feeds naturally on live lizards—particularly skinks, and requires a diet of 1−2 average-sized (8−12cm TL) skinks per week to survive. In the wild, large specimens will consume small and large skinks and hatchling dragons. Small specimens will consume small skinks and small geckos. They generally feed at dawn and dusk—despite the diurnal nature of their prey. This may be due to the species’ tolerance to lower temperatures and a greater ease of catching slower cooled prey than fast active prey. Lialis burtonis usually stalk their prey, waiting in ambush or use the tip of their tail as a caudal lure to distract or attract the prey item. As the item nears, they will grab it mid-body and grip it around the mid-chest—effectively suffocating it with the pressure of their jaws. The lizard prey is then manipulated and swallowed head first. page 332

S MACDONALD

and in one piece…

until just the tail tip is visible D BROWN

S MACDONALD

S MACDONALD

so it can be swallowed head first…

S MACDONALD

This Lialis burtonis grabs the Lampropholis delicata skink mid-body and manipulates it in to a better position...

D BROWN

The supply of live lizards to replicate this feeding strategy is limited. Many state governments—despite allowing herpetologists to keep the Burton’s Legless Lizard L. burtonis in captivity—prohibit the collection and feeding of the lizards that it relies on to survive. It is a ridiculous situation that has prompted many herpetologists to seek alternative diets for their specimens— Lialis burtonis feeding on a pinkie mouse with varying degrees of success. Records of Lialis species taking insects invariably refer to Lialis jicari from New Guinea, which is less obsessive in its dietary preferences. Other species will accept frozen lizard items, which in turn reduce the parasitic intake, although I am yet to find a clinically important intestinal parasite in a Burton’s Legless Lizard L. burtonis specimen. Frozen skink tails or gecko tails may also be used. Feeding accidents occasionally occur with the Lialis burtonis. Both Lialis specimens in this photograph survived, however the skink did not

page 333

The ultimate goal is to get a Burton’s Legless Lizard L. burtonis specimen to actively consume food other than lizards. My attempts to achieve this have only succeeded when I have used assist feeding—placing the food item in the mouth of the lizard. Mouse tails are suitable for assist feeding, however they may not provide adequate nutrition and may result in gut impaction or digestion problems if they are from old mice or rats. Some herpetologists have managed to convince Burton’s Legless Lizards L. burtonis to consume pinkie mice. This is a slow process but can be achieved by scenting the mice with crushed skink tails, skink blood or skink urine. The scent will gradually render the pinkie mouse a tolerated food item and eventually result in the skink accepting the shape of the pinkie mouse as a feeding cue. It is a process that requires a lot of patience and is not always successful. Alternatively, you may place a skink tail inside the mouth of a pinkie mouse to create a combination scent that may trick some individuals. Feeding accidents involving the Burton’s Legless Lizard L. burtonis occur on occasion— particularly if two specimens grab the same skink. They should be supervised or separated at feeding time.

BREEDING In the wild, breeding occurs from August to March. Little else is known about the breeding habits of pygopods due to the difficulties associated with breeding them in captivity. Many successful breeding outcomes have been the result of happy accidents as much as any particular method or approach. A number of breeding successes and their related data are the result of gravid wild caught individuals being held in captivity until their eggs are laid and subsequently incubated and hatched. Breeding size has only been recorded for Delma species. Delma impar and D. torquata individuals are capable of reproduction when they reach 70% of adult SVL which may occur at 2−3 years of age. Separation may enhance breeding success. Positive breeding outcomes with the Eastern Hooded Scaly-foot P. schraderi and the Common Scaly-foot P. lepidopodus have resulted from managing them in a manner similar to a breeding python—maintaining them separately and introducing the males for short periods during winter/spring. This can be repeated weekly throughout this period and following egg laying. Pair compatibility does not necessarily lead to breeding success. Several seasons of unsuccessful breeding with a female Common Scaly-foot P. lepidopodus warranted a mate exchange. This new mate fought vigorously with the female and was removed after a few weeks—yet the female still produced a successful clutch. The male was returned to the enclosure post egg laying, which resulted in similar behaviour but yet another successful breeding outcome and the production of two more clutches. It is not certain if the combat between the male and female had any bearing on this success. Research involving D. impar found the chances of breeding are enhanced if— • Feeding is increased prior to cooling—this reduces the effects of weight loss in the winter period. • A friable, bed of nesting substrate 10−20cm deep is supplied to allow burrows to be dug and depressions to be made for eggs. • The animals are exposed to natural climatic conditions rather than constant temperatures. Few courtship or mating displays have been observed. Cook (2009) observed courtship and mating of the Eastern Hooded Scaly-foot P. schraderi, which involved the male flicking his tongue repeatedly while following the female around the enclosure. When the female stopped moving, page 334

D BROWN

D BROWN

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Gravid Lialis burtonis with eggs visible through her ventral abdomen

Gravid Pygopus lepidopodus displaying caudal abdominal swelling

Gravid Delma plebeia displaying subtle caudal abdominal swelling

the male sidled up to her, biting her near the base of her tail. He then let go and bit her further up the body towards the midsection. Letting go once more, he again bit her below the nape. While biting her he erected his paddle-like hind limbs perpendicular to his body, eventually grasping her with them. Mating lasted approximately two minutes. Mating is generally initiated within four weeks of enclosure temperatures rising above 26oC and basking temperatures rising above 29oC. The first eggs can be expected 4−6 weeks after mating. A gravid female can be identified by a marked increase in girth. The eggs may be visible through her abdominal wall or may just appear as a diffuse caudal swelling. A typical clutch for most species in this group is two eggs, however on occasion only one may be laid. The eggs are oval-shaped and leathery-shelled. They are moist when first laid, which can cause the substrate to stick to them. In the wild, it is presumed that, like geckos, 1−3 clutches are laid each year. In captivity, females provided with adequate nutrition may produce as many as four clutches per year. The interval between clutches has been recorded as approximately one month in the Eastern Hooded Scaly-foot P. schraderi and the Common Scaly-foot P. lepidopodus. In the wild, females nest in soft soil or in soil under stone slabs. The Burton’s Legless Lizard L. burtonis and Pygopus species have been recorded nesting communally in the wild—it is not clear if this is due to a lack of suitable nesting sites, multiple females nesting together or a single female returning to the same nest site on more than one occasion. In captivity, nest facilities are easy to provide. Females will nest in any area of moist substrate, in nest boxes containing moist sand or peat moss, under bark slabs or on moist peat moss. The most successful captive breeding outcomes—particularly with smaller species—have occurred in naturalistic outdoor enclosures with a substrate of sand or peat mix 15−20cm deep. Eggs are deposited in the substrate at varying depths and the female may enter the nest for a number of days before laying her eggs. Cook (2009) notes that Eastern Hooded Scaly-foot P. schraderi females consistently shed their skin 5−6 days before egg laying. This has also been recorded in the Burton’s Legless Lizard L. burtonis. Whether this truly has parallels to the ‘pre-lay shed’ of pythons is unknown. page 335

H COOK

D BROWN

Pygopus schraderi hatchlings

Pygopus lepidopodus hatchling and egg

INCUBATION AND HATCHLING DEVELOPMENT Once laid, eggs should be removed for artificial incubation. Incubation should be in a mixture of water and vermiculite at a ratio of 1:1 by weight or 1:10 by volume. Considerable egg expansion occurs during incubation with the eggs becoming rounder as incubation progresses. If non-vented incubation containers are used, egg sweating will precede hatching by 24 hours.

BREEDING RECORDS FOR PYGOPOD SPECIES SPECIES

Egg size (mm) Clutch Interclutch Interval (Mean or Range) Size (Days) (Length x Width)

Incubation Period (Days) at the specified temperature

Hatchling SVL/TL mm

D. australis

2

−

13−16 x 4−5

66 (28oC)

31 SVL

D. butleri

2

−

19−20 x 8

−

−

D. fraseri

2

−

22−23 x 7−8

74−77 (28oC)

45−46 SVL

D. grayii

2

−

26.5−29 x 10

61−62 (30oC)

D. impar

1−2

−

18−23 x 8−9

38−50 (25 C−31 C)

32−41/80−115

D. tincta

2

−

13.5−13.8 x 6−6.6

−

−

D. torquata

2

−

12.8 x 5.9

−

−

D. inornata

2

−

26−29 x 9−10

−

−

L. burtonis

2

−

21−24 x 9−11

63−71 (28oC−29oC)

63−78/138−153

P. nigriceps

2

−

18−18.5 x 12−13

73−74 (30oC)

72−76 SVL

P. schraderi

2

29.5

27.2−31.9 x 11.4−13.2

64 (30oC)

80 TL

P. lepidopodus

2

28−32

38−46 x 16−21

68−85 (28oC−30oC)

85−90/160−250

o

44/150 o

Hatchlings should remain in the incubation container for 24 hours after hatching and then be moved to a small holding container furnished with a small hide—such as a half toilet roll or upturned terracotta saucer—and a water bowl. page 336

HYBRIDISATION AND COLOUR VARIANTS

J VOS

Moist substrate should be provided under a hide or in a small plastic tub as these hatchlings are prone to dehydration. A head cord or mat should be placed under part of the enclosure to provide a basking temperature of 26oC−28oC. Food should be offered within 3−7 days of hatching. Initially, items should measure approximately 25−35% of the hatchling’s head size and be increased in size to 50% by four months of age. Suitable food items include termites and pinhead crickets for hatchling Delma species and cockroaches and crickets for hatchling Pygopus species. Burton’s Legless Lizard L. burtonis hatchlings may initially be fed hatchling skinks if available, larger skink tails, or they may be assist fed fuzzie mice hind limbs or tails.

G SCHMIDA

Hybridisation and colour variants have not been recorded in these species. Most species—except the Burton’s Legless Lizard L. burtonis—are constant in their colour and pattern. There are some very attractive variations within populations. Some populations of the Common Scaly-foot P. lepidopodus are a ‘heathland’ colour form, which is an attractive patterned ‘Heathland’ form Pygopus lepidopodus silver. Strangely, a similar colour morph occurs in the Eastern Hooded Scalyfoot P. schraderi but in association with blacksoil and Mitchell grass plains around Winton and Longreach, Queensland. Burton’s Legless Lizards L. burtonis are found in every conceivable colour and pattern. Unfortunately, attempts to breed from spectacularly coloured individuals have proved frustrating, as there are no clear patterns of inheritance.

LONGEVITY

‘Blacksoil’ form Pygopus schraderi

Pygopods live moderately long lives. Although longevity records for this group are sparse, the average lifespan of smaller species is 6−8 years with a productive period of 5−6 years. The average life span of larger species is more than 12 years with a productive period of approximately eight years.

ACKNOWLEDGEMENTS I would like to thank Rob Porter, Henry Cook, Nathan Clout and Gary Stokes, among others, for their assistance with this chapter. page 337

AUSTRALIAN HERPETOLOGICAL SOCIETIES AND USEFUL WEBSITES HERPETOLOGICAL SOCIETIES NEW SOUTH WALES

QUEENSLAND

http://www.ahs.org.au/index.php

http://web.mac.com/breadnbutterdesign/HSQ/ HSQ.html

Australian Herpetelogical Society Inc. Meets the fourth Wednesday of every month, except December Hawkesbury Herpetological Society Meets the second Friday of every month at 7:30pm http://www.hawkesburyherps.com.au/

Illawarra Reptile Society Meets the first Monday of every month at 7pm

http://www.illawarrareptilesociety.com.au/

Herpetological Society of Queensland Incorporated Meets the first Sunday of every second month North Queensland Herpetological Society Meets the second Wednesday of every month at 7pm http://www.freewebs.com/nqherpetology/

SOUTH AUSTRALIA

Macarthur Herpetological Society PO Box 235, Narellan, NSW 2567 Meets the third Friday of every month, except in December North Coast Herpetological Group Meets the first Friday of every month at 7pm The Orana Herpetological Society Meets the third Saturday of every month

South Australian Herpetological Group Meets the second Tuesday of every month at 7.30pm

http://members.tripod.com/~snakyo/

Tasmanian Herpetological Society (THS) Meets the first Tuesday of every even month (e.g. Feb, Apr, June etc) at 7.30pm Email: [email protected]

VICTORIA

WESTERN AUSTRALIA

Victorian Association of Amateur Herpetologists Meets the last Friday every three months http://www.vaah.org.au/

Victorian Herpetological Society Meets four times per year

http://www.swiftpages.com/sahg/index.html

TASMANIA

West Australian Herpetological Society Incorporated Meets the first Friday of every month at 7pm http://www.wahs.org.au/

http://vhs.com.au/

OTHER USEFUL WEBSITES The following websites are those I have personally found useful for information, animals for sale and chat forums. Reptile Publications Australian Reptile Forum http://www.reptilepublications.com http://www.australianreptileforum.com/arf ABK Publications Herp Shop http://www.birdkeeper.com.au http://www.herpshop.com.au Aussie Pythons & Snakes Reptiles Down Under http://www.aussiepythons.com www.reptilesdownunder.com page 338

BIBLIOGRAPHY PRINTED LITERATURE Annable, T 1983, ‘Some observations on vocalisation and the use of limb flaps in the Pygopod lizard Delma inornata’, Herpetofauna, vol. 14 (2), pp. 80–82. Annable, T 1992, ‘Observations on the husbandry and captive breeding of Nephrurus asper, the spiny knob-tailed gecko’, Herpetofauna, vol. 22 (1), pp. 7–11. Banks, C, Hawkes, T, Birkett, J, and Vincent M 1999, ‘Captive management and breeding of the Striped Legless Lizard Delma impar at Melbourne Zoo’, Herpetofauna, vol. 29 (2), pp. 19–29. Barnett, B 1979, ‘Incubation of sand goanna eggs’, Herpetofauna, vol. 11 (1), pp. 21–22. Bauer, AM & Doughty, P 2012, 'A new bent-toed gecko (Squamata: Gekkonidae: Cyrtodactylus) from the Kimberley region, Western Australia', Zootaxa, 3187, pp. 32-42. Brown, D, Worthington Wilmer, J, Macdonald, S, 2012, ‘A revision of Strophurus taenicauda (Squamata; Diplodactylidae) with the description of two new subspecies from central Queensland and a southerly range extension’, Zootaxa , 3243: 1–28 Bush, B 1983, ‘A record of reproduction in captive Delma australis and D. fraseri’, Herpetofauna, vol. 15 (1), pp. 11–12. Bush, B, Maryan, B, Browne-Cooper, R & Robinson, D 2007, Reptiles and frogs in the bush: southwestern Australia, University of Western Australia Press, Crawley, Western Australia. Cogger, HG 1983, Reptiles and Amphibians of Australia, 3rd edn, rev., Reed New Holland, Sydney, New South Wales. Cogger, HG 1993, Reptiles and Amphibians of Australia, Reed New Holland, Sydney, New South Wales. Comber, S 2000, ‘The thick-tailed gecko in captivity’, Monitor, vol. 11 (1), pp. 9–12. Cook, H 2009, ‘A first for pygopods’, Reptiles Australia, vol 5. (2), pp. 48. Crews, D 1994, ‘Temperature, steroids and sex determination’, Journal of Endocrinology, vol. 142, pp. 1–8. Daly, G 1992, ‘Reproductive biology of the scalyfoot Pygopus lepidopodus’, Herpetofauna, vol. 22 (2), pp. 40–41. Davis, AR & Leavitt, DH 2007, ‘Candlelight vigilis: A non-invasive method for sexing small, sexually monomorphic lizards’, Herpetological Review, vol. 38 (4), pp. 402–404. Delean, S & Harvey, C 1981, ‘Some observations on the knob-tailed gecko Nephrurus laevissimus in the wild’, Herpetofauna, vol. 13 (1). de Vosjoli, P 1994, The lizard keepers handbook, American Federation of Herpetologists, California. de Vosjoli, P 1997, ‘How to establish the ring-tailed bent toed gecko Cyrtodactylus louisiadensis’, The Vivarium, vol. 7 (4), pp. 18–21. Dierenfeld, ES 2003, Herbivore Insect Composition, EAZA News. Doughty, P & Oliver, PM 2011, ‘A new species of Underwoodisaurus (squamata: gekkota: carphodactylidae) from the Pilbara region of Western Australia’, Zootaxa, 3010, pp. 20–30. Ehmann, H 1980, ‘Diurnal perching by the southern spiny-tailed gecko’, Herpetofauna, vol. 12 (1), pp. 37. Ehmann, H 1992, Encyclopedia of Australian animals—reptiles, The National Photographic Index of Australian Wildlife, Angus and Robertson, Sydney, New South Wales. Fitzgerald, M 1983, ‘Some observations on the reproductive biology of the Common Scaly-foot Pygopus lepidopodus’, Herpetofauna, vol. 14 (2), pp. 79–80. Fyfe, G 1991, ‘Possible ‘double clutching’ in Strophurus ciliaris’, Herpetofauna, vol. 21 (2), pp. 28. Greer, AE 1989, The biology and evolution of Australian lizards, Surrey Beatty & Sons, Sydney, New South Wales, pp. 264. page 339

Henkel, FW & Schmidt, W 2003, Professional breeders series—geckos, Chimaira Frankfurt Main, Germany. Husband, G 1980, ‘Unusual burrowing behaviour in Pygopus lepidopodus’, Herpetofauna, vol. 12 (1), pp. 36. International Air Transport Association 2005, Live animal regulations—container requirement 41, pp. 271–276. Kraus, F 2007, ‘A new species of Cyrtodactylus (Squamata: Gekkonidae) from western Papua New Guinea’, Zootaxa, 1425, pp. 63–68. Kraus, F & Allison, A 2006, ‘A new species of Cyrtodactylus (Lacertilia: Gekkonidae) from Papua New Guinea’, Zootaxa, 1247, pp. 59–68. Kraus, F 2008, ‘Taxonomic partitioning of Cyrtodactylus louisiadensis (Lacertilia: Gekkonidae) from Papua New Guinea’, Zootaxa,1883, pp. 1–27. Laube, A 1993, ‘Diplodactylus williamsi’, Sauria, Suppl., vol. 15 (1–4), pp. 273–276. Laube, A 1994, ‘Oedura castelnaui’, Sauria, Suppl., vol. 16 (3), pp. 297–302. Laube, A 1997, ‘Diplodactylus tesselatus’, Sauria, Suppl., vol. 19 (3), pp. 413–416. Laube, A 1998, ‘Strophurus spinigerus’, Sauria, Suppl., vol. 20 (3), pp. 435–440. Laube, A 1999, ‘Diplodactylus galeatus’, Sauria, Suppl., vol. 21 (1), pp. 29–32. Laube, A 2000, ‘Captive maintenance and breeding of some ground dwelling Australian geckos, part I, Nephrurus laevissimus and Nephrurus levis’, Gekko, vol. 2 (1), pp. 31–36. Laube, A 2000, ‘Captive maintenance and breeding of some ground dwelling Australian geckos, part II, Diplodactylus byrneii, Diplodactylus tesselatus, Diplodactylus steindachneri’, Gekko, vol. 2 (2), pp. 12–18. Laube, A 2002, ‘Captive maintenance and breeding of some ground dwelling Australian geckos, part III, Nephrurus amyae’, Gekko, vol. 3 (2), pp. 43–48. Laube, A & Porter, R 2004, ‘Captive maintenance and breeding of some ground dwelling Australian geckos, part IV, Underwoodisaurus milii and Underwoodisaurus sphyrurus’, Gekko, vol. 4 (1), pp. 23– 32. Laube, A 2007, ‘Nephrurus amyae’, Sauria, Suppl., vol. 29 (1), pp. 15–21. Maryan, B 1998, ‘Notes on reproduction in captive Delma grayii (Lacertilia: Pygopodidae)’, Herpetofauna, vol. 28 (2), pp. 47. McGrath, J 2007, ‘Under-wood-he-saw-us—the thick-tailed gecko’, Reptiles Australia, vol. 3 (4), pp. 8–17. Naylor, L 2000, ‘Predation of a northern Dtella (Gehyra australis) by a Ring-Tailed Gecko (Cyrtodactylus louisiadensis)’, Herpetofauna, vol. 30 (1), pp. 53. Oliver, PM, Adams, M, Lee, M, Hutchinson, M & Doughty, P 2009, ‘Cryptic diversity in vertebrates: molecular data double estimates of species diversity in a radiation of Australian lizards (Diplodactylus, Gekkota)’, Proceedings of the Royal Society B: Biological Sciences, published online 4 March 2009, rspb.royalsocietypublishing.org. Oliver, PM & Bauer, AM 2011, ‘Systematics and evolution of the Australian knob-tail geckos (Nephrurus, Carphodactylidae, Gekkota): Pleisomorphic grades and biome shifts through the Miocene’, Molecular Phylogenics and Evolution. Oliver, PM, Bauer, AM, Greenbaum, E, Jackman, T & Hobbie, T 2012, ‘Molecular phylogenetics of the arboreal Australian gecko genus Oedura gray 1842 (Gekkota: Diplodactylidae): another plesiomorphic grade?’, Molecular Phylogenetics and Evolution Oliver, PM, Cooper, P & Amey, A 2010, ‘A new species of Pygopus (Pygopodidae; Gekkota; Squamata) from north-eastern Queensland’, Zootaxa, 2578, vol. 47–61. Porter, R 1999, ‘Captive maintenance and breeding of Australian leaf-tail geckos (Saltuarius and Phyllurus)’, Herpetofauna, vol. 29 (2). page 340

Porter, R 2000 ‘The husbandry and first recorded captive breeding of the Chameleon Gecko’, Gekko, vol. 2 (2), pp. 2–8. Porter, R 2005, ‘Captive breeding and maintenance of rough knob-tailed geckos’, Reptiles Australia, vol. 2 (3), pp. 6–10. Porter, R 2006, ‘The captive husbandry and breeding of the sand swimmer’, Reptiles Australia, vol. 2 (6), pp. 17–23. Porter, R 2008, Keeping Australian geckos, Australian Reptile Keeper Publications, Adelaide, South Australia. Rauhala, MA & Andrew, W 1998, ‘External sexing of the Striped Legless Lizard Delma impar using cloacal spurs’, Internal Report 99/1, Environment ACT, Australian Capital Territory. Rösler, H, Richards, SJ & Günther, R 2007, ‘Remarks on morphology and taxonomy of geckos of the genus Cyrtodactylus Gray, 1827, occurring east of Wallacea, with descriptions of two new species (Reptilia: Sauria: Gekkonidae)’, Salamandra, vol. 43, pp.193–230. Rogner, M 1997, Lizards—volume 1 and 2, Krieger Publishing, Florida, United States of America. Shea, G, Couper, P, Worthington, W & Amey, A 2011, ‘Revision of the genus Cyrtodactylus gray 1827 (Squamata: Gekkonidae) in Australia’, Zootaxa, vol. 3146, pp. 1–63. Schmida, G 1985, The cold-blooded Australians, Doubleday, Sydney, New South Wales. Stow, A 1998, ‘Diurnal retreat sites for leaf-tailed geckos, Phyllurus platurus’, Herpetofauna, vol. 28 (2), pp. 25–29. Swan, M (editor) 2009, Keeping and breeding Australian lizards, Mike Swan Herp Books, Victoria. Tousignant, A & Crews, D 1994, ‘Effects of exogenous estradiol applied at different embryonic stages on sex determination, growth and mortality in the leopard gecko (Eublepharis macularius)’, Journal of Experimental Zoology, 268, pp. 17–21. Treseder, S 2008, ‘Hot wheels—captive husbandry of the banded knob-tailed gecko’, Reptiles Australia, vol. 4 (4), pp. 13–20. Trugden, T 2001 ‘Lialis burtonis’, Course Notes, James Cook University. Wells, RW & Wellington, CR 1985, ‘A clas­sification of the amphibia and reptilia of Australia’, Australian Journal of Herpetology, Suppl. vol. 1 (3–4), pp. 1–61. Wells, W 2002, ‘Taxonomic notes on the genus Cyrtodactylus (Reptilia: Gekkonidae) in Aus­tralia’ Australian Biodiversity Record, 2002 (3), pp. 1–8. Wells, RW & Wellington, CR 1984, ‘A syn­opsis of class Reptilia in Australia’, Australian Journal of Herpetology, vol. 1 (3–4), pp. 73–129. Wilson, S 2005, Field guide to reptiles of Queensland, Reed New Holland, Australia. Wilson, SK & Knowles, DG 1988, Australia’s reptiles, Harper Collins Publishers, Sydney, New South Wales.

ONLINE RESOURCES Barnett, B 2001, Speckled feeder roaches, http://www.herpshop.com.au/CareSheets/FeaderRoach. doc Chamowners Web 2008, Nutritional value of various insects, www.chamownersweb.net/insects/ nutritional_values.htm Kaplan, M 2009, Housing and feeding invertebrate prey, www.anapsid.org/feedingbugs.html Kaplan, M 2009, Nutrients of foods commonly fed to carnivorous and omnivorous reptiles, www.anapsid.org/resources/preynutrients.html page 341

GLOSSARY

Following is an explanation of some herpetological words used within this and other texts. Adhesive lamellae The finger-like projections on the fingers (and sometimes tail tips) of reptiles that aid in climbing. Agamid Dragon. Alates Flying termites or ants. Albino An individual devoid of pigment cells. Anasarcia A developmental abnormality in which a hatchling’s skin is distended with fluid. Anerythristic An individual devoid of red pigment cells. Anorexia A state of unwillingness to feed or a loss of appetite for food. Amelanistic An individual devoid of melanin (black) pigment cells. Aquatic Habitat in or near water. Arboreal Individuals that live predominantly above the ground i.e. in vegetation. Arthropod An animal with an external skeleton; predominantly refers to insects but also includes spiders and crustaceans. Autotomy The ability to spontaneously cast off all or part of a tail, usually as a defensive response. Axanthic An individual devoid of xanthophore (yellow) pigment cells. Basking The act of a lizard exposing itself to increased temperature in order to raise its core body temperature. page 342

Bipedally A behaviour in which a normally quadrupedal species stands or moves only on its two back legs. Brumate A behaviour akin to mammalian hibernation in which a lizard seeks out a secluded spot, ceases feeding and lowers its metabolic rate to wait out the cold winter period. Candling Using a cool bright light to visualise the inside of a reptile egg. Caudal At or near the back half of the body. Chevrons Triangular or arrow-shaped skin markings. Chitin The major component of the hard outer coating, or exoskeleton, of an arthropod. Cloaca The combined exit for gastrointestinal waste, kidney waste and reproductive products. Clutch The number of eggs laid by a female reptile in a single reproductive event. Co-dominant A genetic mutation in which both the normal and mutation state are equally expressed i.e. normal + mutant = intermediate form. Colour morph Any mutation that causes a visible change in appearance. Cooling The act of reducing enclosure temperature in order to stimulate brumation. Cranial At or near the front half of the body. Crepuscular Active at dawn and dusk.

Dewlaps Skin extension on the chins of some lizards, particularly dragons. Diploid An individual possessing two copies of the Z chromosome. This indicates a typical female reptile. Distal The outer part of a structure or limb; situated away from the centre of the body. Diurnal Active during daylight. Dominant Mutation A genetic mutation in which the phenotype is expressed the same in both the heterozygous and homozygous state. Double Factor Co-dominant An individual possessing two copies of mutant genes i.e. the mutant individual is visible in its complete form. Dorsal Of, on, or relating to the upper half or top of a structure or body. Dorsally Compressed Also called dorsoventrally flattened; flattened from top to bottom. Dusting The act of coating an insect food with a calcium or vitamin supplement. Dysecdysis A situation in which a skin shed is not able to be carried out normally. Dystocia Also known as egg-binding or post-ovulatory stasis; a difficult birth; any situation in which a female lizard is unable to adequately expel a fully developed egg. Endolymphatic Calcium Sacs Calcium storage sacs found in the throat or oral cavity of some gecko species. Epiphytic A plant species that grows on the surface of another without deriving nutrition from that plant i.e. an orchid.

Extralimital Referring to a population occurring outside the primary accepted range, e.g. a typically New Guinea species that may be found in Australia. Femoral Pores Scent pores located along the length of the underside of the back legs. Fossorial Individuals that live or are active beneath the soil surface. Gene The basic unit of genetic control. Each gene has a specific function and is found on a specific section of a specific chromosome. Genotype The genetic make-up of an individual. GSD An abbreviation for Genetic Sex Determination. Gravid Pregnant; the abdominal cavity contains formed eggs or young. Gular Pertaining to the chin or throat area of an animal. Gutload The act of feeding a calcium or vitamin supplement to an insect to improve its nutritional content. Haploid An individual possessing one copy of a sex chromosome, either a Z or W chromosome. This is what is present in an ovum (egg) or a sperm. Hatchling A very young individual that has recently emerged from its egg. Heliothermic An individual that must bask to raise its body temperature. Hemibacula Calcified (bony) hemipenes found in mature monitor specimens. page 343

Hemiclitoris The smaller, less ornate equivalent of a hemipenis as found in some female reptiles, particularly female monitors. Hemipenes The paired reproductive organs of the male lizard; the lizard equivalent of the penis. Herbivorous An animal that feeds predominantly on plant material. Herpetofauna A collective term referring to a group of reptiles—usually pertaining to a particular region, locality or habitat. Heterogeneous Components of different sizes, usually referring to body scales, body spines or tubercles. Heterozygous When the genetic make-up of an animal consists of one mutant gene and one normal gene. Holotype The original specimen from which a new species is first described. Homogeneous Components of the same size, usually referring to body scales, body spines or tubercles. Homozygous When the genetic make-up of an animal includes two identical mutant or two identical normal genes. Hybrid A genetic combination as a result of mating two different species or subspecies under unnatural circumstances, such as in captivity. Some also consider mating of specimens from different localities to be a form of hybridisation. Hypererythrisitic An individual with more than normal red pigment cells. Hypermelanistic An individual with more than normal melanin (black) pigment cells. page 344

Hypocalcaemia A nutritional state in which insufficient calcium is available for metabolic processes due to insufficient dietary supply or insufficient physiological uptake. Hypoerythrisitic An individual with less than normal red pigment cells. Hypomelanistic An individual with less than normal melanin (black) pigment cells. Hypoxanthic An individual with less than normal yellow pigment cells. ICZN An abbreviation for International Code of Zoological Nomenclature—the ruling body the controls the official naming of species of animals. Incubation The act of hatching eggs either naturally or artificially. Inguinal Pertaining to the groin area. Insectivorous An animal that feeds predominantly on insects. Intergrade The long-term genetic combination of two different species or subspecies as a result of pairing under natural circumstances, such as at the natural boundary between two overlapping distributions, resulting in a population displaying variable features between the two extremes. Juvenile A young individual that cannot yet be visually sexed and still possesses some colouration of a hatchling. Keratin A protein that forms the outer coating or scales of a lizard. Lectotype A retrospectively chosen holotype for a species for which a holotype had never been specified.

Laterally Compressed Flattened from side-to-side. Leucistic An individual devoid of pigment cells in the skin but not on other body areas e.g. eyes. Live Bearer A lizard species that gives birth to fully developed, independent offspring as opposed to eggs. MBD An abbreviation for Metabolic Bone Disease—a complex disease state involving hypocalcaemia and insufficient UV-B supply. Meiosis The procedure by which reproductive cells divide and multiply. Mitosis The procedure by which normal body cells divide and multiply. Montane Individuals inhabiting mountainous areas. Morphological Pertaining to the external appearance of an animal. Mutation Any change in the genetic make-up of an individual—usually resulting in a change in physical or body colouration. Nape The area between the eye and ear. Neotype A specimen chosen in the absence of a holotype, lectotype or paratype to represent a species. Newborn A just born individual of a live bearing species. Nocturnal Active during the night. Nomen nudum Latin for ‘naked name’, also termed ‘informal’ name—used to indicate an animal’s name that is similar to, or appears like the scientific name, or is intended to become a scientific

name but fails to be officially recognised because it has not been published with an adequate description (or reference to an adequate description) or not according to ICZN rules. Nuchal The area where the head and neck join. Ocelli Any arrangement of scales in a circular or ‘target’ pattern—an eyespot. Overwinter Referring to individuals that undertake brumation or to eggs that slow development over the colder months of the year. Paratype A specimen other than the holotype that was cited in the original species description. Parthenogenetic The ability of a female to reproduce in the absence of fertilisation by a male, producing ‘clone’ offspring. Phenotype The physical appearance of an individual, regardless of its genetic make-up. Photoperiod The cycle of exposed daylight or night time in each 24-hour period. For example, 12:12 photoperiod refers to 12 hours of daylight and 12 hours of night in each 24 hours. Pipping The slitting or splitting of the egg shell just prior to the emergence of the hatchling. Preanal Pores Scent pores located cranial to the anus, or cloaca. Prehensile Referring usually to a tail that can be manipulated as a fifth limb. Pre-ovulatory Stasis When the final development of eggs within the reproductive tract is delayed. Proximal Near the inner part of a structure or limb; situated close to the centre of the body. page 345

Pygopod Legless lizard or flap-footed lizard. Quadrupedal An individual that moves on four limbs. Recessive Mutation Genetic mutation in which the phenotype is only expressed in the homozygous state. Rheostat A thermostat. Scat Piling Collective defecation site used by multiple lizards, mostly utilised by skink species. SDZ Diet The San Diego Zoo diet, a turkey-mince-based diet for monitors. Shedding The replacement of old skin cells by separation from a new layer underneath. Single Factor Co-dominant A co-dominant individual possessing one each of the normal and mutant genes; the intermediate form. Sloughing See shedding; casting off an old skin. Slug Traditionally refers to a shell-less snail but more commonly refers to an unfertilised ovum that has been laid by an egg layer or passed by a live bearer at birthing. Spermatozoa Storage A mechanism by which male reproductive components (spermatozoa) are retained internally by a female, in a viable state, to be used to fertilise eggs many months after the initial mating. Spurs Enlarged scales found at the base of the tail; usually larger or more ornate in male specimens. Sub adult A young individual that can be visually sexed but still possesses some colouration of a juvenile; not fully adult. page 346

Subspecies A taxonomic category that is a variation in a primary (nominate) species brought about by geographical or genetic isolation, usually characterised by a variation in morphological features. Substrate The floor covering in a lizard enclosure. SVL An abbreviation for Snout Vent Length; the distance from the tip of the nose to the opening of the cloaca. Sympatry Individuals that share the same habitat in both space and time. Tail Autotomy The act of shedding all or part of the tail as an anti-predator mechanism. Taxonomy The study of genetic and morphological relationships between species. Terrarium A reptile enclosure usually with a glass front. Terrestrial Individuals that live on the ground surface. Tetraploid A rare situation in which a female gecko possesses four copies of the Z chromosome. Thermoconformity An individual that has no requirement for basking and is active at temperatures essentially equal to the surrounding air temperature. Thermostat An electronic device for controlling the upper or lower temperature limit in an enclosure. TL An abbreviation for Total Length; the distance from the tip of a lizard’s nose to the tip of its tail. Transillumination Visualisation of internal components using a bright light held outside the body to illuminate structures within.

referring to light in the wavelength 290−320 nanometres. Varanid Monitor or goanna—members of the genus Varanus. Vent The combined exit for gastrointestinal waste, kidney waste and reproductive products. Alternative name for cloaca. Ventral/Ventrum Relating to the lower half or bottom of a structure or body.

G SCHMIDA

Triploid Parthenogens A unique situation in which a female gecko possesses three copies of the Z chromosome, allowing it to sexually reproduce in the absence of a male gecko. TSD An abbreviation for Temperature Dependent Sex Determination. Tubercles Enlarged body scales. UV-B An abbreviation for Ultra Violet type B,

Oedura marmorata

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