Michigan's Turtles

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Written by J. ALAN HOLMAN JAMES H. HARDING

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Illustrated by JAMES H. HARDING Publications of the Museum MICHIGAN STATE UNIVERSITY Educational Bulletin No. 3, 1977

Sh -a2af PUBLICATIONS OF THE MUSEUM, MICHIGAN STATE UNIVERSITY EDUCATIONAL

BULLETIN

NO.

3

Editorial Committee: Rollin H. Baker, Chairperson; Charles E. Cleland, J. Alan Holman, Richard J. Snider E

Published September 15, 1977 Price $0.95

Printed by STONE PRINTING COMPANY Lansing, Michigan

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Table of Contents TINDER O DUGRIO AUITtl=

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Eastern:spiny-softshella. CONSERVATION AND shurtleseaS=HOOd=..

Turtles and the

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Captivity

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RERERENCES23

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Endangered:SpeciesAct...-...-...........-: 36

BasiczInformation = 2. Notes on Keeping Individual-Species: DISCASCS

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Fig.

1.

Scene with Cretaceous

turtles

and dinosaurs

D

o you know that turtles were present long before the first dinosaurs appeared on Earth? The first turtles are known from about two hundred million years ago; they flourished through the rise and fall of the dinosaurs (Fig. 1); and they are still relatively abundant despite intense urbanization and cultivation of the Earth by humans. Turtles are at once ancient and specialized. If turtles were known only as fossils we would be amazed their structure, for most of the body covered by the protective shell. This armor may account for the fact that turtles have survived so long. We lucky in Michigan to have ten kinds of native turtles. Some people are not so fortunate. In England there are no native turtles, the southern part of the country the climate although very mild. The English love turtles so much that they buy pets to release their gardens or to keep in their homes. In parts of the dry western United States there are very few turtles because of the dry climate. This booklet will allow the reader to identify and learn about Michigan turtles. Some of our species are holding their own in the face of humankind, while others may be in danger of becoming extinct. We hope that this booklet will instill a deep respect for turtles and a desire to conserve these living fossils.

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TURTLE STRUCTURE In order to learn about Michigan turtles we need to discuss their unique structure. Modern turtles have a shell (Figs. 2 and 3) into which the carahead, limbs, and the tail may be pulled. The shell is composed of pace (upper shell) and a plastron (lower shell), and these two portions are connected by a bony bridge on each side. The shell is composed of two kinds of plates. Very thin horny plates, the epidermal shields, lie on top of and overlap thicker bony plates called dermal bones. The overlapping structure of the shields and bones strengthens the shell. The epidermal shields are periodically shed as the shell bones grow. Both sets of plates have separate names as shown Figures 2 and 3. Some turtles, such as the box turtle, have a hinge on the plastron that allows the whole shell to be closed tightly around the head, limbs, and tail. Other turtles, such as the snapping turtle, are very poorly protected by the shell. Moreover, the softshelled turtles have a pliant, leathery shell. One can usually correlate turtles with the amount of protection their shells afthe temperament ford them. Box turtles are not very prone to bite while snappers and softshells may bite upon slight provocation.

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Fig. 3. Dermal bones

of

HYPO,

of a turtle:

EPI, epiplastron; ENT, entoplastron; HYO, hyoplastron; S, suprapygals; C, costals.

hypoplastron; XIPH, xiphiplastron; NUC, nuchal;

The plastron is composed of bones from two sources: The entoplastron and the epiplastral bones correspond the interclavicle and clavicle of the dermal shoulder of primitive reptiles. The hyoplastral, hypoplastral, and xiphiplastral bones correspond the abdominal ribs (gastralia) of primitive reptiles. Thus from historic standpoint the turtle shell is a

CERVICAL MARGINALS yee,

to to

an

complex

structure.

The limb girdles of turtles (shoulder and hip) are inside of and fuse with the shell. The skull of turtles is toothless and primitive. It is the its rear part. The anapsid skull anapsid type of skull with no openings is found in several groups of primitive reptiles.

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FOSSIL RECORD Turtles appear rather suddenly in the fossil record about two hundred million years ago in about the middle of the Triassic Period. But the question of turtle ancestry is a perplexing one, for a definite fossil ancestor has not yet been discovered. Two primitive fossil reptiles show some resemblances to turtles. One (Fig. 4) has skeletal features of the body that are somewhat turtle-like, but other crucial parts of the fossil are missing. The other fossil has a skull that indicates that it may be somewhere near turtle ancestry, but the body merely that of a primitive reptile. Moreover, the second fossil occurs too late in time to be the ancestral turtle. The first Triassic turtles (proganochelyids) had shells that possessed the same bones living turtles, as well as some extra bones called meso-

Epidermal shields of a turtle: G, gular; HU, humeral; PEC, pectoral; AB, abdominal; FEM, femoral; AN, anal; AX, axial; ING, inguinal; V, vertebral; PL, pleural.

Fig. 2.

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The dermal bones of the turtle shell are inherited from different sets of their primitive ancestors. The bones of the carapace are derived from bony plates called osteoderms, such as occur today in the skin of the backs alligators and crocodiles. These plates fuse with ribs and vertebrae to form the carapace. bones

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is unlikely that these earliest forms could pull the plastral bones. But head and neck into the shell. Also, the limb girdles were more primitive than those of modern turtles in that the bones of the dermal shoulder girdle could still be individually recognized as clavicle, cleithrum, and interclavicle. The skull of Triassic turtles was similar to those of modern turtles, except that in Triassic turtles teeth were present on the palate. Some the Triassic turtles had a shell about 60 cm. long. During the Jurassic Period (which began about 181 million years ago) more advanced types of turtles appeared. These turtles were completely toothless, but it appears that some of them still could not pull the head and the limbs into the shell. These Jurassic turtles were quite diverse with as many as nine groups being recognized by scientists. Many of these fossil groups became extinct along with the dinosaurs the end of the Cretaceous Period about 75 million years ago.

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Most of the genera of turtles found in Michigan can trace their ancestry back millions of years as shown the following list:

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turtle

genus Sternotherus Snapper genus Chelydra Spotted and Wood turtle genus Clemmys Box turtle genus Terrapene Map turtle genus Graptemys Red-eared turtle genus Pseudemys Painted turtle genus Chrysemys Blanding’s turtle genus Emydoidea Softshell genus Trionyx Musk

Pliocene (began 13 million BP) Pliocene (began 13 million BP) Paleocene (began 63 million BP) Miocene (began 25 million BP) ?Oligocene (began 36 million BP) Oligocene (began 36 million BP) ?Eocene (began 58 million BP) Pliocene (began 13 million BP) ?Cretaceous (began 135 million BP)

As one can see, Michigan’s turtles come from stocks that are millions of years old. The great age turtle ancestry and the long lives that individual turtles achieve today are most interesting attributes of this group.

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TURTLE CLASSIFICATION At present, turtle classification is in a state of uncertainty and revision, as scientists are trying new conceptual schemes ordering turtles in a sethat most fits their quence closely evolutionary relationships. Nevertheless, we can place our Michigan turtles in the general scheme of classification without too much difficulty. Turtles belong in the Class Reptilia with crocodilians, the tuatara of New Zealand, lizards, and snakes, as well as a host of extinct forms including the dinosaurs. All Michigan turtles may be placed in the large group Cryptodira (hidden-necked turtles), as they all pull the head straight into the vertical S-shaped curve. They can furthermore be placed in four families: Kinosternidae (Oligocene-Recent); Chelydridae (Paleocene-Recent); Emydidae (?PaleoceneRecent), and Trionychidae (Cretaceous-Recent).

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KINOSTERNIDAE

Fig. 4.

Hypothetical ancestral turtle

Musk

turtle

Sternotherus odoratus

CHELYDRIDAE

Modern turtles are all able to pull the head and into the shell to modern turtles are toothless. Modern types appearsome degree, and ed in the Jurassic and existed along with the dinosaurs the Jurassic and

all

the Cretaceous.

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Modern turtles all fit into two groups: Cryptodira turtles) that pull the neck vertically back into the shell by bending the neck in an S-shaped curve; and Pleurodira (side-necked turtles) that swing the neck sideways into the shell along a horizontal plane. Most zoologists believe that the side-necked turtles are more primitive, as they have, among other features, simple neck vertebrae and mesoplastral bones. All Michigan turtles are hidden-necked (Cryptodira) turtles. (hidden-necked

Northern snapping turtle Chelydra serpentina serpentina

EMyYDIDAE

Spotted turtle Clemmys guttata turtle Clemmys insculpta Eastern box turtle Terrapene carolina carolina Map turtle Graptemys geographica Red-eared turtle Pseudemys scripta elegans Midland painted turtle Chrysemys picta marginata Western painted turtle Chrysemys picta belli Blanding’s turtle Emydoidea blandingi Wood

TRIONYCHIDAE

Eastern spiny softshell Trionyx spiniferus spiniferus 9

snout. Nostrils are pronounced. There are two yellow or white lines that extend backward from the snout, one passing above and one passing below the eye. The skin is covered with small fleshy projections called papillae. Those papillae that occur on the neck are in distinct rows. The legs are small and the toes are not strongly webbed. The color of the dull olive, brown, or black. The skin between the plastral carapace shields is usually pinkish. Males have the bases of the tail much thicker than females and the male tail ends in a nail. The young have pronounced ridge or keel on the carapace.

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Species List

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In the following species list there is an emphasis on facts as they relate to turtles in Michigan, but of course, in some cases data are from studies done in other nearby states. In general, data for turtle ranges in Michigan are from Conant, 1975. We realize that additional studies are likely to modify slightly the concepts of the ranges that we present. The junior author’s personal field notes and research are recorded in some parts of the sections on the wood turtle and the painted turtle. Fig. 6. Plastron of common

Fig. 5. Common

Common

musk

turtle

musk

turtle

Identification. This is the only Michigan turtle (Figs. 5 and 6) whose plastral shields are separated by areas of skin. An average adult is 100 mm. long (about 4 inches). The head is large with a conical, tapering 10

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turtle

Range. In Michigan (Fig. 7) the musk turtle occurs in the Thumb area and then south of a curved line that runs roughly through Midland, Mount Pleasant, and White Cloud. Within this range the musk turtle appears to be quite spotty in its distribution. Habitat. This turtle is almost always listed as being fond of mudbottomed habitats; but the authors have observed musk turtles in Michigan only in quiet, clear lakes with sand or gravel bottoms. We have never seen them in the numerous muck-bottomed lakes that are so comsouthern Michigan. mon Food. Musk turtles are reported to eat a very wide variety of animal and vegetable food, but in Michigan, Lagler (1943) found that insects and snails were the items most often found in their stomachs. Reproduction and Growth. In Michigan, males are sexually mature in their third or fourth years, but females do not mature until their ninth to

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(Stinkpot) Sternotherus odoratus

musk

11

eleventh year (Risley, 1934, 1938). Mating probably occurs about April or May Michigan, with another period of mating in September early October. Mating occurs under water in shallows night or in the early morning. Nesting in Michigan takes place from May through August. The nests are shallow and sloppy and are formed by scraping away debris. Often nests are under old logs or other objects. Sometimes several females put their nests under the same log.

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along the bottom nosing around for food. The sunning habit is poorly developed, but they will sometimes climb several feet above the water in the limbs of dead trees. In northern Indiana, musk turtles are active from March 18 to December 31 (Everman and Clark, 1916), and they have been seen crawling under the ice. These turtles hibernate in mud and sand under the water, and sometimes large congregations of hibernating individuals have been found. Males apparently recognize females by the odor given off by glands at the base of the tail. Males engage in precopulatory nudgings and chasings, and during active copulation there is rubbing and biting of the female’s head. When caught, musk turtles exude a substance with an unpleasant odor from musk glands near the bite their captors freely bridge of the shell. The turtles usually attempt and this habit sometimes persists in captivity.

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Fig. 7. Michigan range of common

musk

turtle

The average length of 75 eggs taken by Risley (1933) in Michigan was 27.1 mm., ranging from 24 to 31 mm. The eggs areelliptical, white, and they have thick but brittle shell. In Michigan the eggs probably hatch in September and October. The incubation period for Michigan eggs kept the laboratory was from 60 to 70 days (Risley, 1933). Risley also measured 200 recently hatched stinkpots and found that the average carapace length was 23 mm. with a range of from 19 to 25 mm. Risley reported that in Michigan musk turtles with carapaces over 80 mm. long were at least 10 years old. He showed one-year-old turtles averaged 32.5 mm.; two-year-olds 42.5 mm.; three-year-olds 52 mm.; four-yearolds 61 mm.; five-year-olds 67 mm.; six-year-olds 71 mm.; seven-yearolds 74.5 mm.; eight-year-olds 77.6 mm.; and nine-year-olds 80.0 mm. Behavior. The musk turtle is normally most active at night, although evidently early and late in the season there are increased daily periods of activity. This turtle is a poor swimmer and often seen crawling slowly

Fig. 8. Northern snapping turtle

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Northern snapping turtle Chelydra serpentina serpentina has a tal Identification. This is the only Michigan turtle (Figs. 8 and 9) that is as long or longer than the carapace and with a prominent row of triangular tubercles or spikes on its upper surface. This is the largest Michigan turtle with some individuals reaching a weight of 23 kg. (about 50 large and the upper jaw has a small beak. The jaws pounds). The head may be barred. The upper neck is covered with wartlike tubercles. The carapace has three low keels (ridges) on it that become less and less prominent with age. The carapace may tan, brown, olive, or black. The bridge is narrow and the plastron is small and cross-shaped and does not afford complete protection for the head and legs. The plastron ranges from yellowish to.tan incolor. The toes are not strongly webbed but they are very strongly clawed. Males have the anal opening back of the end of

be

SF.

13

The number of eggs ranges from about 20 to 60. They are round and look something like ping pong balls, an average egg being about 25 mm. in diameter. Young-turtles come out of the nest from late August late September in Michigan. Gibbons (1968) found that snappers from the Kalamazoo River near Otsego, Michigan, were 54-66 mm. long after one year; 83-108 mm. after two years; 124-145 mm. after three years; 146-184 mm. after four years; 177-211 mm. after five years; and 204-238 mm. after six years.

the carapace. Baby snapping turtles have very prominent carapacial keels and have the habit of rendering themselves immobile or ‘‘playing dead’’ when handled by humans. Range. The snapping turtle ranges throughout the state of Michigan

to

(Fig. 10).

Habitat. The snapper may be found in almost any body of water in the state, although slow-moving, vegetation-filled lakes or ponds with soft bottoms seem to be preferred. Food. The snapping turtle feeds upon a wide variety of plants and animals. In Michigan, Lagler (1943) showed that fishes, invertebrates, and plants were the items eaten most often. Snappers may occasionally eat is young waterfowl, but evidence that they are a serious threat to bird lacking, and in fact large bass and pike may be more serious predators.

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Fig. 10. Michigan range of northern snapping turtle

Reproduction and Growth. The snapping turtle is ready to breed shell reaches about 200 mm. length. Mating occurs from and in water. late October takes place Michigan April through are in June appears to be the peak nesting month Michigan. Nests made in open areas, often several hundred feet from water. Snappers make overland trips during the nesting season and during this time they may be picked up by turtle hunters who whencrossing the road killed cars‘and. egs The nest is dug withthe hind feet in sandy or eatthe turtles the eggs. sometimes piles of rotting vegetation. The size of the loamy areas or by is nest often determined the size of the female involved. In loose sand the female may practically bury herself by digging in with her fore feet before digging the nest with her hind feet.

Behavior. The snapping turtle is a very aquatic species. During the day this turtle spends most of its time lying quietly on the bottom, or sometimes it rests just under the surface in mats of aquatic vegetation. At night it becomes more active and forages for food. When disturbed, an adult snapper can swim rather rapidly. Snapping turtles do not bask upon logs and other emergent objects as much as some other aquatic species of turtles do. In Michigan, snapping turtles usually go into hibernation by late October and usually come out of hibernation in April or May; but in southern Michigan individuals have been taken as early as March 15. Snappers hibernate by burying themselves in the mud or muck at the bottom of ponds or lakes; they may also use muskrat burrows for hibernation. When adult snappers are found on land they quite irritable and will strike at the slightest provocation. Their sharp jaws can inflict deep

14

15

Fig. 9. Plastron of northern snapping turtle

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Habitat. The spotted turtle is mainly restricted to undisturbed boggy ‘situations where it seems to favor the tiny streams that run through such Michigan so that the areas. Such habitats are becoming uncommon turtles are restricted to small, isolated colonies. Food. The spotted turtle eats both plant and animal material. Surface (1908) found that Pennsylvania spotted turtles ate worms, slugs, snails, small crustaceans, crayfish, millipedes, spiders, and insects, including terrestrial types of insects: Other workers have reported that spotted turtles consume vegetable matter, including grass, algae, and cantaloupes.

wounds and the turtles should be handled with care. A snapper may be tail with its head facing away from its captor carried by the base of and its body held well away from the person carrying it. Oddly enough, snappers disturbed under water rarely bite, and baby snapping turtles reared from hatchlings may never ‘‘learn’’ to bite. The snapping turtle an important part of the aquatic community in Michigan and fulfills the ecological role of predator, grazer upon aquatic plants, and scavenger.

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Fig. 11. Spotted turtle

Spotted turtle Clemmys guttata Identification. The spotted turtle (Figs. 11 and 12) may be recognized The by its smooth, bluish-black carapace with round yellow spots. Blanding’s turtle has yellowish spots, but it has a bright yellow neck and a plastral hinge that are absent in the spotted turtle. An average adult spotted turtle is 125 mm. long (about 5 inches). The head of the spotted turtle is small and black and in some specimens there is a yellow band behind the eye. All specimens have a broken yellow band near eardrum. The legs are small and the toes are not strongly webbed. The plastron is yellowish or orangish with black blotches. Male spotted turtles have tan chins and brown eyes; females have yellowish chins and orange

Fig. 12. Baby spotted turtle

the

eyes.

Range. The spotted turtle is found in only a few restricted places in is a potenits narrow habitat requirements Michigan, and because tially endangered species. Roughly, the spotted turtle occurs in the southwestern two-thirds of the Lower Peninsula (Fig. 13). It is absent from most of the northern one-third of Michigan, and it is absent from the ‘‘thumb’’ area.

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Reproduction and Growth, When spotted turtles reach a carapace length of about 90 mm. they are ready to mate. Courtship usually begins in early April in Michigan. Mating occurs under the water and lasts from one-quarter to one-half an hour. Often the males frantically chase the females about on land and in the water during the courtship phase of reproduction. June is probably the peak nesting month in Michigan. Nests are built in relatively open areas near the boggy places where the turtles live. They are flask-shaped and are only about two inches deep. Only about 3 to 5 eggs are deposited in the nest. They are elliptical and white and are about 37 mm. long. It takes about 75 days for the eggs to hatch. Growth rates in Rhode Island spotted turtles (Graham, 1970) were: hatchling, 22.9-26.7 mm.; one year, 30.5-46.2 mm.; two years, 35.6-52.8 mm.; three years, 39.6-58.9 mm.; four years, 44.6-64.8 mm.; five years, 48.5-70.1 mm.; six years, 53.1-78.2 mm.; seven years, 57.0-83.8 mm. 17

black blotch at the outer rear corner of each shield, and has a terminal V-shaped notch. Adult males have longer, thicker tails than females, and the anal openconcave ing is beyond the edge of the carapace. The male plastron the center. Old males develop high carapaces and broad heads, while females have narrower heads and a flatter carapace which flares out at the rear. The brown gray colored hatchlings lack the orange skin coltails may be nearly as long as the carapace. their and or of the adults

Behavior. The spotted turtle spends time both on land and in the water. It is fond of basking, and may be seen on top of stumps, logs, or in bunches of emergent vegetation or clumps grass. Spotted turtles are shy, gentle animals, but they are quite active. They rarely attempt bite when picked up by humans, but they usually kick their legs and move

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Fig. 13. Michigan range of spotted turtle

to

Fig. 14.

their heads around in an attempt escape their captor. Spotted turtles the authors are thrilled when they see are sO uncommon Michigan one; and in ten years of herpetological observations in the state, the senior author has seen only three or four individuals in the field. Sometimes spotted turtles are seen on land, walking near the boggy areas where they live. These little turtles are relatively cold-tolerant and they may be seen as early as late March in southern Michigan. They probably go into hibernation in October. Spotted turtles are very hard to find in the hot summer months.

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turtle Clemmys insculpta Indentification. The scientific name this species means ‘‘sculptured turtle,’’ because its rough, brownish carapace often looks like it was carved from wood (Figs. 14 and 15). An average adult is 200 mm. long (about 8 inches). The head black; the upper surfaces of the front legs, feet, and tail are also dark, but the lower neck and other soft parts are usually some shade of orange or yellow. The plastron yellow, with a Wood

is

18

turtle

Range. In Michigan (Fig. 16) the wood turtle occurs mainly in scattered populations in the northern Lower and Upper Peninsulas. They are locally common in some areas of undisturbed habitat, but they must be considered a rare species that needs protection. Habitat. Michigan wood turtles prefer the vicinity of rivers and streams and their associated swamps and woodlands. Food. This turtle eats a wide variety of plant and animal foods, including insects and their larvae, worms, molluscs, algae, various leaves, fond of berries, and the junior author fruits, and mushrooms. They has found turtles with their mouths stained from feeding on whatever fruit was in season. They eat only dead fish and a study by Lagler (1943) concluded that wood turtles were not harmful to Michigan fishes. Reproduction. Courtship and mating in Michigan may take place any late time between May and October, but usually occurs in June and the which in two described sexes summer. A courtship ‘‘dance’’ has been

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Wood

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19

face each other and swing their heads from side to side for up to two hours (Carr, 1952). Mating takes places in shallow water, often on the sloping bank of a stream. In Michigan, the nesting season extends through June and into the first week of July. Most eggs are laid during last half of June. Typically, the mother turtle begins seeking a nest site in the late afternoon of a warm day. She will look for a sunny, open spot with moist, well-drained sand or soil. Several nests may be started and then abandoned before the final site is chosen. The nest cavity is dug by alternate strokes of the hind feet and its depth is determined by the size of the feet. The eggs are laid one a time, and each carefully arranged in the nest by front parts of the hind feet with the claws turned inward to avoid injuring the eggs.

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The growth rate for young wood turtles probably varies considerably depending upon environmental factors. A one-year old turtle from the Upper Peninsula had a carapace length of 49 mm., while one hatched in captivity and fed in the winter had a carapace length of 97 mm. after one year. This captive reached sexual maturity in two years, whereas a wild turtle at least seven years old was not sexually mature.

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the

Turtle male

Wood

i

Fig. 16. Michigan range of

.

wood

turtle

The usual clutch contains from 7 to 13 eggs, although the junior author has seen a clutch of 18. The nest is back-filled and smoothed over with care, and it may be after dark before the female leaves the site. The incubation for eggs hatched in captivity averages about 57 days. Inthe field, hatchlings have been seen emerging early in September the Upper Peninsula. Racoons, skunks, and other predators destroy many nests. Hatchlings are about 32 mm. carapace length.

Behavior. This solitary species spends many hours basking in the late afternoon on logs along stream banks or in woodmorning and land openings. Sometimes they partially cover their carapaces with sand or dirt and lie in shallow pits which obscure their outlines. A turtle leavback with quick strokes ing the water will frequently throw sand over of the front feet. Hatchlings also have this habit. Individuals may have a rather small home range, as one turtle was observed sunning on the same log jam for several years. These turtles hibernate from October to May, usually in the mud of a stream bottom, in an old muskrat burrow, or even on land, buried under decaying vegetation. Wood turtles are relatively intelligent and have run test mazes as well as a laboratory rat (Carr, 1952). They are also quite agile and can climb over low obstacles easily. Most specimens are shy when handled and rarely bite.

20

21

Turtle female

Blanding’s

Fig. 15. Plastra of Blanding’s turtle and

in

wood

its

turtle

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usually prominent beak. The shell is high-domed, and the carapace brownish with lots of irregular yellowish marks and blotches. The tan to brownish in color. The legs are moderateplastron is hinged and ly strong and the toes are not webbed. The males have a concave flat plastron and they usually have a bright red eye. The females have plastron and the eye is usually yellowish or yellowish-brown.

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a

Fig. 18. Closed shell of an eastern box turtle. Note median hinge,

Range. The

box

turtle

has a spotty distribution in Michigan (Fig. 20)

that roughly is enclosed by the southwestern one-third of the Lower

Peninsula. In a few areas the box turtle is common, but this turtle must be considered rare in the state, and in fact, it is now protected in Michigan under the ‘‘Endangered Species Law’’.

Fig. 17. Eastern box turtle and

its nest

Eastern box turtle Terrapene carolina carolina Identification. This is the only Michigan turtle (Figs. 17, 18, and 19) that can completely close its shell, front and back, over the head, legs, and tail. This is accomplished by a hinge in the plastron. An adult box turtle in Michigan would be 150 mm. (about 6 inches) long. The Blanding’s turtle has a hinge in the plastron, but it cannot fully retract the head and legs within its shell. The head of the box turtle is small with a rather

Fig. 19. Hatching eastern box turtle

22

23

Habitat. This turtle inhabits dry, often sandy woodlands where oak

and hickory trees are the dominant species. Box turtles often move to low, swampy areas in hot weather.

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suspect that this may be more rapid growth than occurs in Michigan. Several authors have reported that box turtles have lived to be over 100 turtle that has been in captivity 31 years old. The junior author has years and that was an adult when captured. Behavior. Box turtles are most active in the morning until about ten o’clock. They also appear to have periods of activity after rainstorms in the daytime. These turtles often rest under logs or piles of leaves or other shelters during their inactive periods. Sometimes they enter woodland under piles of submerged leaves to escape summer heat. ponds and Box turtles are gentle animals that usually retreat into their shells rather than trying to bite or to run away from potential danger. These habits are disastrous to box turtles attempting to cross roads and highways, as a shell near miss by a car will usually cause the turtle to withdraw into other vulnerable passing cars. to for awhile; and this makes them highly Males are often less shy than females. Box turtles go into hibernation in October and emerge in late April or early May in Michigan.

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turtle Graptemys geographica Identification. This is the only Michigan turtle (Fig. 21) with lots of longitudinal yellowish stripes on the head, jaws, and neck, but without shell. An adult is about 225 mm. any red markings on the head or not apis long (about 9 inches). The head moderately large and a beak for modified feeding surface parent, but the jaws have a broad crushing

Map

Fig. 20. Michigan range of eastern

box

the

turtle

Food. The turtle eats a very wide variety of animal and vegetable foods. We have found that captive specimens will eat almost everything a human will eat, raw or cooked. There are many reports in the literature that box turtles eat both poisonous and non-poisonous mushrooms, but we have never been able to induce captive box turtles to eat any kind of mushrooms. peak in May Reproduction and Growth. Mating probably reaches in Michigan. Mating in the eastern box turtle has been described as consisting of three phases: (1) a circling, biting, shoving phase by the male; (2) a phase where the male trys to mount the female; and (3) a final phase where copulation occurs. Mating takes place on land and females may lay fertile eggs up to four years after a single mating. Nesting probably reaches its peak in June in Michigan. Nests are usually started in the evening and are completed after dark. Most often dug in sandy soil, the nest is flask-shaped and is about 100 mm. deep. The eggs elliptical, have white, flexible shells, and are about 37 mm. long. About four or five eggs are put in each nest. It takes the eggs about 90 days to hatch. Hatchlings are about 26 mm. length, and they have rarely been described in Michigan. Generally, box turtles are said about five years, but we to reach a carapace length of about 125 mm. box

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Fig. 21.

Map

turtle

and clams. The legs are strong and the toes are webbed. The plastron lacks a hinge. There is a moderate keel on the carapace, and the rear of the carapace is saw-toothed. The carapace has a network of fine yellow lines, hence the common name “‘map turtle’’. Males have a longer, thicker tail than females, and in the males the anal opening is beyond the back margin of the carapace. Range. The map turtle occurs in the southern peninsula only (Fig. 22). Its range extends northward to the Traverse City area in the west, and

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extends throughout the thumb area the east, but it is absent from the northcentral and northern portions of the Lower Peninsula. Habitat. The map turtle is almost entirely a turtle of the larger rivers and streams of Michigan, although some lakes are inhabited.

Red-eared turtle Pseudemys scripta elegans Identification. This turtle (Fig. 23) may be identified by the large, thick, red or orange band that occurs behind the eye in most specimens, coupled with the complete lack of red markings on the shell. Old males may lack the red markings, but they may be recognized by their nearly black heads and by the black-bordered epidermal scutes with yellowish centers.

Fig. 23. Baby red-eared turtle Fig. 22.

Michigan range of

map

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Remarks. Most scientists believe that red-eared turtles are not native to Michigan and that they were introduced by the release of turtles bought in pet shops. There are two viable populations of these turtles in southeastern MichMichigan, one in southwestern Michigan and one the southern part of the igan, but specimens could turn up anywhere large female in the Red Cedar River a state. The senior author caught few miles east of East Lansing. This turtle occurs naturally in southcentral United States from southeastern New Mexico east to Alabama and north to Illinois and Indiana. It prefers standing or slow-moving aquatic habitats.

Food. The map turtle mainly feeds on snails and clams, but aquatic insects, crayfish, and some dead are eaten. Reproduction and Growth, Little has been recorded about the reproduction and growth of the map turtle. It has been reported that nesting females are always over 190 mm. least length and always nine years old. Courtship and mating evidently occur both in the spring and in the fall. Mating believed to occur under water. Sandy soil well away from the beach line is utilized for nests. The depth of nest said to be determined by length of the female’s hind legs. The nest is flask-shaped. About 13 eggs are put in each nest. Larger females are reported to lay larger numbers of eggs. The eggs are elongate and are about 32 mm. long and about 19 mm. wide. The young are almost perfectly round and about 26 mm. long. They have a much more prominent dorsal keel than do the adults. The young usually appear in August or September. Behavior. Map turtles spend much of the daytime basking upon logs and stumps and other emergent objects. The adults are extremely shy and difficult to approach. They are thought to feed primarily in the twilight hours and at night. Map turtles are active from April through September in Michigan.

is the only Michigan turtle with a smooth black or olive carapace decorated with red and black with yellow stripes, yellow markings along the edges. The head and the neck and legs have red and yellow stripes. The plastron is yellowish, with a dark central blotch. The map turtle and the red-eared turtle have striped heads and legs, but neither has any red on the carapace margins or on the legs. An adult painted turtle is 140 mm. long (about 5% inches). Males have very long claws on the front feet. Females have shorter front claws and are larger than males. The young are patterned like the adults.

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Painted turtle Chrysemys picta Identification. The painted turtle (Figs. 24 and 25)

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an Range. The painted turtle is the commonest turtle in Michigan found throughout the state (Fig. 26).

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shields. The western painted turtle has a plastral pattern that may cover of the plastron’and extends. out along the seams. of the shields. Many painted turtles from the Upper Peninsula‘appear be intergrades between the two subspecies as they interbreed freely-wheére their ranges meet (Fig. 26). The junior author has examined numbers of. painted turtles in the central Upper Peninsula and has noted, that.in-one pond one may find specimens. with both plastral pattertis or with those in between. There’ appears to be no important’ differences between the habits. of the ~two subspecies-in- Michigan, thus the following. discussion’ Will apply to both. much.

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Fig. 24. Painted turtle

Subspecies. Two subspecies (races) are found in Michigan: the midland painted turtle (C. picta marginata) ranges throughout the Lower Peninsula and into the eastern Upper Peninsula; the western painted turtle (C. picta belli) is found in the western part of the Upper Peninsula. The easiest way to separate the two races is to examine plastron (Fig. 25). The midland painted turtle has a narrow dark central blotch which is oblong and does not extend out along the seams between the plastral

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Fig. 26. Michigan range of painted turtle; crosshatching indicates where midland and western races interbreed.

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Habitat. Painted turtles prefer quiet, bodies_,of water with soft bottoms,and vegetation) such as ponds, sloughs, Aiitch es, marshes and the near-shore areasof lal és. They also beeur ii Bos rivers and streams and they” are quite tolerant of organ pollution: Food. The painted turtle eats both plant and animal food. A Michigan study (Lagler, 1943) showed algae and other plants, insects, and crustaceans made up most of the food. They appear to eat the food which is most abundant. Gibbons (1967) found that painted turtles grow found that faster on an animal diet than on a plant and tiirtles living inan organically ‘enriched river wheré thé food consists ‘mostly of small animals grew faster and reached larger sizes than turtles living ina marsh and eating mostly duckweed. Paintedturtles get their food inor near the. yok water and seem unable to swallow foodunless the head is submerged. esoe )

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Midland painted turtle plastron, left; western painted turtle plastron, right 28

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Reproduction and Growth. This species takes from 3 to 13 years to reach sexual maturity. Males mattiré quickerthanfemates;” but for both sexes maturity depends more on ‘reaching a minimum size than on age (Gibbons, 1968). Most courtship and matingtakes place the spring. A swims backwards male of the female and vibrates the front courting claws his forefeet her chin and head. The female long on may respond the by stroking the forelegs of the male with her claws. Mating occurs water. Nesting takes place from late May until early July with the peak activityin June. The female usually leaves the water in late afternoon or early find a suitable nest site, evening and may roam a considerable distance often in an open area that gets plenty of sunlight. The nest is dug with the hind feet. The turtle may moisten the cavity with liquid from her urinary bladder. The eggs are usually-laid one at a time, with each being arranged inthe nest with a hind foot before the ‘next one appears. The cavity. is filled, usihg the said, or soil ‘that has accumulated aroundthé edge\ ofthe nest during. excavation. Alternate sweeps the hind feet carry dirt into the hole, with the heel and front part of the foot being used to pack tightly around the eggs. Before the turtle returns to the water, the nest is level and nearly invisible, except that in fine sand a circular area of ripple marks may be evident over the site. The female rwmever looks at her nest or eggs. The senior author once watched a Wisconsin female attempt to dig a nest near the loose soil at the base of a post that supported a mail box. Eggs number from about 5 to 15. Painted turtles in the north and the \, western race are known to have more eggs per clutch than the midland race (Ernst and Barbour, 1972). Females in southern Michigan averaged about 6 eggs per nest while the average clutch in the Upper Peninsula was, 9 (Gibbons, 1968). Gibbons believes that some females may lay two clutches a year. The incubation period for eggs hatched in captivity is from 48 to 76 days. Many hatchlings may spend the winter in the nest, not emerging until the following spring. Gibbons (1968) found that about 98 per cent of the eggs laid in southern Michigan never hatched, the majority being first year it had destroyed by predators. But if a young turtle survived chance of Painted turtles reaching maturity. a good grow rapidly until sexual maturity and then growth slows Painted turtles may live years or more. Behavior. This turtle}is the one most often, seen sunning on logsin ‘time. The rest of the daylight Michigan, for basking occupies much of is spent foraging for food i ‘shallow water, looking along the-bottom or probing ‘tmasses-Of aquati¢ vegetation. They are’normally inactive at

Blanding’s turtle Emydoidea blandingi Identification. This is the only Michigan turtle (Figs. 27 and 15) witha very bright yellow chin and throat and a shell with a well-developed inplastral hinge. An average Michigan adult is 200 mm. long (about ches). The head is moderately large and the neck is quite long. The facial expression is different than that of any other Michigan turtle because of the protruding eyes and large lower jaw. There are no papillae or tubercles on the body. The shell is quite smooth and lacks keels or serrations. The carapace is bluish-black and has all of the epidermal scutes marked with small yellowish spots or short radiating lines. The legs are moderately large and the hind toes are weakly webbed. The male anal opening is behind the back edge of the carapace. Range. This turtle is reported to occur throughout the entire Lower Peninsula, but is has been reported in the Upper Peninsula only from the central portion (Fig. 28). Habitat. Blanding’s turtle inhabits very shallow, still water where there is plenty of vegetation. It is rather common in some marshy and bog-lake situations in southern Michigan, but it is absent where these habitats have been eliminated.

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the night. Painted turtles hibernate by burying themselves in the mud often become shallows. They may apactive quite.early in-the spring, pearing during the first warm days of March, then being forced back into hibernation with the return of cold weather. Painted turtles remain within a restricted home range for most of the year unless drought forces them to move. In spring they may move long distances in search of mates or nesting sites. During these migrations [Painted many turtles are killed while trying to cross roads and freeways. turtles may attempt to bite when handled, but most will try to escape by thrashing with the feet, or they may simply retire into their shells.

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Blanding’s turtle

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Food. Lagler (1943) found that in Michigan crayfish and other small crustaceans made up more than one-half the diet. Other food included insects which made about one-quarter the food; and snails, leeches, fish, other vertebrates and plants which made up rest. Other authors remarked about the abundance crayfish in the diet of Blanding’s turtle.

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Eastern spiny softshell Trionyx spiniferus spiniferus Identification. This is the only Michigan turtle (Fig. 29 and on cover) with a soft, leathery shell, a very long neck, and a tube-like nose. A typical Michigan adult is 200 mm. (about 8 inches) long. The head a pig-like tubular nose. There small, but it is elongate and terminates side head. Unlike other Michigan the two of each are light stripes on has The turtles the mouth carapace ranges from olive to tan fleshy lips. circles black on it. These small circles are and it has a pattern of small in Females are larger and individuals. older replaced by vague blotches duller than males.

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Fig. 28. Michigan range of Blanding’s turtle

Reproduction and Growth. Information on reproduction and growth of the Blanding’s turtle is limited. Mating evidently takes place under water and there is some nudging and bumping of the females by the males during the courtship. In Michigan the peak month for mating is probably April. Nesting probably reaches peak in late May. The nest is flask-shaped and is said to be about 175 mm. deep and 100 mm. wide. The nest is dug by the hind feet and may take almost an hour to complete. About eight elongate whitish eggs about 37 mm. long are placed in each nest. Behavior. Behavioral information on Blanding’s turtle is scant. The turtle basks occasionally, but not as much as the painted or map turtles. The Blanding’s turtle is shy and gentle and rarely attempts to bite when handled. It emerges from hibernation as early as mid-March in southern Michigan and usually goes into hibernation in October. This turtle can catch live aquatic animals with quick thrusts of long neck.

Fig. 29. Spiny softshell turtle

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Range. In Michigan (Fig. 30) the spiny softshell occurs in roughly the southern three-fourths of the Lower Peninsula. Habitat. This turtle occurs in a great variety of aquatic situations in Michigan, but is appears to prefer those where a soft bottom of muck, available. mud, sand Food. Almost all authors mention crayfish in the diet of the spiny softshell turtle. Lagler (1943) found crayfish in 47 per cent of the diet and 52 per cent insects in Michigan turtles, but other authors have found a wider variety of aquatic animal food. able to breed when they have a Reproduction and Growth, Males plastral length of about 100 mm., but females are not sexually mature until they attain a plastral length of about 225 to 250 mm. Mating probably takes place most often in May in Michigan, and copulation evident-

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ly occurs under water. Nesting probably reaches peak in June. Sites in full sunlight are selected and sand or gravel banks near the water seem to be preferred. The nest, which is excavated with the turtle’s hind feet, is about 200 mm. deep. The eggs are white, brittle, and flask-shaped and spherical, and they slightly over 25 mm. in diameter. Clutch size variable, but as many as 30 eggs may laid. The incubation period is not known, but hatchlings have been seen in September and October. The hatchlings are about 32 mm. long. Little is known about growth rates, but Breckenridge (1955) reports that 10-year-old females in Minnesota are about 250 mm. long and that a 375 mm. female would be 30 years old. He also believed that a 15-year-old male would be only about 175 mm. long.

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Conservation and Care

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CONSERVATION

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In the 200 million years since they appeared, turtles have adapted to many changes. Today, the spread of the human species has changed the environment, offering a new threat to the survival of turtles. Some turtles will require human help if they are to survive.

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ite dave of the =“ Humans have used turtles for food in Michigan since -| Native Americans, who also utilized the shells as containers, some highly decorated. The snapping turtle and the softshell are the most important -| food species. These species occasionally are over-harvested by commercial trappers for restaurants and markets. Turtles should be collected over wide areas of habitat rather than concentrating in a few areas. Snapeggs and have wider habitat requirements than pers lay large numbers softshells who have narrower requirements and have suffered from to regulate pollution and shoreline development. A wise course might turtle-harvest to maintain viable populations. Perhaps complete protection should be offered during the nesting season. The remaining turtle species in Michigan are too small and/or too rare to be hunted for food. ’

Fig. 30. Michigan

range

of spiny softshell

Behavior. The spiny softshell is a very aquatic turtle. Softshells have been observed foraging actively for food by poking the snout under rocks and other objects, and they have been observed swimming after and catching small aquatic animals. A well- developed habit of the softshell is to bury itself in the mud or sand with only the head or tip of the snout protruding. These turtles bask a lot and their favorite basking sites are sand or mud bars. They very wary and scuttle into the water and swim away rapidly when danger approaches. In Michigan, softshells probably emerge from hibernation in April or early May go into hibernation in October. Hibernation said to occur under water under several inches of sand, mud, or muck.

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‘‘Poppers and Plinkers’’ The automobile has been a hazard for turtles since its invention. Populations may be depleted if roadways are built near areas where turtles are abundant. Some of this mortality is unavoidable, as it is turtle when traveling fast. But there are a dangerous to swerve around

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number of insensitive or sadistic persons who will go out of their way to run over turtles just to hear them ‘‘pop’’. These people are a hazard to other people as well as to turtles, and one would hope that in some way their sensitivity could be increased. Another cause of needless destruction to turtle populations are thoughtless people that use turtles as targets for firearms or other weapons. These irresponsible persons are often endangering other people at the same time they are needlessly destroying a is to see a 13-year-old boy with a 22 harmless wild creature. How sad rifle destroying an animal thathas lived on this earth for 50 or 60 years! Probably ‘‘awareness education’? will prove to be the best answer to “‘poppers and plinkers,’’ but legislation might also play a role someday.

Basic Information

The best way to study. turtles is to watch them in the field where their behavior is natural. But sometimes may necessary keep turtles in captivity for close study or for educational display. Some Michigan species adapt well to captivity, but others are hard to maintain. The painted turtle is a very common species that happily adapts well to captivity. Below are some guidelines for setting up a home semi-aquatic turtles and also a list of all Michigan turtles with comments on each species requirements in captivity. Uncommon or rare species should not be kept captivity except for specific scientific studies.

Various types of water-tight~containers may be used, but the glass aquaria sold for tropical fish are excellent. The size and number of turtles determines the size of the container. A 10-gallon aquarium will hold two 75 mm. painted turtles, but one 150 mm. turtle would be the same tank. A basic rule is ‘‘keep it simple.’? One who cramped lots of natural material asks tries to build a miniature pond by hauling hints for trouble. for sanitation Following are a semi-aquatic set up. allow turtles to swim freely, but not Water should be deep enough to make air. the turtle struggle to get Usually an inch or two deep enough to the is shell when over the top of the turtle resting on the bottom is enough Some water. believe that a basking area should be provided to allow turtles to leave the water and dry off completely. Sanitation is important, so the tank should be cleaned often enough to the keep the water from getting foul. It is important that the new water old sudden as temperature changes can injure same temperature as the the turtles. The best temperature for native species is between 75 and 85 degrees F. If kept too cool (less than 70 degrees F), turtles may quit eating and become ill. It is recommended that captive turtles be kept active all winter. Turtles will stay active in winter if warmth and a light-anddark cycle similar to the summer provided. A light over the turtle will also raise the temperature. will bask and the turtle tank to encourage in may the summer prevented by changing to a lower Overheating is allows the turtle to manufacwattage bulb. Direct sunlight good as its D in skin. turtles If ture vitamin are put outside, provide a shady retreat to protect them from cats and birds. A balanced, fortified diet is necessary for healthy captive turtles. A variety of foods should be offered. Natural foods are desirable, but make sure that worms and other live foods are free of pesticide contamination. Good foods are lean beef, liver, poultry (cooked or raw), fresh or canned fish (packed in water), hard boiled eggs, and canned dog or cat food. Commercial ‘‘turtle food’’ (usually dried flies or ant eggs), house flies and fatty meats should not be used. Vegetables are good, bite size are favored by especially green leafy types. Fresh fruits cut up some species. Young turtles especially need extra vitamins in captivity. Vitamin-mineral supplements sold in pet shops liquid or powder form may be mixed in the turtles food. Extra calcium, a mineral essential for turtle’s food in the form of bone proper growth, may be added to meal. Another way of supplying calcium is to put small balls of plaster of Paris in the turtle’s water. Some additional feeding hints follow: (1) Feed turtles in a container separate from their normal quarters and extra cleaning will be saved.

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Turtles and the Endangered Species Act In 1974, the Michigan Legislature passed the Endangered Species Act (Public Act Number 203) to provide legal protection, research, and wildlife species determined to be endangered management programs or threatened. At this writing, the eastern box turtle is listed as a threatened species in Michigan and afforded complete protection. The spiny softshell, the spotted turtle, and the wood turtle are listed as rare. Further study may show the need to move them to the endangered or threatened categories. This Act provides for a review of the every two years. The reader may contact the Michigan Department Natural Resources for additional information.

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Habitat Loss

Draining and filling wetlands, clearing woods, damming and channelizing streams, and other human activities, have reduced habitats for turtles. We need to aside areas of the natural environment, since both turtles and humans benefit from such activities.

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(2) Train turtles to eat bits of food from the end of a toothpick. It helps keep track of how much they eat and also helps keep the tank clean. (3) Feed baby turtles daily and adults two three times a week. (4) Remember aquatic turtles must eat with their heads under the water. (5) Do not put baby turtles in with large ones as they may be injured by the adults.

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Notes on Keeping Individual Species Musk Turtle. The basic set-up described previously is fine. Food meat, fish, worms, and insects. Snapping turtle. Small ones are easy to keep in the basic set-up, but large ones may be dangerous they were trained to take food from your hand when they were small. Food is meat and fish. Spotted Turtle. This form is so uncommon that should only be kept for scientific purposes. Wood turtle. This turtle is so uncommon it, too, should only be kept for scientific purposes. Eastern Box Turtle, It is against the law to keep this species. Map Turtle. This turtle is so difficult to maintain in captivity that it should only be kept for scientific purposes. Blanding’s Turtle. This turtle is too large for most set-ups. Little ones the basic set-up and fed meat, fish, and vegetables. may be kept Softshell. This turtle is so difficult to keep that it should only be kept for scientific purposes.

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Diseases A turtle kept in a clean, warm tank and given a well-balanced diet will usually be healthy and in turn will not be a disease risk to humans. The “‘Salmonella problem”? was the result of crowded and filthy conditions certain pet shops and/or improper handling after the turtles were purchased. Hands should be washed after handling turtles and tanks should not be cleaned near where food is prepared in a home. The most common disease pet turtles is malnutrition. Symtoms include a soft shell, puffy eyes, and tiredness and weakness. The cure is a more varied diet, extra vitamins, and warmth. Direct sunlight helpful. A turtle with whitish or grayish blotches skin or shell may have a fungus infection. Try adding table salt to the water (2 or 3 teaspoons per gallon) of the tank, and allowing the turtle to dry thoroughly in direct sunlight. Fungus and ‘‘itch’’ medication sold pet stores (for fish) may help cure fungus turtles. Turtles exposed to low temperatures or to sudden temperature changes may develop pneumonia. Symptoms include a runny nose and gasping

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with the mouth open. Warmth, extra vitamins, and proper use of antibiotics (prescribed by a veterinarian) may work, but a bad case of pneumonia usually fatal. If a captive turtle refuses to eat, or eats poorly, or does not seem to be is best to release it in a proper habitat before serious growing properly, health problems occur.

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References

W. J. 1955. Observations of the life history of the soft-shelled turtle, Trionyx ferox, with especial reference to growth.Copeia, pp. 5-9. Carr, A. F. 1952. Handbook of turtles. Ithaca, N.Y.: Comstock Publ. Assoc., 542 pp. CoNnanrT, R. 1975. A field guide to reptiles and amphibians of eastern and central North America. Boston: Houghton Mifflin Co., 429 pp. Ernst, C. H. and R. W. Barsovr. 1972. Turtles of the United States. Lexington: Univ. Press of Kentucky, 347 pp. EVERMANN, B. W. and H. W. Crark. 1916. The turtles and batrachians of the Lake Maxinkuckee region. Proc. Indiana Acad. Sci., pp. 472-518. GiBBons, J. W., 1967. Variation and growth rates three populations of the painted turtle, Chrysemys picta. Herpetologica 23:296-303. ———. 1968a. Reproductive potential, activity, and cycles the painted turtle, Chrysemys picta, Ecology 49:399-409. ———. 1968b. Growth rates of the common snapping turtle, Chelydra serpentina, ina polluted river. Herpetologica 24:266-267. GraHaM, E., 1970. Growth rate of the spotted turtle, Clemmys guttata, in southern Rhode Island. Jour. Herpetology 4:87-88. HOLMAN, A. 1967. The age of the turtle. Int. Turtle and Tortoise Soc. Jour. 1:15-21, 45. ———. 1969. The ancestral turtle. Int. Turtle and Tortoise Soc. Jour. 3:16-19. LAGLER, K. F. 1943. Food habits and economic relations of the turtles of Michigan with special reference to fish management. Amer. Midl. Nat. 29:257-312. RISLEY, P. L. 1933. Observations on the natural history of the common musk turtle, Sternotherus odoratus (Latreille). Pap. Michigan Acad. Sci. Arts, Lett. 17:685-711. ———. 1934. The activity of the coelomic (germinal) epithelium of the male musk turtle, Sternotherus odoratus (Latreille). Jour. Morphol.56:59-99. ———. 1938. Seasonal changes in the testes of the musk turtle, Sternotherus odoratus (Latreille). Jour. Morphol. 63:301-317. RUTHVEN, A. G., C. THompson, and H. T. GAIGE, 1928. The herpetology of Michigan. Mich. Handbook Ser. No. 3, Univ. Mich. 229 pp. BRECKENRIDGE,

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