Eastern and Western Box Turtle Sex Identification, by Tess Cook


All North American box turtles belong in the Emydidae family of turtles, Terrapene. The family contains 4 species, T. carolina, T. ornata and the rarely seen T. nelsoni and T. coahuila. Terrapene carolina has 6 subspecies. All box turtles have a hinge (see picture on left by D. Senneke) on their bottom shell or plastron. The box turtles most commonly kept as pets are Terrapene carolina carolina, or the Common Eastern box turtle, the Three-toed box turtle, and the Gulf Coast box turtle. Three other box turtles in this group are rarely seen as pets because they have small ranges or are difficult to maintain. They are the Florida box turtles, the T. c. mexicana and the T. c. yucatana. The fourth species of box turtles, the Western Ornate, is often seen in the pet trade. For more information about the natural history of North American box turtles, please view the natural history web page.

The most common box turtles found in the pet trade or along road sides and fields are the Common Eastern, Three-toed, Gulf Coast and Western Ornate box turtles. They each have a distinctive look but some individuals are hard to identify, and everyone wants to know what sex their turtle is. This webpage will describe the differences in behaviors and physical traits of the sexes. Pictures will be used as much as possible to show the differences. However, sometimes the external, physical characteristics don't prove anything with certainty and the only thing to do is observe the turtle for a time and wait for internal signs to occur, like penis-fanning in males and egg laying for females.

T. c. carolina or Common Eastern: 4-6 inches long with a high, domed shell and a low, middorsal keel. The carapace is usually dark brown with orange or reddish blotches of various size and shape that form an attractive pattern. The plastron may or may not have dark areas around the scute margins. The skin of the turtle is brown and the males have colorful scales on the front legs. They are found from Maine to Georgia and westward to Michigan, Illinois and Tennessee.


T. c. triunguis or Three-toed: 3 1/2-5 inches long with a high-dome shell. The carapace is keeled and olive brown or yellowish brown and may or may not have markings of yellow . The markings are usually thin lines or spots and dashes. The plastron may or may not have dark areas. The skin is usually brown with yellow spots and the males have reddish heads with red, orange and black on the neck and forelegs. The beaks are also colorful. They usually have three toes on the hind feet but four toes are not uncommon. This subspecies may be found as far north as Missouri and southwards to Texas and Alabama.

T. c. major or the Gulf Coast: 5-7 inches long with a dome shell. The shell is olive brown or dark brown and there is very little marking. The back marginal scutes are often flared outward forming a slope or skirt. This adaptation may help them walk the marshy ground during the Gulf Coast’s wet season. The plastron is usually unmarked. The skin can be light or dark brown and the males have colorful necks and forelegs. They can have three toes or four toes and are found in Gulf Coast areas of Texas, Louisiana, Alabama and western Florida.

Terrapene ornata ornata or Western Ornate: 4-5 inches long with a flattened-dome shell and no central keel, although a yellow midline is not uncommon. The shell is dark brown or black with bright yellow lines that radiate to form a starburst pattern. The plastron is always marked with yellow and brown lines. The skin is dark gray and white and the head is dark brown with spots of white or yellow. The mature males obtain a greenish color on the top of the head. Ornate box turtles are found in grasslands of South Dakota through Illinois and southward to Arizona and Texas.

Florida box turtles are sometimes kept as pets. They are found only in Florida and are 5 to 5 1/2 inches long and look similar in coloration to the Western Ornate. However the carapace is a high dome and the yellow star burst patterns are thinner and more numerous. There are two thick, yellow stripes on each side of the head going from the corner of the eyes towards the neck. The plastron is cream color with fine lines of brown.


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Disclaimer: Please use all information contained on this web site at your own risk. Last updated on December 31, 2010 .