American Box Turtle

Common box turtles are predominantly terrestrial reptiles that are often seen early in the day, or after rain, when they emerge from the shelter of rotting leaves, logs, or a mammal burrow to forage. These turtles have an incredibly varied diet of animal and plant matter, including earthworms, slugs, insects, wild berries (2), and sometimes even animal carrion (4). In the warmer summer months, common box turtles are more likely to be seen near the edges of swamps or marshlands (2), possibly in an effort to stay cool. If common box turtles do become too hot, (when their body temperature rises to around 32° centigrade), they smear saliva over their legs and head; as the saliva evaporates it leaves them comfortably cooler. Similarly, the turtle may urinate on its hind limbs to cool the body parts it is unable to cover with saliva (5). Courtship in the common box turtle, which usually takes place in spring, begins with a 'circling, biting and shoving' phase. These acts are carried out by the male on the female (4). Following some pushing and shell-biting, the male grips the back of the female's shell with his hind feet to enable him to lean back, slightly beyond the vertical, and mate with the female (6). Remarkably, female common box turtles can store sperm for up to four years after mating (4), and thus do not need to mate each year (6). In May, June or July, females normally lay a clutch of 1 to 11 eggs into a flask-shaped nest excavated in a patch of sandy or loamy soil. After 70 to 80 days of incubation, the eggs hatch, and the small hatchlings emerge from the nest in late summer. In the northern parts of its range, the common box turtle may enter hibernation in October or November. They burrow into loose soil, sand, vegetable matter, or mud at the bottom of streams and pools, or they may use a mammal burrow, and will remain in their chosen shelter until the cold winter has passed (4).

The common box turtle is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in this species should be carefully monitored to ensure it is compatible with the species' survival (3). In addition, many U.S. states now regulate or prohibit the taking of this species (4).

This turtle gets its common name from the structure of its shell which consists of a high domed carapace (upper shell), and large, hinged plastron (lower shell) which allows the turtle to close the shell, sealing its vulnerable head and limbs safely within an impregnable box (2). The carapace is brown, often adorned with a variable pattern of orange or yellow lines, spots, bars or blotches. The plastron is dark brown and may be uniformly coloured, or show darker blotches or smudges. The common box turtle has a small to moderately sized head and a distinctive hooked upper jaw (4). The majority of adult male common box turtles have red irises, while those of the female are yellowish-brown. Males also differ from females by possessing shorter, stockier and more curved claws on their hind feet, and longer and thicker tails. There are six living subspecies of the common box turtle, each differing slightly in appearance, namely in the colour and patterning of the carapace, and the possession of either three or four toes on each hind foot. The subspecies Terrapene carolina triunguis is particularly distinctive as most males have a bright red head (4).

The common box turtle inhabits open woodlands, marshy meadows, floodplains, scrub forest and brushy grasslands (2) (4).

The common box turtle occurs in the eastern United States and eastern Mexico, where it is distributed from Maine and Michigan to eastern Texas and south Florida, and south to the Mexican states of Yucatán and Quintana Roo. T. c. mexicana (Mexican box turtle) and T. c. yucatana (Yucatán box turtle) occur in Mexico. The other four subspecies, T. c. carolina (eastern box turtle), T. c. major (Gulf Coast box turtle), T. c. bauri (Florida box turtle) and T. c. triunguis (three-toed box turtle)are found in the United States (4).

Classified as Lower Risk / Near Threatened (LR/nt) on the IUCN Red List 2007 (1), and listed on Appendix II of CITES (3).

While not yet considered by the IUCN to be globally threatened (1), many populations of the common box turtle have been reduced or eliminated by habitat destruction caused by agricultural and urban development. Development brings with it an additional threat in the form of increased infrastructure, as common box turtles are frequently killed on roads and highways. Collection for the international pet trade may also impact populations in some areas (4) (7). The life history characteristics of the common box turtle, (long lifespan and slow reproductive rate) (4), make it particularly vulnerable to such threats.