Eastern Box Turtle (Terrapene carolina): Facts and Lifespan

What does an eastern box turtle look like?

The upper shell, or carapace, is high and domed, a little like an upturned bowl. It is usually brown or nearly black with a highly variable pattern of yellow or orange lines, spots and blotches, so no two turtles look exactly alike. Young turtles have a low ridge, or keel, along the middle of the back that smooths out with age. Against the forest floor the pattern breaks up the outline of the shell and makes a resting turtle surprisingly hard to spot among fallen leaves.

The lower shell, or plastron, is brown to tan, sometimes with darker smudges. Its key feature is a flexible hinge across the middle. When the turtle is threatened, it pulls in its head, legs and tail and lifts both halves of the plastron against the carapace, sealing itself inside a bony box. The page Can box turtles close their shells? explains how the hinge works.

The skin is dark brown or black with yellow, orange or red spots and streaks, brightest on the head and front legs. The upper jaw ends in a sharp, slightly hooked beak. The feet are only slightly webbed, and the eastern box turtle normally has four toes on each hind foot, which helps tell it from the three-toed box turtle of the Mississippi Valley.

Males and females are easy to tell apart. Most males have bright red eyes, while most females have yellowish-brown or brown eyes. Males also have a concave (dented) rear plastron that helps them stay balanced on a female’s shell when mating, longer and thicker tails, and short, thick, curved claws on the hind feet.

How big do eastern box turtles get?

Eastern box turtles are small. Adults usually have a shell about 13–15 cm (5–6 in) long, and the full range is about 11–20 cm (4.5–8 in). Most adults weigh roughly 300–500 g (11–18 oz), less than a typical can of soup. Males are slightly larger on average than females.

Box turtles grow fastest in their first years, at about 1.5 cm (0.6 in) of shell length a year, then slow down sharply once they mature. Growth can continue very slowly for decades.

Taxonomy: eastern box turtle or common box turtle?

The names can be confusing. Terrapene carolina is the species, often called the common box turtle. The eastern box turtle is its most widespread subspecies, T. c. carolina, the one first described by Carl Linnaeus in 1758. Other subspecies include the Gulf Coast box turtle (T. c. major), the largest form, the three-toed box turtle (T. c. triunguis) and the Florida box turtle (T. c. bauri), plus two forms in Mexico. Some herpetologists now treat several of these as separate species, so lists differ between sources.

Despite living on land, box turtles are not tortoises. They belong to Emydidae, the family of pond turtles and sliders, and their closest relatives include Blanding’s turtle and the European pond turtle. The comparison turtle vs tortoise explains what separates the two groups.

Habitat and range

The eastern box turtle lives in the eastern United States, from southern Maine and the southern parts of Michigan south to northern Florida, and west to eastern Kansas, Oklahoma and Texas. It was once found in southern Ontario but has disappeared from Canada. In the north it rarely lives above about 300 m (1,000 ft), while in the southern Appalachians it occurs up to about 1,800 m (6,000 ft).

Its favorite habitat is deciduous or mixed forest with a moist, well-drained floor of leaf litter. It also uses forest edges, old fields, pastures, marshy meadows and stream banks, especially in summer. Studies in good hardwood forest have found several adults per acre, but numbers are much lower where roads and housing break up the woods.

Each turtle keeps to a small home range, often less than 230 m (750 ft) across, and may stay in the same patch of woods for decades. Moved turtles try hard to walk back home. More detail is in Where do box turtles live?

What do eastern box turtles eat?

Eastern box turtles are opportunistic omnivores. In the wild they eat earthworms, slugs, snails, beetles, caterpillars and other insects, as well as berries, fallen fruit, flowers, leaves, roots and mushrooms. They also eat carrion, including dead amphibians, birds and small mammals, and occasionally catch a frog or salamander.

Diet changes with age. Young turtles are mostly carnivorous, because animal food fuels fast growth, while adults eat a larger share of plants and fungi. Box turtles are fond of mushrooms, including some that are poisonous to people, and they help spread the seeds of the wild fruits they eat, such as mayapple and blackberries.

Because a box turtle is cold-blooded, its appetite depends on temperature rather than a fixed need for calories. In cool or dry weather it can simply stop feeding and wait in a shelter until conditions improve.

Behavior and daily life

Box turtles are active by day. In summer they forage mostly in the morning and after rain, when slugs and worms come to the surface. On hot afternoons they hide under logs, in mammal burrows, in shallow scrapes called forms, or soak in puddles, mud and shallow streams. When body temperature climbs to around 32 °C (90 °F), they may smear saliva on their head and legs to cool off by evaporation.

They are not territorial. Home ranges of different turtles overlap, and males sometimes spar by shoving and biting at each other’s shells, but serious fights are rare. A box turtle walks steadily with its head held high and may cover around 50 m (55 yd) in a typical day, although longer trips happen in the breeding season.

In the north of the range, box turtles enter a winter dormancy called brumation in October or November. They dig as deep as about 60 cm (2 ft) into loose soil, leaf litter, stump holes or the mud of a stream bank and stay there until April. Southern turtles may stay active through most of the winter. The page Do turtles hibernate? covers how they survive the cold.

Reproduction and life cycle

Mating can happen from spring to fall. Courtship has three stages: the male circles, bites and shoves the female, then climbs onto her shell, and finally leans back almost vertically to mate. A female can store sperm and lay fertile eggs for up to four years after a single mating.

Most nesting takes place in May to July. The female digs a flask-shaped hole in sandy or loamy soil with her hind feet, often at dusk, and lays usually 3 to 8 white, leathery eggs, each about 3 cm (1.2 in) long. She covers the nest and leaves. The eggs hatch after about 50 to 90 days, depending on soil temperature, and hatchlings either emerge in late summer or stay in the nest through the winter.

Like many turtles, box turtles have temperature-dependent sex determination. Nests at about 22–27 °C (72–81 °F) produce mostly males, while warmer nests above about 28 °C (82 °F) produce mostly females. Most eggs and hatchlings are eaten by predators, and maturity is reached at about 5 to 10 years, so a female needs many years of nesting to replace herself.

How long do eastern box turtles live?

Eastern box turtles are among the longest-lived reptiles in North America. The Smithsonian’s National Zoo gives a typical lifespan of 25 to 35 years, and long-term field studies have followed marked wild adults for 50 years or more. Reports of box turtles over 100 years old exist, and one often-cited record is about 138 years, but very old ages are hard to prove because nobody knows exactly when a wild turtle hatched.

Counting the growth rings on the shell gives a rough age for young turtles only; once growth slows, the rings become too thin to count. The question How long do turtles live? compares box turtles with sea turtles and giant tortoises.

Predators and threats

Raccoons, skunks, foxes, crows and snakes raid nests and eat hatchlings, whose shells stay soft for several years. Adults are well protected by their closing shell, though raccoons and dogs sometimes chew them and wildfires can kill turtles sheltering in leaf litter.

Most of the real threats come from people. Woodland is cleared and broken into small patches by farms and housing. Roads are especially deadly, because turtles cross them slowly and many are killed by cars, mostly adult females looking for nest sites. Lawn mowers and farm machinery also kill box turtles. Each year thousands are taken from the wild, either for the pet trade or by people who pick up a turtle “to save it” and carry it away from the home range it knows. Diseases such as ranavirus have caused local die-offs.

Conservation status

The IUCN Red List classifies Terrapene carolina as Vulnerable. In its 2011 assessment, the IUCN cited a widespread, persistent and gradual decline that probably exceeds 32 percent over three generations, and moved the species up from Near Threatened. The population trend is decreasing.

The species is listed on Appendix II of CITES, which controls international trade, and many states restrict or ban collecting it. Because box turtles mature late, lay few eggs and depend on high adult survival, even a small rise in adult deaths, for example from one busy road, can push a local population into slow decline. Box turtles are still fairly common in parts of the South but are scarce or listed as species of concern in several northern and Midwestern states.

Myths and facts

Myth: box turtles can leave their shell. False. The shell is part of the skeleton, fused to the ribs and backbone, so a turtle can never crawl out of it.

Myth: you can tell a box turtle’s exact age by counting its shell rings. Only roughly, and only in young turtles. Rings can form more than once a year and wear away on old shells.

Myth: a turtle found far from water is lost. Not for box turtles. They are land turtles that live in woods and fields, and a turtle moved to a “better” place usually tries to walk back and may die on the way.

Relationship with people

The eastern box turtle is the official state reptile of North Carolina and Tennessee, and it is one of the most familiar wild animals in eastern backyards and parks. Many people meet one crossing a road. If it is safe to do so, wildlife agencies advise moving the turtle across in the direction it was heading and leaving it there, rather than taking it home or relocating it. The best way to help box turtles is to keep woods, hedgerows and meadows connected and to slow down on country roads after summer rain.