There's something about Box Turtles that makes a person smile. Perhaps it's because they're so different from most animals as they wander the woods, homeless but also carrying all the shelter they'll ever need. Or maybe its because this is a creature that can pull in its head, legs, and tail and close up its shell, withdrawing completely from the outside world.
We frequently encounter Eastern Box Turtles (Terrapene carolina) on trails at Hilton Pond Center, and some individuals are easily recognized by their unique appearances. Most have shells with chips or scratches that are evidence of some mysterious incident from long ago; a straight two-inch shell gash on one lucky-to-still-be-alive turtle probably was caused by a mower blade. Each Box Turtle also has distinctive markings on its upper shell, or carapace. Often these are wide splotches of orange (right), but sometimes the markings are fine star bursts of yellow that contrast sharply against a dull brown background.
Not only are individual turtles identifiable, but we can even determine the sex of each in one of three ways. A side view of the female's carapace shows it is squared off at the back (left), while a male has a sloped carapace; the angular shape of the female's shell provides room inside where eggs can develop. Box Turtle plastrons (bottom shells) also show sexual differences. The male's plaston has a shallow central depression into which the female's carapace fits when he mounts her from the rear to mate, while a female's plastron is undimpled--again allowing added space for eggs. The final clue to a Box Turtle's sex is its eye color; males have irises with at least some bright red color (below left), while females have yellow, orange, or brown eyes.
Most of our local Box Turtles continue to nibble on mushrooms or blackberries when we pass, but a few are so skittish they always withdraw at least part way into their shells. This is facilitated by a plastron that has a cartilaginous hinge (above right). In particularly good blackberry years, Box Turtles go into a slow-motion feeding frenzy and gorge themselves so heavily they can't close their shells completely. This doesn't seem like good survival strategy, but we'll bet the well-fed turtles with blackberry-stained faces or fat rolls around their legs could care less--and that's another thing about Box Turtles that makes people smile.
All photos © Hilton Pond Center
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