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Missouri Three-Toed Box Turtle
Terrapene carolina triungis
The Three-Toed Box Turtle Terrapene carolina triungis is the western woodland race (subspecies) of the Box Turtle clan. They differ from their eastern woodland relatives Terrapene carolina carolina by having only three toes on their hind feet instead of the normal four and by their drab shell colors they're olive-brown or horn-colored so they blend in well with a leaf littered forest floor. But usually even the most drably colored individual will betray its ancestry with faint (sometimes very faint) traces of patterning on the shell like their eastern relatives. This patterning is more pronounced in younger individuals and fades as the turtle grows older.
This branch of the box turtle clan was separated from its brethren during the last several ice ages our region has experienced and they weathered this climatic crisis in the southern Ozarks isolated from their eastern relatives. Here they developed independently and minor differences in shell color, shape and number of toes was accentuated and a new race evolved.
When the climate returned to "normal" (the climate we're familiar with today) they expanded their range south and east but were apparently unable to cross the upper Mississippi river. As a result woodland box turtles in Kentucky and Illinois look dramatically different from their near relations in Missouri and Arkansas (see photos). In addition to their shell color and lack of toe they differ slightly in diet being more herbivorous in adulthood than the eastern subspecies.
Another species of Box Turtle inhabits our area as well - the Ornate Box Turtle - Terrapene ornata (not pictured) that is found in the old prairie regions of Missouri and Illinois. It differs from the Eastern Box Turtle complex (group of subspecies) by its smaller size, slightly flatter shell, habitat preference, nearly carnivorous diet (it eats insects, snails and other medium to large arthropods) and by it's shell pattern which consists of thick, radiating yellow lines on each scute (large scale on the upper shell) as opposed to the yellow blotches of the eastern woodland race.
But in spite of these differences all three varieties share similar habits of courtship and reproduction they all lay their eggs in early summer for instance and have similar home range sizes. All three races can interbreed with one another.
Box Turtles are reputed to live for a hundred years or more. While this is remotely possible no box turtle reliably older than 35 years has ever been found in the wild. Specimens of the Eastern Box Turtle have lived as long as fifty years or more in captivity but these of course are protected from the usual vagaries of fate. The Three-Toed Box Turtle in the photos above is a large male and probably in his late twenties. While the Eastern Box Turtle pictured is a medium sized male probably in his early teens.
[Male and female box turtles can be distinguished by a number of traits. Males usually have slightly narrower shells than females, indented plastrons (the bottom shell), longer tails, longer front claws and red eyes.]
Box Turtles of all kinds are often taken home as "pets" where they're kept in basements for bug control or abandoned in an alien environment*. Neither of these options is good for the turtle since the vast majority of these poor unfortunates end up dying an untimely death. They're far better off left in their natural habitat where they were found.
* The Three-Toed Box Turtle in the pictures above was discovered in an Illinois interstate rest stop where he was trying to hitch a ride home to Missouri. After posing for these photos we found him a ride and he's now safely back home.
The information on this page is tailored to Southern Illinois, Southwest Indiana, Western Kentucky, and Southeast Missouri
Copyright © 2003 Jim Jung
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