Missouri Three-Toed Box Turtle
Photo by Nancy Smolak
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Missouri Three-Toed Box Turtle |
 Photo by Nancy Smolak
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.
 Photo by Nancy Smolak
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.
 Photo by Ruby Jung
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 it's 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.
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Copyright © 2002 Jim Jung |
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