The poet Ogden Nash touches some of our perplexity concerning turtles and tortoises with the following ditty:

The turtle lives ’tween fixed plates,

which practically conceal its sex.

Me thinks it clever of the turtle,

in such a fix to be so fertile.  

The topic for both this week and next week is that set of strategies that turtles use to overwinter and survive. Tortoises, e.g., the desert tortoise, are found, in North America, only in arid parts of our Southwest and northern Mexico. But we have two mostly terrestrial turtles species:  the ornate box turtle, found throughout Kansas; and the eastern box turtle, that reaches barley into extreme eastern and SE Kansas.

Box turtles really exemplify what Nash is describing. Both the front and back portions of the plastron (floor of shell) are hinged, and in a protective mode, the animal can fold both front and back upward to where they touch the carapace (roof of shell, highly domed in box turtles and tortoises) and completely hide legs, head and neck, and other soft parts behind bony plates.

Our beautiful ornate box turtle typically is active from late February until late December. To overwinter, it will burrow down into soft or sandy soil, in under a rotting log, or seek sanctuary in dens and burrows of other animals.

 Some turtles may secrete anti-freeze chemicals into their body fluids that increase freeze tolerance. Many years ago an Ohio biologist friend, who studied the eastern box turtle, found one “overwintering” with the back one-third of its body protruding out from the forest soil and litter. Ambient temperatures were such that the exposed portion must have been frozen. The researcher built a sturdy lattice-like structure around the animal to protect it from predators. Come early spring the turtle was gone, with no sign that any predator/prey interaction had occurred.