Nature Bulletin No. 7  March 24, 1945
Forest Preserve District of Cook County
Clayton F. Smith, President
Dr. David H. Thompson, Zoologist

****:SNAPPING TURTLES

A SNAPPING TURTLE, a BLANDING'S TURTLE and two 
PAINTED TURTLES were found along the shores of McGinnis Slough 
on March 10. They were alive but very sluggish. On March 17, nineteen 
snappers, another Blanding and several painted turtles were found alive. 
All were very sluggish although it was a warm, sunny day. The two 
largest snappers, weighing about 25 pounds each, later died. Numbers 
of dead painted turtles were found along the shore. This was unusually 
early for turtles to be out.

Turtles and frogs "hole up" for the winter and hibernate in the mud 
under the ice. When animals hibernate, their body processes do not stop 
completely; they merely slow way down. Some species slow down more 
than others but all of them continue to breathe or use oxygen, and their 
hearts continue to beat very slowly. Although turtles can remain under 
water for long periods in the hot summer, they have lungs and must 
come up to breathe air once in a while. So it is with frogs. Both turtles 
and frogs must have some oxygen when they hibernate for the winter 
under the ice. They get this oxygen by absorbing oxygen, dissolved in 
the water, through the membranes of their mouths and throats. Some 
kinds of animals may also take dissolved oxygen in through their skins.

When thousands of fish suffocate or "winter kill" due to thick, snow-
covered ice covering the water for a long time, as happened this winter, 
sometimes the turtles and frogs smother too. Since it was unusually 
early for turtles to be out we may suppose they were roused from their 
sleep by partial suffocation. Many floated to the top, got air, were 
washed ashore by the wind, and lived. Others died before they got 
ashore. The two big snappers were too weak to breathe and live.