Are Low Nest Temperatures Related to Hatchling Painted Turtle Mortality During Hibernation?

The body temperature of ectothermic ( cold-blooded ) animals is closely linked with the temperature of the surrounding environment. Many ectotherms living in cold regions behaviorally avoid freezing temperatures by seeking hibernation sites that do not freeze. Some ectotherms are unable to do so and have evolved physiological mechanisms for surviving sub-zero temperatures. We are measuring the lethal limits of freezing in hatchling painted turtles in the field. Painted turtle females lay eggs in a terrestrial nest near the water in early summer. These eggs hatch in August or September. However, the hatchling turtles remain in the mother\u27s nest, only a few centimeters under the soil’s surface, until the following spring. Consequently, these turtles are exposed to freezing Midwestern winter temperatures while they are still in the nest. By monitoring natural painted turtle nests, we will examine the relationship between nest temperature during hibernation, and hatchling survival in the nest. We hypothesize that nests experiencing temperatures below -8 C will have substantial mortality