Katherine Whitehead
Biology 301 Lab
7/15/13
Abstract
Thermoregulation is necessary for ectotherms to survive. One important mechanism for thermoregulation seen in turtles is the ability to migrate between land and water habitats. This mechanism was studied using I-button data loggers placed inside marshmallow peeps to record temperatures in two different microhabitats; one in a stream and the other on the bank adjacent to the stream. Five samples were placed in each microhabitat and temperature was recorded every minute for 20 minutes. It was hypothesized that turtles in moving waters, such as streams, would exhibit lower body temperatures than those residing on banks alongside streams due to convection of the moving water. The results of this experiment indicated a significant difference between body temperatures of the model turtles in each microhabitat. The temperatures of the samples in the stream were significantly lower than those of the samples on the bank. These results indicate that the convection from the moving stream waters provide effective means for lowering body temperature in ectotherms and, therefore, can be a critical behavioral adaptation for turtles inhabiting areas with warmer climates.
Introduction
Body temperature is a characteristic that is crucial to an organism’s survival. It affects numerous biological processes in organisms including growth, metabolism, reproduction, and performance (Fitzgerald et al. 2006). In endothermic organisms, body temperature is regulated by metabolism. However, in ectothermic organisms, such as turtles, body temperature is not maintained by metabolism; instead they must rely on the thermal environment surrounding them to regulate their body temperature. The mechanisms most responsible for body temperature changes in ectotherms include radiation, conduction, convection, and evaporation. Radiation is the gain or loss