License to chill: Behavioral responses of mammals to extreme temperatures.
Mille T Elsborg
As climate warms, the increased frequency of extreme temperature days poses behavioral challenges to mammals. In this study, we investigated how mammal behavior changes in response to extreme hot temperatures. Specifically, we hypothesized that extreme temperatures would result in lower overall activity and a lower proportion of activity during the hottest part of the day. Additionally, we hypothesized that mammals would seek thermal refuge in forested habitats with increased canopy cover. Lastly, we anticipated greater behavioral changes for large than small animals as heat dissipation effectiveness scales inversely with animal size. To examine the effects of extreme temperatures on mammal behavior, we collected observations of mammals using motion-activated trail cameras at six sites in Upstate South Carolina. At each site, three to six cameras were placed in habitats classified as forest, edge, or open. For each observation, we recorded the species present and time of day. We classified each species as either small, medium, or large based on their weight. Extreme temperature days were defined as those having a maximum temperature in the highest 10% of temperatures recorded during all days at that site. We compared habitat, time of activity, and overall activity levels between extreme temperature days and other days for all mammals and for each size category. As hypothesized, mammals were less active overall on extreme temperature days. However, they did not avoid the hottest part of the day. Further, only small mammals used forests as a thermal refuge on hot days. In conclusion, results suggest that mammals do change behavior in response to extreme temperatures. However, the need for heat dissipation does not seem to be of more importance than other characteristics such as diel activity patterns and habitat choice as a predictor of mammal responses to extreme temperatures.
Mille T Elsborg is a junior student athlete from Denmark majoring in biology and minoring in psychology. Her achievements include being a member of Tri Beta Honor Society and giving a poster presentation at the annual Association of Southeastern Biologists conference. She hopes to obtain a masters in the US within the field of marine science.