Comparative Thermal Ecology of Coastal and Inland Populations of Southern Pacific Rattlesnakes (Crot

Crowell, Hayley L.

Taylor, Emily

Biological Sciences Department

California Polytechnic State University

San Luis Obispo CA 94307 USA

Understanding the effects of changing temperature regimes on a species is crucial if land managers and researchers are to make informed decisions about how to mitigate the predicted loss of diversity as a result of anthropogenic climate change. Field active body temperature data can be used to estimate metabolic rates using equations established in laboratory studies. The goal of this analysis is to use historical body temperature data from four distinct populations of Crotalus helleri from central California (two inland and two coastal) to compare body temperatures, estimated metabolic rates and annual energy budgets across varying habitat types. Snake body temperature data were collected via internal implantation of Thermochron iButton temperature loggers from 2006 to 2016. Our data show that snakes at inland sites experience higher body temperatures and therefore greater energy expenditure than coastal populations. Operative temperature models will be used in combination with predicted increases in ambient temperature to extrapolate probable changes in body temperatures, activity times, and energy budgets at each site by 2100.