DETERMINING THE PREFERRED INTERNAL BODY TEMPERATURE OF PACIFIC RATTLESNAKES, CROTALUS OREGANUS.
James M. Whelan; California Polytechnic University, San Luis Obispo; 1 Grand Ave, San Luis Obispo, CA, 93405; (541) 727-1656; jawhelan@calpoly.edu; Hayley L. Crowell, Emily Taylor
Internal body temperatures of ectotherms are affected by their environment, size, sex, and food availability. In the wild, other factors may keep organisms from reaching their preferred internal body temperature such as predation, substrate, and refugia. Bearing this in mind, the trait may be plastic between populations. The way these factors affect Crotalus oreganus are unclear and we aimed to determine the preferred internal body temperature while taking these factors into account as well as determining whether or not there is a difference in preferred internal body temperatures between sites. To do this we implemented the use of a thermal gradient and a temperature logger to record internal body temperatures, in ten-minute intervals, of individual snakes from four separate field sites. Data was recorded for 12-hour periods in identical conditions. We expected to see snakes at coastal sites to have lower preferred internal body temperatures compared to inland snakes. We determined that there was no difference in the body temperatures across sites (p=0.18) with or without taking morphometrics into account. A factor that should be investigated next is how seasonality may change this outcome due to activity rates shifting throughout the year.
Poster Session   Student Paper