Meeting Abstract
Reptiles have become focal organisms for studying the direct effects of changing climates due to their reliance on environmental temperatures for physiological functions. In this study, we compared thermal and behavioral data collected during 2010-2017 from four distinct populations of Crotalus oreganus on the central coast of California to examine how climate change will impact closely related populations inhabiting distinctly different climates. Using biophysical temperature models, surgically implanted temperature data loggers, and radiotelemetry, we collected data on the thermal microhabitats available as well as field active body temperatures for 85 individual snakes. Along with lab-derived preferred body temperature range, we determined the thermal accuracy of each snake population. Snakes from hot, inland populations thermoregulated most accurately, despite inhabiting more thermally constrained environments. We then used a climate change model at a 1°C and a 2°C increase to predict changes in habitat thermal quality and theoretical changes in snake standard metabolic rates. In both coastal and inland areas, the availability of annual thermally favorable temperatures is predicted to increase with increasing ambient temperatures. Additionally, a theoretical increase in body temperature of 1 and 2 °C would have a minute impact on the overall energetic needs of snakes, still allowing them to meet baseline energetic requirements with only one large meal a year. Small increases in ambient temperature will most likely have little impact on rattlesnake thermal ecology, as our findings suggest that these animals are fairly precise thermoregulators, maintaining relatively constant body temperatures regardless of extreme thermal variation in their surrounding habitats.
