Meeting Abstract
In vertebrate stress physiology, concentrations of glucocorticoid hormones such as corticosterone (CORT) are thought to increase when animals are exposed to stressful environments, facilitating an adaptive response to diverse stressors. However, we have limited understanding of how natural stressors, such as high temperature, affect the stress response of reptiles. We wanted to determine the corticosterone response to heat stress in the Eastern fence lizard, Sceloporus undulatus. Thirty-eight adult females were exposed to 42 °C for varying lengths of time, up to 3 hours. Plasma concentration of corticosterone was measured using EIA. As expected, plasma CORT concentration was higher in lizards exposed to high temperatures, with values similar to previously-recorded responses to other stressors. However, CORT concentration was not proportional to time spent at high temperature with CORT highly variable and plateauing at ~1h of heat exposure, and remaining high after 1 hour of recovery at room temperature. Additionally, movement to experimental chambers appears to have caused part of the observed elevation in CORT. Our results suggest that high-temperature induces CORT production in S. undulatus similar to other stressors, although the downstream consequences for performance or behavior are unclear.
