Body temperature influences growth rates of Common Gartersnakes (Thamnophis sirtalis)

Abstract

Habitat selection can have large impacts on animal fitness. Temperature is an important aspect of habitat suitability for ectotherms, and temperature differences between habitats can thus lead to fitness differences. Here, we use an experiment with female Common Gartersnakes (Thamnophis sirtalis) to examine the effect of body temperature on change in mass (i.e., growth rate), which is a component of fitness. We placed female gartersnakes in experimental enclosures in old field and in forest and monitored their body temperature and mass throughout the summer. Gartersnakes in old field were warmer than gartersnakes in forest, warmer gartersnakes were more likely to eat earthworms, and warmer gartersnakes gained more mass. We therefore provide evidence that habitat use influences body temperature, and body temperature then influences growth, a component of fitness.