Meeting Abstract
The impacts of climate change have been extensively studied in lizards. However, most studies have explored how warming may affect the potential for activity and subsequent growth and reproduction, while climate change may also affect overwintering lizards. In particular, although lizards may be able to begin activity and reproduction earlier under a warming climate, warmer winters will raise energy demands, increasing the risk of starvation and decreasing surplus energy for growth or reproduction. To better understand the energy demands of lizards during winter, we tested whether thermal acclimation of metabolism enables animals to save energy using a widespread group of lizards from the Sceloporus undulatus complex. In the lab, lizards from four populations were exposed to either a constant 12°C, a constant 2°C, or a linear decrease in temperature from 12°C to 2°C. After three weeks, we compared the metabolic rates of these when exposed to 2°C and 12°C to their rates prior to acclimation. Interestingly, lizards vary in their acclimation strategies based on their current climate. In particular, lizards from the relatively cooler populations (Colorado) reduced their metabolic rate only at the cooler temperature (2°C), and lizards from relatively warmer population (Arizona) reduced their metabolic rate only at the warmer temperature (12°C). Moreover, lizards from the population from New Jersey, which is characterized by an intermediate climate, reduced their metabolic rate under both 2°C and 12°C. These different levels of acclimation can affect the ability of lizards to mitigate impacts of global warming.
