Meeting Abstract
With temperatures rising globally, researchers are assessing the possible ramifications and impacts of the changing climate. Ectotherms are excellent indicators of potential climactic impacts because of their heavy reliance on the environment for their thermoregulation. Studies have historically looked at thermal maxima to establish predictive models for species extinctions. However, recent findings in marine invertebrates suggest that these thermal maxima, which have been considered as fixed variables, may in fact be plastic and dependent on the organism’s recent thermal history. If this is the case, then historical data, literature, and predictive models studying the effects of climate change may not be wholly accurate because so many are based on data from captive lizards that may be acclimated to laboratory conditions. Using a recently described methodology, we tested the critical thermal maximum of the Western fence lizard, Sceloporus occidentalis, in all four seasons, both under field and short (two-day) lab-acclimated conditions. We found that there were seasonal differences in each condition, but the differences were not the same between conditions. We also tested three acclimation temperatures during a single seven-day acclimation. The three acclimation temperatures (15C, 25C, and 35C) did not have a significant effect on the critical thermal maximum. However, when comparing thermal maxima, the seven-day acclimation condition had higher values than field condition lizards.
