Meeting Abstract
Predicting how organisms will be affected by climate change is a complex challenge. Ectotherms, particularly lizards, are model systems for climate change impacts because their physiology and behavior are highly dependent on environmental temperatures. Lizards may be buffered from some effects of climate change due to their ability to behaviorally thermoregulate. It is generally assumed that behavioral thermoregulation is a phenotypically plastic trait, but determining whether between-population differences in thermoregulation are due to plasticity or local adaptation has been hampered by the difficulty of measuring thermoregulation in wild lizards in natural habitat, particularly when they are sheltered or otherwise difficult to observe. We used light-level data recorders to continuously record thermoregulatory behavior in cool, high-elevation and warm, low-elevation populations of desert short-horned lizards. We then reciprocally transplanted lizards and continued to record their thermoregulatory behavior when in a novel environment. In comparison to their thermoregulatory behavior at their home site, high-elevation lizards transplanted downslope spent more time buried in the substrate and less time basking in full sun, whereas low-elevation lizards transplanted upslope spent less time in shelters and more time basking in full sun. Our study demonstrates empirically that thermoregulation is a behaviorally plastic trait that can be adjusted immediately in response to novel environmental conditions. Further, we present a method for continuously recording thermoregulatory behavior in wild reptiles in their natural habitat.
