Although predators can deter an animal from regulating its body temperature by basking or shuttling, this response to predation should depend on the spatial distribution of thermal resources.

By simulating predation risk, we showed that movement, thermoregulation, and corticosterone of male lizards (Sceloporus jarrovi) depended on the spatial distribution of shade.

Simulated risk caused lizards to move less, thermoregulate worse, and circulate more corticosterone than they did without risk. However, a patchier distribution of shade enabled lizards to move more, thermoregulate better, and circulate less corticosterone when exposed to a simulated predator.

In the absence of simulated risk, lizards in patchier environments moved less, thermoregulated better, and circulated less corticosterone, indicating the distribution of shade also affected the energetic cost of thermoregulation.

This study provides the first test of a spatial theory of thermoregulation under the perceived risk of predation.

All data were collected and stored using Microsof Excel, and all data were processed (i.e., statistical analyses) using R.

Microsoft Excel