A wealth of evidence suggests many animals behaviorally thermoregulate, but only one model exists to explain why some animals regulate precisely and other do so poorly. This simple cost-benefit model of thermoregulation does not seem to account for the diversity of thermoregulatory strategies observed among organisms. Likely, this model fails because it does not explicitly account for the spatial structure of the environment. The investigators will combine experimental and theoretical work to show that spatial structure has important consequences for the fitness cost of thermoregulation. They will independently manipulate environmental temperatures and environmental patchiness to test predictions about thermoregulation in outdoor enclosures. Fence lizards (Sceloporus undulatus) are expected to adjust their body temperatures according to both the statistical and the spatial distributions of environmental temperatures. This experiment will provide one of the strongest experimental tests of the cost-benefit model of thermoregulation. The investigators will also develop a spatially-explicit model of thermoregulation that enables researchers to predict behavior in natural environments, where predators, competitors and prey covary with thermal resources. The model will consist of computer simulations to explore both the thermal preferences and the movement patterns that evolve in particular environments. The researchers will ultimately be able to apply their model using thermal maps of natural environments, produced by artificial neural networks. The project will provide a vastly improved test of the current theory of thermoregulation, and expand theory by explicitly including costs of thermoregulation that arise from spatial structure. The new theory will enable researchers to predict behavioral strategies in complex environments, which include spatial structure and biotic interactions. The project will also make significant contributions to the missions of research and education at Indiana State University, Southern Illinois University, and beyond. First, the project will support the training of students who are members of under-represented groups at both undergraduate and graduate levels. Second, the project will enhance education and outreach opportunities for high school teachers. Third, the project will foster cross-institutional workshops on computer modeling of physiological and behavioral ecology, which will provide formal opportunities for interaction among graduate students and faculty.