Meeting Abstract
As a null model, increased rates of activity should lead to increased rates of growth in ectotherms. A previous study in sagebrush lizards (Sceloporus graciosus) showed that, despite increasing potentials for activity, lizards at lower elevations grew more slowly. In that study, estimates of potential activity were spatially-implicit; yet, a recent model of behavioral thermoregulation suggests that the spatial heterogeneity of operative temperatures influences thermoregulatory performance—and thus activity—as much as temperature itself. Here, I use a spatially-explicit model of thermoregulation to predict potential activity for populations of sagebrush lizards along an elevational range. Dynamic thermal landscapes were created by coupling climatic and geospatial data with a biophysical model that predicts operative temperatures. An individual-based model of thermally-constrained animal movement was used to estimate potential activity and energetic expenditure in these landscapes. Further, a dynamic energy budget model was coupled with the individual based model to estimate potential growth for lizards across their lifetime. Here, I show that, although longer times are available for activity at lower elevation, spatial arrangements of microhabitats restrict activity and influence energetics leading to patterns of growth.
