Meeting Abstract
26.4 Friday, Jan. 4 Testing common models of temperature-dependent activity: implications for predicting responses to climate change. GUNDERSON, A.R.; Duke University arg12@duke.edu
Understanding behavioral responses to thermal variation is crucial for our attempts to predict the biological impacts of climate change. Several models have been proposed to explain the temperature-dependence of activity, usually with reference to the preferred temperature range (i.e., the temperatures organisms assume in a thermal gradient). I evaluated the agreement between observed activity of the Puerto Rican lizard Anolis cristatellus under natural conditions and three models of temperature-dependent activity with varying levels of thermal constraint. Activity rates and body temperatures of 299 A. cristatellus were measured in two habitat types: wet and dry forest. The data were then transformed according to the assumptions of the following behavioral models: Model 1- organisms are only active when body temperatures are within the preferred temperature range, Model 2- organisms are only active if body temperatures are below the upper bound of the preferred temperature range, and Model 3- body temperature does not affect activity within the activity window (i.e., if you are active, body temperature does not matter). I found that Model 1 provided a poor representation of A. cristatellus activity. However, the agreement between Models 2 & 3 and A. cristatellus activity depended on habitat type. Both models provided good representations of activity patterns in the wet forest but not in the dry forest. Thus, even among populations of a single species occupying the relatively small island of Puerto Rico, models did not perform equally well. These results illustrate the need for more fine-scale studies to inform the development of models that accurately reflect behavioral patterns seen in nature. More generally, our knowledge of the behavioral consequences of thermal variation is extremely limited, a problem that must be tackled in order to better understand the consequences of rising global temperatures.
