Meeting Abstract

P3.125  Saturday, Jan. 5  Perspectives of scale: the influence of body size, thermoregulation, and movement on the potential for interspecific interactions SMITH, J.J.*; SEARS, M.W.; Southern Illinois University; Southern Illinois University jjs1@siu.edu

The grain, or scale, that an individual organism experiences its thermal environment will largely be determined by its body size. Smaller organisms are more sensitive to thermal conditions than are larger organisms as a mere consequence of their mass. Because of this physical relationship, organisms of different sizes will not experience, or react to, thermal heterogeneity in quite the same way. Here, we illustrate how body size changes the perceived grain of the thermal environment, using simulations of animal movements constrained by thermoregulatory decisions through explicit spatial environments. Using this approach, we can show how potentially exploitable space changes across a day, as the environment warms and cools, for an individual of a given size. Further, we show the potential for interspecific interactions, especially when members of the interaction differ in body size, by predicting areas of spatio-temporal overlap of exploitable thermal habitats for the interacting species. Specifically, with respect to predation, our results suggest how spatio-temporal patterns of habitat use could be modified by prey to minimize the probability of encounter with a larger-sized predator; in response, a predator might choose suboptimal body temperatures to maximize the probability of encountering a prey. Spatially-explicit simulations of habitat use by interacting species (accounting for body size) will likely lead to novel testable predictions in nature that might not otherwise be expected from classical ecological theory.