Meeting Abstract

P2.51  Sunday, Jan. 5 15:30  Abiotic constraints on tropical lizard abundance LOGAN, ML; Dartmouth College michael.l.logan@dartmouth.edu

Most models aimed at predicting the response of biological populations to climate change consider only the effects of increasing temperature. At present, the vast majority of studies ignore other abiotic variables, despite their potential to affect the physiological performance, activity time, and population growth of many species. In addition to temperature, both precipitation and wind patterns are projected to change over the coming century in many parts of the globe. Here, I explore how daily variation in the thermal, hydric, and convective (wind) environments affect the abundance of two species of Anolis lizard from the Bay Islands of Honduras. One species, A. lemurinus, is a forest species, whereas A. allisoni is found in open habitat. For both species, individuals were most likely to be active when their operative thermal environments provided temperatures close to their optimum for sprinting. However, when wind speed was high, A. allisoni remained inactive, even when the thermal environment was optimal. Our data suggest that cutaneous water loss from exposure to convection may create a trade-off between the ability of open habitat lizards to achieve optimal body temperatures through basking and their ability to maintain water balance. Our results highlight the need to consider other factors besides temperature when constructing predictive models for the biological impacts of climate change.