Meeting Abstract
Relative to higher latitude species, tropical ectotherms are thought to be thermal specialists and therefore especially vulnerable to anthropogenic climate change. Nevertheless, most tropical species live in closed forests which promote thermoconformity. Thermoconforming species experience the full range of temporal thermal variation in their habitat, while species in higher latitude, heterogeneous habitats can thermoregulate to achieve narrow body temperature distributions. Thus, while ectotherms living in higher latitudes experience greater annual and diel variation in temperature, they may be thermal specialists relative to tropical forest species. We studied the thermal ecology and physiology of two closely-related species occupying divergent thermal environments: Anolis sagrei lives in open habitat in The Bahamas and Anolis apletophallus occurs in densely vegetated tropical forest in Panama. We evaluated the extent to which thermoregulatory strategy (thermoconformity versus thermoregulation) was associated with specialization in thermal physiology, and then modeled the effects of climate change on each of these species while explicitly taking behavior into account. We hypothesized that A. sagrei in open, thermally heterogeneous habitats may have narrower breadths for physiological performance compared to A. apletophallus in the temporally stable tropics, due to differences in thermal opportunity, which may reduce future performance under predicted warming scenarios. We discuss the importance of considering thermoregulatory strategies when predicting the fitness consequences of climate change on ectotherms across latitudes.
