Meeting Abstract

P2-154  Sunday, Jan. 5  Are Introduced Species More Plastic? A Comparison of the Heat-Hardening Capacity of Native and Non-Native Anolis Lizards DEERY, SW*; HARO, D; GUNDERSON, A; Tulane University; Tulane University; Tulane University sdeery@tulane.edu

An important negative anthropogenic effect on the natural environment is the introduction of invasive species. One hypothesis to explain invasive species’ success is that they have high levels of phenotypic plasticity, allowing them to adjust to new environments quickly and outcompete native species. Our study focused on heat hardening, a form of physiological plasticity defined as a short-term increase in heat tolerance as a result of exposure to high temperatures. We tested for differences in heat hardening ability in two species of lizard in the greater New Orleans area: the native Anolis carolinensis and the invasive A. sagrei, which is native to Cuba. To ascertain the magnitude and timing of heat hardening, we measured an initial critical thermal maximum value (CT_max) and then re-tested each lizard after either 2, 4 or 24 hours. We found that the native A. carolinensis undergoes significant heat hardening, especially at the 2 and 4 hour intervals. In contrast, the invasive A. sagrei does not undergo any heat hardening. Our results do not support the hypothesis that invasive species have greater phenotypic plasticity than sympatric native species. However, the results do suggest that the native species may be better able to adjust to warming than the invasive species in this system.