Meeting Abstract

P3-139   -   Cool chameleons can’t change critical limits Goodman, CM; Claunch, NM*; Kluever, BM; Romagosa, CM; University of South Florida; University of Florida; USDA Wildlife Services National Wildlife Research Center; University of Florida nmclaunch@ufl.edu

Acclimatization to new environmental thermal regimes may influence the success and spread of species. In Florida, cold temperatures primarily limit the distribution of non-native ectotherms, but acclimation or adaptation to cool temperatures may facilitate expansion of these species. We sought to determine the acclimatization potential of panther chameleons, Furcifer pardalis, by exposing them to naturally-occurring environmental conditions through four seasons in North Central Florida at the USDA Wildlife Services National Wildlife Research Center, Florida Field Station. We collected chameleons from an established population at the northern extent of their known established range in Florida, about 150 km south of the experimental exclosure site. During fall, winter, and summer we examined locomotor performance at five body temperatures, critical thermal minimum, gaping threshold at high temperatures, and thermal preference in an arena with a thermal gradient. During post-winter trials, chameleons presented with dermal lesions, which were determined to be Paranannizziopsis australasiensis, and underwent a course of antifungal treatment for three months leading to suspension of spring trials. Though we observed temperature-dependent thermal performance, chameleons maintained similar performance, critical thermal limits, and thermal preferences across seasons, despite long-term exposure to cool temperatures and fungal infection in winter. This indicates that thermal acclimatization may not be a factor in the establishment success of the source population examined, and that the locomotor performance of F. pardalis may not shift in response to exposure to changing thermal regimes. These data can be applied to mechanistic species distribution models to predict potential locations of establishment for F. pardalis.