UPPER THERMAL LIMITS IN THE EXOTIC GECKO HEMIDACTYLUS MABOUIA FROM FLORIDA

Abstract

As climate change continues to threaten biodiversity around the world, time is running out to protect many species from extinction. Lizards are among the most threatened species, and over twenty percent of all lizard species are expected to face extinction as temperatures increase globally. An open question is whether invasive species will suffer the same consequences of climate warming as endemic species. Hemidactylus mabouia, the Tropical House Gecko, is an exotic and highly abundant species of gecko in Florida and limited information is available on their thermal tolerance in the invaded range. We collected H. mabouia in Sarasota, Florida, where we measured critical thermal maximum (CT_max) by two commonly employed methods to determine the loss of normal function: pants and muscular spasms. We hypothesized that the two methods of measuring CT_max would produce similar results in H. mabouia. We found that the mean for CT_max (pant = 38.5 °C) was significantly different than the mean for CT_max (spasm = 41.9 °C). Hemidactylus mabouia had high CT_max estimates, higher than temperatures predicted from global warming. Based on these findings, climate warming is not likely to contribute to the population decline of H. mabouia in Florida in the near future, and there is a strong relationship between CT_max and method of measurement.