THERMAL TOLERANCE OF AMPHIBIANS FOUND IN PRIMARY AND SECONDARY FORESTS OF LA SELVA, COSTA RICA
Elva Manquera1, Steven Whitfield2.
1Oregon State University, Corvallis, OR, 2Zoo Miami, Miami, FL.
Amphibians globally are currently one of the most threatened vertebrate groups. These threats range from pollution and habitat loss to emerging infectious diseases and global warming. To better understand how global warming affects amphibians, we examined the maximum temperature at which amphibians can function (critical thermal maximum, or CTmax). Our focal organisms were 4 rainforest frog species found at La Selva Biological Station in Costa Rica: Eleutherodactylus brandsfordii, Oophaga pumilio, Craugastor megacephalus, and Craugastor mimus. We hypothesized that the CTmax would be higher for populations found in secondary forests than for populations found in primary forests, because the forest types vary in the amount of sunlight and differ in vegetation. Specimens were collected in both forest types and, following capture, the substrate (forest floor) temperature was measured with an infrared temperature gun. In the lab, each individual was placed on its back in a gradually heating water bath, and the temperature at which it could not right itself was recorded as CTmax. Our data showed no significant difference in CTmax between populations found in primary and secondary forests with a p-value of 0.1503, but there was significant findings between CTmax and species with a p-value of 1.449e-07. The substrate temperature had no significant difference between primary and secondary forests, with a p-value of 0.8123.This suggests that amphibian species will react differently to climate change, but it also suggests that amphibians will be effected the same amount in both primary and secondary forests.