Abstract

Understanding ecophysiological/bioenergetic responses to elevated temperatures is vital to assessing future impacts on amphibian health and demographics. There is, however, a dearth of data concerning thermal influences on the energetics of larval amphibians, including measures of respiration rates which underlie other bioenergetic processes. We therefore measured respiration rates across a range of temperatures (18.3–30°C) in wild-caught larval Cope's Gray Tree Frog (Hyla chrysoscelis), a species widespread throughout the eastern and southeastern United States. Temperature and body size significantly affected respiration rates in a linear fashion. The Q₁₀ calculated across the range of exposure temperatures was 1.72 for absolute respiration rates (mg O₂/min) and 1.76 for mass-adjusted rates (mg O₂/g min), suggesting less than a doubling of respiration rates over a 10°C increase in temperature. Our data, when considered with the limited data for other amphibians, suggest there are substantial species-specific differences in respiration/bioenergetics. Such ecophysiological information is vital to future considerations of amphibian energy budgets in light of the changing global climate.