Respiration Rates of Larval Cope's Gray Tree Frogs (Hyla chrysoscelis) Across a Range in Temperatures

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 degrees 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 Q(10) calculated across the range of exposure temperatures was 1.72 for absolute respiration rates (mg O-2/min) and 1.76 for mass-adjusted rates (mg O-2/g min), suggesting less than a doubling of respiration rates over a 10 degrees 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.