Climate change is a direct threat to Pennsylvania’s amphibians because, as ectotherms,
they are physiologically and behaviorally dependent on temperature (Corn, 2005).
Temperature has dramatic effects on the physiology, ecology, and behavior of
amphibian larvae (reviewed in Ultsch et al. 1992). For example, temperature is inversely
related to time to metamorphosis and body size at metamorphosis. These two
parameters are also directly affected by larval density (competition) and the presence of
predators (reviewed in Alford 1992). Climate change is predicted to have significant
effects on temperature and precipitation in Pennsylvania (Wilson and Mitchell 1987,
Wetherald and Manabe 1988, Hansen et al. 1988, Mitchell et al. 1995, Laprise et al.
1998), and is likely to drive changes in amphibian behavior and stress responses in the
Commonwealth. If we can predict how climate change will alter amphibian behavior and
stress responses then we will be more likely to detect climate change-driven responses
through behavioral observations during population monitoring activities.