Core vs Periphery Linking Environmental Variables and Stress with Amphibian Declines


Meeting Abstract

P3-137  Saturday, Jan. 7 15:30 – 17:30  Core vs. Periphery: Linking Environmental Variables and Stress with Amphibian Declines GOFF, CB*; GABOR, CR; WALLS, SC; Texas State University, San Marcos; Texas State University, San Marcos; US Geological Survey, Gainesville, FL goff@txstate.edu

Climate change has become a significant driver in ecology, and is associated with changes in environmental factors like temperature, humidity, precipitation, and sea level rise. In addition, anthropogenic disturbances also alter habitat and reduce habitat quality. These factors can limit population ranges with optimum habitat in the core of the range and lower quality habitat along the range periphery. One mechanism to assess how individuals and populations respond to changing conditions is to assess their physiological health. We obtained baseline and stress induced water-borne corticosterone (CORT) release rates for Pseudacris ornata (Ornate Chorus Frog) tadpoles from multiple sites in four locations across an east-west transect in northern Florida and one location in southern Georgia. We hypothesized that locations in the range periphery where populations have been declining would not show a stress response (indicating chronic stress) and that baseline CORT release rates from peripheral populations would differ from the more stable populations in the range core. We found that baseline CORT release rates were lower in core versus peripheral locations and that CORT release rates increased with lower water quality (higher water temp, tds, and conductivity). Higher baseline CORT in lower quality sites with lower water quality may partially mediate the observed population declines in peripheral populations.

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