. In particular, the introductions of predators (Relyea and Mills, 2001; Relyea, 2003; Relyea, 2005), pathogens (Parris and Cornelius, 2004), UV-B radiation (Kiesecker and Blaustein, 1995; Belden et al., 2003) and environmental contaminants (Carey et al., 1999; Newcomb Homan et al., 2003; Rohr et al., 2008; McMahon et al., 2011) have each been shown to increase stress in amphibians. Thus, changes in stress hormones in nature could cause similar changes in infection and result in increased host pathology, depending on timing and concentration relative to the experiments conducted here.
We thank J. Bowerman for collecting P. regilla, M. Venesky and J. Rohr for collecting H. cinerea and H. gratiosa, J. Hoverman and B. Carlson for collecting H. versicolor, and T. McDevitt-Galles, K. Richgels and D. Preston for collecting infected H. trivolvis. We thank L. Belden for her assistance with developing methods for the immune suppression experiment and D. Keeney and M. Redmond for their assistance in developing the fluorescent parasite labeling technique. We recognize T. Raffel and S. Paull for their contributions to data analysis. We gratefully acknowledge B. Hoye, J. Lambden and J. Jenkins for their help conducting experiments.
B.E.L. and P.T.J.J. contributed to the conception, design, execution and interpretation of the findings of this work. B.E.L. wrote the first draft of the manuscript and both authors provided subsequent editorial input.
This work was supported through funds from the US National Science Foundation [DEB-0841758, DEB-1149308, IOS-1121529] and the David and Lucile Packard Foundation.
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