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City Limits: Heat Tolerance Is Influenced By Body Size And Hydration State In An Urban Ant Community, Dustin Jerald Johnson

University of the Pacific Theses and Dissertations

Cities are rapidly expanding, and global warming is intensified in urban environments due to the urban heat island effect. Therefore, urban animals may be particularly susceptible to warming associated with ongoing climate change. Thus, I used a comparative and manipulative approach to test three related hypotheses about the determinants of heat tolerance or critical thermal maximum (CTmax) in urban ants—specifically, that (1) body size, (2) hydration status, and (3) preferred micro-environments influence CTmax. I further tested a fourth hypothesis that native species are particularly physiologically vulnerable in urban environments. I manipulated water access and determined CTmax for 11 species common …