Meeting Abstract
While Bergmann’s Rule (i.e., organisms are larger in cooler climates) applies to many organisms, it is not ubiquitous among ectotherms. Notably, Bergmann’s Rule does not apply to lungless terrestrial salamanders (genus Plethodon). Plethodon salamanders prefer cool microhabitats, but are physiologically and behaviorally limited by moisture and competition. As such, we were interested in whether moisture and competition outweigh the effects of temperature on body size. To determine the effects of abiotic (i.e., temperature and moisture) and biotic (i.e., intra- and inter-competition) variables on average adult body size, we performed repeated surveys of Plethodon species along an elevation gradient on Salt Pond Mountain, Virginia. We continuously recorded temperature and moisture and measured the body size of the most abundant species, Plethodon cinereus. Although competition for food and space is intense among Plethodon salamanders, moisture limits virtually all activity. Thus, we predict that moisture will be the greatest determinant of adult body size in Plethodon cinereus. By identifying the drivers of adult body size in natural populations, our results will contribute to ecogeography theory and the global understanding of species’ responses to climate change.
