Effects of soil type on body condition of an endemic and a widespread woodland salamander

One of the central questions in ecology is why some species are common and others are rare. Eastern Redback salamanders (Plethodon cinereus) are one of the most common vertebrates in North America. In contrast, Big Levels Salamanders (Plethodon sherando) have one of the smallest ranges on any vertebrate in North America. Based on USGS soil maps, the range of Big Levels salamanders largely corresponds to an unusual soil type with low organic content, low pH, and high levels of some minerals (e.g. manganese). These soils are quite sandy and support an unusual plant community rather than the mature, deciduous forest in which salamanders are typically found. We hypothesize that Big Levels salamanders are specifically adapted to this soil type and will maintain higher body condition on their own soil type as compared to surrounding soil types, and similarly that Redback Salamanders will maintain higher body condition on their own soil type as compared to the Big Levels soil type. We will test this by measuring change in body condition (residuals of regression of body mass on SVL and tail length) of both species of salamanders in field enclosures containing one salamander of each species and either soil that is characteristic of Big Levels or soil from more typical areas where Eastern Redbacks are found.