Meeting Abstract
Color polymorphism is the presence of two or more discrete, genetically determined color morphs in a population. In many cases, the ecological and evolutionary dynamics maintaining polymorphisms are not well understood. One hypothesis is that polymorphism is maintained by interactions with visual predators, either by way of apostatic selection, or by being differentially camouflaged in different microhabitats or seasons. In general, organisms that better blend into their background have an increased chance of survival. The Eastern Red-backed Salamander, Plethodon cinereus, contains two common color morphs, a striped morph and an unstriped morph. Presently, it is not known which of these two morphs is more cryptic, or if the answer to this question is context dependent. To address this question, we are studying three populations in Ohio: a monomorphic striped population, a monomorphic unstriped population, and a polymorphic population. For this study, we gathered information on whether the two morphs differ in their relative camouflage across seasons, light conditions, and habitats. A spectrometer was used to collect reflectance measurements from color patches, providing measures of brightness, hue and chroma. Ambient light from each location and from different times of the day was also measured, as the quality of available light impacts perceived color. We are running this data through mathematical models of the avian and mammal visual system to quantify how well each morph blends into the background. Overall, this study will provide essential data for better understanding the adaptive basis of the polymorphism, and what evolutionary and ecological dynamics might be involved in its maintenance.
