Ontogeny and Feeding Ecology of the Red-Backed Salamander, Plethodon cinereus

Abstract

I determined whether variation in diet related to variation in head and/or body size and whether ontogenetic size change was associated with dietary shifts in the terrestrial red-backed salamander, Plethodon cinereus. No ontogenetic shift was found in the diet of P. cinereus, nor was there an apparent relationship between head size and prey size in larger salamanders. However, prey size was related to juvenile head size, indicating that overall body size constrains prey selection in small individuals. Juvenile P. cinereus have proportionally broader heads than adults, indicating an ontogenetic change in head shape. I hypothesize that head shape is attained by a heterochronic change in development that enables hatchlings to utilize a wide range of prey-i.e., broad head shape in small salamanders is a mechanism for generalized feeding. I also suggest that terrestrial salamanders may exhibit combinations of ontogenetic changes in head morphology and diet.