Influence of intraspecific density and cover on home range of a plethodontid salamander

Abstract

Hypotheses about the influence of intraspecific density and available cover on home range size (=mean activity radius) of a plethodontid salamander (Desmognathus monticola) were tested by field experimentation from June 1980 to October 1981. A second order mountain stream in southwestern North Carolina was marked into five sections (two control and three experimental) and three replicated treatments were performed: Treatment I, low and high density additions of D. monticola; Treatment II, addition of cover objects (rocks); Treatment III, addition of cover and D. monticola. In Treatment I, home ranges of D. monticola on high density addition plots increased significantly relative to those on control and low density addition plots. Mean stomach content biomass and number of prey items of salamanders from high density plots were less than controls in all comparisons throughout the experiment but only one comparison revealed a statistically significant difference. Mean stomach contents of salamanders from low density plots were less than controls in 60% of all comparisons and only one statistically significant difference was found. Home range size was not affected significantly by Treatments II and III. Results of these experiments suggest that home range size of D. monticola may vary as a function of the number of conspecifics and cover objects; i.e., when the number of D. monticola increases where cover is limited, home range size increases.