Amphibian and Small Mammal Assemblages in a Northern Virginia Forest Before and After Defoliation by Gypsy Moths (Lymantria dispar)

Abstract

The introduced European gypsy moth (Lymantria dispar) caused substantial defoliation and mortality of oak trees along the North Fork of Quantico Creek in Prince William Forest Park, Prince William County, Virginia, U.S.A., in 1989 and the early 1990s. Results of a drift fence/pitfall study conducted in 1988 were compared to those obtained from the same technique in the same areas in 1993 to elucidate whether the amphibian and small mammal assemblages had changed over time. Number of Lithobates sylvaticus increased significantly in 1993, but the numbers of Lithobates clamitans and Plethodon cinereus were significantly higher in 1988. Total numbers of amphibians caught in both years was similar. Two species of salamanders caught in 1988 were not caught in 1993, and one salamander and one frog caught in 1993 were absent in 1988. Total numbers of small mammals caught in 1993 were significantly greater than in 1988. The increase was due to greater numbers of Blarina brevicauda and Sorex longirostris. The hypothesis that no significant differences in amphibian and small mammal species richness and relative abundance before and after gypsy moth defoliation hypothesis was not supported by the results of this study.