Indirect Effects of Gypsy Moth Defoliation on Nest Predation

Abstract

Large areas of forested land are altered each year from gypsy moth (Lymantria dispar) larvae feeding. Little is knovrn about the impacts of forest defoliation on populations or reproductive success of forest-dwelling birds. Therefore, we investigated the effects of defoliation by gypsy moth larvae on the vulnerability of artificial bird nests to predation. We placed 450 nests along transects in a West Virginia oakhickory (Quercus/Carya spp.) forest that had received variable defoliation for 3 years. Nests placed in defoliated sites suffered a bigher predation rate (41.6%) than did those in nondefoliated sites (22.7%, P = 0.001). Nests placed ≤1 m from the ground suffered higher predation than those placed >1 m (46.4 vs. 21.7%, P < 0.001)