NESTING SUCCESS OF YELLOW-BREASTED CHATS: EFFECTS OF NEST SITE AND TERRITORY VEGETATION STRUCTURE

Abstract

The effects of habitat and vegetation characteristics on the reproductive success of Yellow-breasted Chats (Icteria virens) were examined in central Kentucky. During the 1998 breeding season, 49 nests were located and monitored and the characteristics of nest sites and territories determined. Habitats where nests were located were categorized as old field, linear, or clump, and nests were classified as early or late. Chat nests were located in areas with more foliage and lateral cover than unused sites. However, most nests (55%) were not successful, and variables that differed between nest sites and random locations did not appear to influence nesting success. A diverse and, in an evolutionary sense, novel community of predators may eliminate predictably safe nest sites for chats on our study area. Chats in territories with more foliage cover and less canopy cover were more likely to fledge young. Dense foliage may lower the chances of nest predation by increasing the number of potential nest sites in a territory and may also provide better foraging habitat.