NEST-SITE SELECTION BY HOODED WARBLERS IN BOTTOMLAND HARDWOODS OF SOUTH-CAROLINA

We measured habitat features at 45 nests of Hooded Warblers (Wilsonia citrina) and 45 non-use sites in bottomland hardwood habitats in the c oastal plain of South Carolina during the breeding seasons 1993-1994 t o determine features that affect nesting success. Hooded Warblers nest ed in switchcane (Arundinaria gigantea) and hardwood saplings or shrub s that averaged 1.76 +/- 0.10 m (SE) in height. Nests were more concea led from above (P = 0.001) and from the side (P = 0.002) than surrogat e nests placed at nonuse sites but were less concealed from below (P = 0.002). Nest sites also had a greater number of potential substrates (P = 0.014) in the nest patch (5-m radius) and greater measures of veg etation density (P < 0.05) in the nest patch than non-use sites. Succe ssful nests differed from unsuccessful nests only in the amount of fer n cover in the nest patch (greater for successful nests, P = 0.012). F ern cover may influence nesting success through an effect on behaviora l defense strategies. Nesting success of Hooded Warblers may largely b e unrelated to fine-scale differences in vegetative characteristics of the nest site.