The Foraging and Nesting Ecology of Black-Throated Blue Warbler (Dendroica Caerulescens) and Hooded Warbler (Wilsonia Citrina) in the Southern Appalachians

Abstract

Some species of Neotropical-Nearctic migrant birds have been showing declines in populations for the past thirty years. Black-throated Blue Warbler ( in the southern Appalachians. This research documents the foraging and nesting habitat use and nest fate of these two species primarily in cove forests at elevations of 2800-3200 ft. Two cove forests were delineated: acidic cove hardwood and rich cove hardwood. I conducted foraging observations randomly while searching for nests. I also collected structural and floristic vegetation data to relate foraging, nest-site selection, and nest fate to habitat..There was no difference in nest success for either species between forest types. Both species readily utilized rhododendron as a nesting substrate but was lowest for nests initiated mid-season (0.9472 &#177; 0.009 and 0.9519 &#177; 0.012, respectively) as opposed to early (0.9664 &#177; 0.008 and 0.9652 &#177; 0.009, respectively) or late (0.9708 &#177; 0.006 and 0.9862 &#177; 0.006, respectively) in the season.Both species selected nest sites with high cover of low shrubs and small disturbances. However, nests in rhododendron (t = 3.58, df = 56, p < 0.05) and over all (t = 6.89, df = 122, p < 0.001). Nest fate was dependent on cover 1 m above the nest for both species. These results highlight the subtle differences in the ecology of similar species that may allow for species coexistence. Additionally, small changes in management can potentially affect similar species differently. High nest success of in the southern Appalachians indicates that these forests may indeed be source populations. Future research should be directed towards mortality during other times in these species' annual cycle.