The Swainson's warbler (Limnothlypis swainsonii Audubon) is a species of concern within forested wetlands across the southeastern U.S. Previous studies involving low-elevation sites may not have adequately represented the habitat affinities of this species. We examined relationships between Swainson's warbler occupancy and vegetation structure at relatively high-elevation bottomlands at White River National Wildlife Refuge (WRNWR). In 2004 and 2005, we systematically surveyed 1453 sites and collected vegetation data at 70 occupied sites ( 5% occupancy) and 106 randomly selected unoccupied sites. Occupied sites had greater canopy cover, density of cane (Arundinaria gigantea Walt. Chapm.) and shrub stems, litter depth, and greater and more uniform understory vegetation density than unoccupied sites. Moreover, cane and understory vegetation density were associated with more persistent habitat use. Ultimately, cane stem density was the best predictor of Swainson's warbler occupancy with an AIC(c) weight of 99% over all models considered. Overall, our results suggest that cane, dense understory structure, and a well-developed leaf-litter layer are key habitat components for Swainson's warblers at WRNWR. These findings are especially relevant given the substantial decline of canebrakes throughout the Southeast. Swainson's warbler management should include enhancement of canebrakes via manipulations that mimic natural disturbances.
|Original language||English (US)|
|State||Published - 2009|