Habitat preference and population density among wintering Hermit Thrushes in SE GeorgiaPresented during Species Distribution Modeling Roundtable, AGM of the AAG (2009)
AbstractMany migratory species of birds use SE Georgia during the nonbreeding season. However, different bird species favor different habitats and exhibit a wide range of occupation densities. Over the 2007-2008 winter we attempted to establish occupation preferences and the nonbreeding density of hermit thrushes in SE Georgia. Previous research in SE Georgia indicated very low densities of wintering hermit thrushes in prime wet hardwood sites (i.e., wet swamps) whereas personal experience suggested quite the opposite. Using tape-playback calls we conducted a non-random survey of 'human landscapes' along dirt road transects throughout Bulloch County. Surveys were conducted at both dry and wet culverts that intersected hardwood forests, pine plantations, and/or agricultural land. At each survey location, we collected GPs coordinates and identified vegetation immediately adjacent to the road. At each survey point location tape-recorded hermit thrush songs were played and the number of birds that responded to the playback were recorded. Because the roads and culverts were spatially imbedded in a mosaic of 'human landscapes' clusters of point counts occurred. Although spatially biased these clusters are scattered across Bulloch County. Spatial analysis of these data using a 200 ft sound buffer (this is we assume the distance that tape-playback calls might be heard) in ArcGIS indicates that hermit thrushes in SE Georgia winter in far higher densities than previously recorded and occur in their greatest densities 1.387 birds per acre in both hardwood forest and pine plantations adjacent to the Ogeechee River in the NE of the county.
- Hermit thrush,
- Nonbreeding habitats,
Citation InformationMark R. Welford. "Habitat preference and population density among wintering Hermit Thrushes in SE Georgia" Presented during Species Distribution Modeling Roundtable, AGM of the AAG. Las Vegas, NV. Jan. 2009.