Nest-site selection and productivity of the acadian flycatcher (Empidonax virescens) in the southwestern Appalachian Mountains of Virginia

I studied the nest-site selection of the Acadian Flycatcher (Empidonax virescens) in the George Washington National Forest of southwestern Virginia from early May through July 1996 and 1997. Data were collected from nine 30 ha study plots. I measured habitat features at 37 Acadian Flycatcher nests and compared them to 30 nonuse sites randomly selected within the vegetation types associated with nests. Because Acadian Flycatchers have a strong riparian habitat association for nest-site selection, nonuse sites were established along riparian corridors not occupied by nesting flycatchers. Data also were collected to determine relationships between microhabitat characteristics and nesting success of the Acadian Flycatcher. Nest-sites were associated with a more mature or climax community, as evident from the high percentage (75%) of nests in eastern hemlock (Tsuga canadensis), a climax community tree species and the greater basal area found at nest-sites over nonuse sites. Nest-sites also had lower small stem density and ground cover than nonuse sites. Nest-sites were always found near streams, although I found no conclusive evidence that any stream characteristic influenced nest-site selection. Habitat features did not differ between successful and depredated nests. Brood parasitism by Brown-headed Cowbirds (Molothrus ater) was not a major factor in the reproductive success of Acadian Flycatchers (only a 2% parasitism rate); depredation accounted for the majority of nest failures. These results suggest that silviculture activities near riparian corridors could drastically reduce habitat availability and subsequently contribute to population declines of the Acadian Flycatcher. Future research should focus on determining the size of riparian buffer strips needed to retain this species along riparian corridors in the Appalachian Mountains. This strategy can be applied to the current downtown revitalization efforts by the City of Muncie. The ideas and general theories can also be applied by small Indiana towns which suffer from economic problems. A comprehensive plan that is tailored specifically for a downtown which account for the organization, design, economic, and promotion needs of downtown will set the course for successful commercial revitalization.Department of BiologyThesis (M.S.