Point count surveys in order to gain density estimates of birds

Recent evidence suggests that the southern Appalachian Mountains are experiencing increasing spatial and temporal variability in hydroclimate. Specifically, the region is experiencing both increasing frequency of extreme precipitation and a reduced frequency of more moderate precipitation. Moreover, heterogeneity in precipitation among subwatersheds has resulted in neighboring watersheds experiencing large differences in precipitation levels over the past 30 years. This extreme spatial variability creates an opportunity to examine how differences in precipitation relate to the abundances of regional flora or fauna. Breeding bird abundance was measured on areas of intact forest in Macon County, North Carolina, USA that have varied in precipitation over the past 30 years. I hypothesized that long term changes in moisture regimes would cause terrestrial vertebrates to persist in an area where their species specific environmental requirements were being met. Focal passerines of this study have variable life history traits and therefore I hypothesized that vegetation that promotes their respective habitat would be a main factor determining their abundance; furthermore, vegetation is proximally associated with precipitation, therefore some measurable differences among sites may exist. All dry sites in this study have higher estimated avian densities, Black-throated Blue Warblers were found exclusively on dry sites and Black-throated Green Warblers were found almost exclusively on wet sites. These results suggest that a correlation exist between microclimate and avifauna surveyed in this study.