Hawk Mountain Winter Bird Population Study

Like the Breeding Bird Census, the Winter Bird Population Study (WBPS) is a monitoring program that estimates winter bird densities in specific habitat types throughout North America. In addition, the vegetation of the plot is described. Relatively large areas of a single habitat are preferred for WBPS plots. Censusing methodology follows the Cornell Laboratory of Ornithology guidelines. Two permanent plots (the same two used in our BBCs), a ridge-top south-southwest facing 19.3 ha site in 120-130 year old oak-maple forest (elevation 408-448m), and a low elevation east-facing 16.9 ha site in 120-200 year old, oak-maple forest (elevation 265-347m), have been gridded at 30.5 m intervals in the Sanctuary's forest. The two sites are 750m apart. The habitat in each plot is characterized on a Habitat Classification Form supplied by the Cornell Laboratory of Ornithology. A detailed vegetation survey and vegetation mapping of each plot was conducted in 1989 (F. Watson, unpubl. data).