2006 BES Annual Meeting Presentation and Poster Abstracts
The Effect of Residential Properties on Breeding Bird Diversity in Urban Forest Patches
Co-Authors: Mary L. Cadenasso, Gary W. Barrett
Abstract: Urban forest patches function as habitat fragments within a landscape matrix dominated by human development. The utility of a forest fragment as bird habitat is determined by local- and landscape-scale variables; both internal patch features and landscape matrix characteristics influence avian habitat selection. In residential areas, management of properties surrounding forest patches augments the abundance of resources available to forest birds. Breeding bird communities in 15 small forest fragments (2-8 ha) in the Gwynns Falls Watershed, Baltimore, Maryland were surveyed during the 2005 breeding season. An information-theoretic approach was used to select models that best explain avian community structure in these patches. Alternative models included different subsets of variables describing the forest patch and the surrounding residential matrix. Models were compared to assess if variables describing the matrix explained variation in forest patch bird communities beyond what could be explained by forest patch characteristics. Matrix variables included neighborhood age, land-cover composition, and the density of bird resource subsidies (feeders, baths, and nest boxes) within 100 m of the forest edge. Bird species richness was greater in forest patches with high-levels of coarse vegetation (tree and shrub) cover within the 100 m buffer, which tends to occur in intermediate-aged neighborhoods. Tree cover within the buffer explained more variation in Neotropical migrant species richness than the area of the forest patch itself. These relationships were observed within a narrow buffer width, indicating that individual land-owners can manage their property to enhance avian diversity in adjacent forest patches.