Neil Gifford
Wednesday, October 15, 2008 - 2:00-2:30
Shrubland birds of the northeastern U.S. are in steep decline and have become the most conservation-reliant avian group in the region. Their contemporary distribution is restricted to pine barrens, regenerating commercial forests, utility rights-of-way, and other types of managed early successional habitat. Most shrubland birds will use small and isolated patches, suggesting some level of resilience and area insensitivity, but will the birds avoid small and isolated patches burdened by severe threats like urbanization, fire suppression, and invasive plants? We tested whether shrubland birds associate preferentially with scarce and fragmented shrubland habitat in a threatened and intensively managed urban-wildland landscape, the 1,250 ha Albany Pine Bush Preserve, NY. During breeding season point counts in 2005 we observed 90 bird species, including 18 shrubland species, 12 of which have experienced significant long-term regional population declines, and ten species of greatest conservation need in New York State. Relative abundance for shrubland species was high. Two species previously thought to be extirpated from the preserve (pine warbler and eastern bluebird) were common. Community-level analysis of species-habitat relationships (i.e., habitat clustering with indicator species optimization) suggested that shrubland birds "preferred the limited shrubland habitat available in this landscape." We suggest 15 years of habitat management (e.g., prescribed fire, invasives management), combined with resilience and area insensitivity of shrubland birds, is offsetting the effects of fragmentation and habitat degradation in this rapidly urbanizing landscape. When managed appropriately, even small, isolated, and severely threatened shrublands may still provide attractive refuge for shrubland birds.
Keywords: SHRUBLAND BIRDS, EARLY SUCCESSIONAL HABITAT, PITCH PINE – SCRUB OAK BARRENS