Management regime influences shrubland birds and habitat conditions in the Northern Appalachians, USA

Population declines of birds that breed in early-successional shrubland habitat are of great concern to conservationists throughout the northeastern United States. To help increase the efficiency and effectiveness of efforts to conserve these species and their habitats, we studied birds in temporary forest openings created through even-aged timber harvest, and permanent wildlife openings maintained through mechanical treatment and prescribed burning in the Northern Appalachians, USA in 2010 and 2011. We assessed the effects of treatment method, time since last treatment, and retained tree cover on shrubland bird abundance and habitat conditions. Burned and mechanically treated wildlife openings differed only in grass and fern cover. Both types of wildlife openings had more grasses and forbs, and less bare ground than silvicultural openings. Six out of 8 focal bird species were less abundant in silvicultural openings than in wildlife openings. In contrast, abundance of only 1 species differed between burned and mechanically treated wildlife openings. Silvicultural openings supported the same species as wildlife openings, indicating that this management option could be used in place of more costly wildlife opening management. However, because birds were more abundant in wildlife openings, maintaining the current population size of shrubland birds under a management strategy based entirely on silviculture would require a 50-300% increase in the area of silvicultural openings, depending on the species. Individual species peaked in abundance at different times post treatment, indicating that managers must maintain a range of early-successional conditions across the landscape to provide habitat for the entire suite of shrubland birds. Six species exhibited a negative relationship with the basal area of retained conifer cover, and 7 species with deciduous tree cover, indicating that the retention of overstory trees in openings reduced their utility to early-successional birds.