Modeling Overwintering Survival of Declining Landbirds: The 2004-05 Annual Report of the Monitoring Avian Winter Survival (MAWS) Program on four DoD Installations in Southeastern United States

Long-term data from the North American Breeding Bird Survey BBS indicate that many temperate-wintering landbird species, including many sparrows and other species that prefer early successional stage habitats, are experiencing highly significant continent-wide population declines. Recent results from the Monitoring Avian Productivity and Survivorship MAPS Program suggest that low survival, rather than low breeding productivity, may be the proximate demographic cause of population decline for many migratory landbird species. Additional evidence from the scientific literature suggests that habitat loss and degradation on these species wintering grounds may decrease their overwintering survival rate andor their physical condition at the end of the winter season, which, in turn, may cause increased mortality on spring migration and lowered productivity on the breeding grounds. Spatially extensive data on habitat- and age-specific overwintering survival rates and late-winter physical condition are urgently needed to formulate, implement, and evaluate effective management plans to enhance and preserve winter habitat so as to reverse the population trends of declining species and maintain stable or increasing populations. The Department of Defense may be able to play an important role in such efforts, because the creation and maintenance of the early successional stage habitat required by many of these declining species may be very compatible with management efforts to enhance military Readiness and Range Sustainment.