Executive Summary- Golden-winged Warbler (Vermivora chrysoptera) Status Assessment and Conservation Plan
The Golden-winged Warbler (Vermivora chrysoptera) is an early-successional species that requires a somewhat unique habitat of sparse trees and shrubs with an herbaceous understory of grasses and forbs in either upland or wetland settings. Golden-wing populations are declining throughout all of their range as early-successional habitats revert to forest and as upland and wetland habitats are lost to human development. These declines are resulting in extirpation of the species from areas that have supported Golden-winged Warblers for at least the last century (Georgia, South Carolina, Virginia, Massachusetts, Connecticut, Rhode Island, Vermont, New Hampshire, Indiana, Illinois, Ohio). Based on Breeding Bird Survey (BBS) data, populations have declined, on average, 2.4% per year survey-wide (P < 0.01; n = 269 routes) and have declined, on average, 3.4% per year in the United States (P < 0.01; n = 239 routes) over the last 37 years of monitoring (1966-2003; Sauer et al. 2004).
Golden-winged Warblers show stable or increasing populations over the entire BBS monitoring period (1966-2003) in the Boreal-Hardwood Transition region and neighboring Ontario. However, analyses of the last 10 years of BBS data (1994-2003) show an annual decline of 9.0% in U. S. Fish and Wildlife Service Region 3 (north-central states of Minnesota, Wisconsin, and Michigan), an 11.3% decline annually in Ontario, and a 20.4% decline in Region 5 (northeastern states). Region 4 populations (southeastern states) are so low that estimating recent population trends is problematic (-1.7%/year, P = 0.74, but only 4 routes remaining with Golden-winged Warblers). Although the northern range once seemed to provide a refuge for Golden-winged Warblers, analyses of recent population trends suggest a very rapid rate of decline in the northern portion of the range as well as long-term decline in the southern portion.
Causes for the declinesinclude principally habitat loss from maturation of fields and other early-successional habitats into forest, loss of wetlands, and loss of habitat to human development. Loss of quality stopover and wintering habitat may also be contributing to declines. In addition, a generally warming climate may be pushing Golden-winged Warblers northward and into higher elevations, with Blue-winged Warblers (Vermivora pinus) filling in the gaps. The exact relationship between Golden-winged and Blue-winged warblers remains unclear (correlation versus causation). In the Northeast, Golden-wing-Blue-wing interactions including hybridization appear to be related to the disappearance of Golden-wings. In other parts of the range, especially in the Southeast, this does not seem to be the case- Golden-winged Warblers have declined in absence of Blue-wings and significant levels of hybridization.
Without significant conservation attention, population declines are likely to continue resulting in extirpation of the species from an extensive portion of its range. Golden-winged Warbler populations are in danger of becoming disjunct, with a relatively large but declining population (1000s of breeding pairs) in Wisconsin, Minnesota, and Ontario, and another, much smaller, fragmented population (100s of breeding pairs) centered in the Appalachians from Georgia-North Carolina-Tennessee to New York. Golden-wings have been identified as a national Bird of Management Concern by USFWS. In addition, Golden-wings are listed as a high-priority species in bird conservation plans in most of the Bird Conservation Regions (BCRs) in which they occur. These actions to date, however, have resulted in little specific on-the-ground management to address the habitat loss issue.
Research on Golden-winged Warblers needs to focus on understanding under what habitat conditions Golden-winged Warbler populations can persist (with and without Blue-wings). Management prescriptions, then, should be developed that will perpetuate these habitats on public and private lands. Opportunities to manage for viable populations of Golden-winged Warblers need to be identified, including areas where the perceived threat from interactions with Blue-winged Warblers is currently minimal, such as at higher elevations in the southern Appalachians or in northern populations occupying wetland habitats. Additional effort is needed to document winter distribution, along with detailed studies of winter ecology, habitat use, and survival rates, and to document factors limiting over-winter survival. Finally, more research is needed to substantiate climate change hypotheses for this particular species independent of land-use change.
Buehler, D. A., J. L. Confer, R. A. Canterbury, T. C. Will, W. C. Hunter, R. Dettmers, and D. Demarest. 2006. Status Assessment and Conservation Plan for the Golden-winged Warbler, Vermivora chrysoptera, in the United States. U. S. Department of the Interior, Fish and Wildlife Service Biological Technical Publication FWS/BTP-R6XXX-2006, Washington, D.C.