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Golden-winged Warbler (Vermivora chrysoptera)

The Golden-winged Warbler is one of North America's most beautiful yet enigmatic songbirds. It also is more abundant in Wisconsin and Minnesota than anywhere in the world, making it one of our region's highest conservation priorities. Populations of Golden-winged Warblers have declined 2.5% per year since 1966, for reasons that are not completely understood. One of the likely causes involves the Blue-winged Warbler, which hybridizes with Golden-winged Warblers to produce "Brewster's" and "Lawrence's" Warblers. The hybrid offspring share characteristics of both species. Brewster's hybrids have the white breasts of the Golden-winged Warbler and the thin eye stripe and white wing bars of the Blue-winged Warbler. The Lawrence's hybrid is produced by interbreeding of Brewster's with Blue-wings and is much rarer and more variable in appearance, although it usually has the face mask of the Golden-winged Warbler (a recessive trait) and the yellow breast of the Blue-winged Warbler. During recent years, Blue-winged Warblers have extended their range northward, leading to higher rates of hybridization and more direct contact with the Golden-winged Warbler. Blue-winged warblers are thought to dominate when they and Golden-winged Warblers compete for the same food and nesting resources. Blue-winged Warblers, however, are not as dependent on shrub habitats for breeding and might be less impacted by shrub habitat loss. Hybrids between the two species are less successful and have only a 50% probability of successfully raising offspring compared to the 90% success rate of purebred pairs.

Several other factors, including urbanization and reforestation of farmland, nest parasitism by Brown-headed Cowbirds, and deforestation of tropical overwintering habitats, have been implicated as causes of the decline. As Blue-winged warblers increase their range north and west it is likely that populations of pure Golden-winged Warblers will continue to disappear. The impact of the Blue-winged Warbler certainly is exacerbated by the decline in favorable habitat. In order to help save the Golden-winged Warbler from extinction, a number of studies throughout the Golden-winged Warblers' range have been initiated to document numbers of both species and their hybrids.

For information on Golden-winged Warbler Atlas project see http://birds.cornell.edu/gowap/why.html

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Last updated on April 15, 2014