Blue-winged Warbler
Vermivora pinus

Migratory Status: Neotropical migrant

PIF Population Estimate: 390 000

Percent of western hemisphere population breeding in boreal forest: <25%

BAM Effective Detection Radius (m) : 57.2

PIF Maximum Detection Distance (m) : 100

Canadian BBS Population trend: 8.4 n.s. (-5.6 to 22.4)

Life History

The Blue-winged Warbler is a brilliant yellow songbird, common to shrubby or overgrown fields of the northeastern region of the United States. It is well-known by conservationists and birders for its interaction with its sister species, the Golden-winged Warbler (V. chrysoptera). Where the two species overlap on the breeding grounds, they freely hybridize, resulting in two frequently observed hybrid forms, the “Brewster’s” and “Lawrence’s” Warblers that are intermediate in appearance between the two parent species. The interaction between the two species is of some concern for the conservation of Golden-winged Warblers, because Blue-winged Warblers are continuing to expand their range, and in most cases Golden-winged populations have disappeared within 50 years of initial contact with Blue-winged Warblers.

Males in breeding plumage are bright yellow overall, with a black eye-line, an olive tinge to their nape and back, and a blue-gray colour to their tail and wings feathers. They also have two distinct white wing-bars. Females in breeding plumage are similar to males, but have duller colouration, with less pronounced wing-bars, a gray eye-line, and an olive crown. Blue- and Golden-winged Warbler hybrids are intermediate in appearance between the two species, with the “Brewster’s” hybrid resembling the Golden-winged Warbler with the facial pattern of a Blue-winged Warbler, and the “Lawrence’s” hybrid having the body plumage of a Blue-winged Warbler but with the facial pattern of a Golden-winged Warbler. Male Blue-winged Warblers sing high-pitched, buzzy songs. Hybrids learn either the Golden-winged or Blue-winged Warbler song types, not an intermediate of the two.

European settlement in North America likely benefitted Blue-winged Warbler populations by increasing the amount of early successional and shrubby habitats, which has allowed this species to steadily expand its range north and eastward. The breeding range of Blue-winged Warblers currently extends from the central Midwest in the United Sates eastward to the coast and northward into southern Ontario. During the non-breeding season, this Neotropical migrant can be found in secondary forests and edge habitats in humid and semi-humid regions of Mexico, southward to Panama. They are also rare inhabitants in the Caribbean, and may be recent winter residents in Bermuda.

Blue-winged Warblers are insectivorous, foraging in the upper canopy of trees, in shrubs, and on the ground in dense vegetation. They eat a variety of insects, such as crickets, moths, larvae, and spiders, and will probe leaves, hang upside down on branches, and glean food off twigs and bark to capture their prey.

Reference(s)

Gill, F. B., R. A. Canterbury, and J. L. Confer. 2001. Blue-winged Warbler (Vermivora pinus), The Birds of North America Online, . A. Poole, Ed. Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North America Online database: http://bna.birds.cornell.edu/bna/species/584

Vallender, R., V. L. Friesen, and R. J. Robertson. 2007. Paternity and performance of golden-winged warblers (Vermivora chrysoptera) and golden-winged X blue-winged warbler (V. pinus) hybrids at the leading edge of a hybrid zone, Behavioral Ecology and Sociobiology, 61:1797-1807.