Monday, 23 February 2015

B.O.T.D. Blue-Winged Warbler

B.O.T.D. Feb 23, 2015

Blue-Winged Warbler (Vermivora pinus)

The scientific name may be Vermivora pinus, but evidently the blue-winged warbler does not read Latin, because it has no connection with pine woods at all. Second-growth woodlands and overgrown fields afford a natural home for this bird, whose head and underparts gleam like buttercups in sunshine. Methodically, unhurriedly, the Blue-Winged Warbler ambles through thick foliage, picking off a caterpillar here and gleaning a spider there. At times it may dangle upside down like a chickadee or titmouse, but this matter-of-fact feeder seems to have none of the flash of other members of the warbler family.
Where ranges of blue-winged and golden-winged warblers overlap, interbreeding occurs, and the young inherit traits of both parents. The classic hybrid types have even been given their own names - the Brewster's Warbler and the less common Lawrence's Warbler. These hybrids are fertile and may interbreed with either parent species, or with still other hybrid birds.

With so  much mixing and matching, a basic question occurs: are blue-winged and golden-winged warblers really different species at all? The question may not be asked for long. Where ranges overlap, blue-wings generally increase and golden-wings decline, the victims of genetic swamping. Eventually, golden-winged warblers may simply disappear, their identity diluted to the vanishing point within the blue-wings genetic pool.