Length5.30 inches. About an inch shorter than the English sparrow.
MaleSlate-color, not blue above ; lightest on forehead and darkest on lower back. Wings and tail edged with bluish. Cheeks, chin, throat, upper breast, and sides black. Breast and underneath white. White spots on wings, and a little white on tail.
FemaleOlive-green above ; underneath soiled yellow. Wing-spots inconspicuous. Tail generally has a faint bluish tinge. RangeEastern North America, from Labrador to tropics, where it winters.
MigrationsMay. September. Usually a migrant only in the United States.
Whoever looks for this beautifully marked warbler among the bluebirds, will wish that the man who named him had possessed a truer eye for color. But if the name so illy fits the bright slate-colored male, how grieved must be his little oliveand-yellow mate to answer to the name of black-throated blue warbler when she has neither a black throat nor a blue feather! It is not easy to distinguish her as she flits about the twigs and leaves of the garden in May or early autumn, except as she is seen in company with her husband, whose name she has taken with him for better or for worse. The white spot on the wings should always be looked for to positively identify this bird.
Before flying up to a twig to peck off the insects, the birds have a pretty vireo trick of cocking their heads on one side to investigate the quantity hidden underneath the leaves. They seem less nervous and more deliberate than many of their restless family.
Most warblers go over the Canada border to nest, but there are many records of the nests of this species in the Alleghanies as far south as Georgia, in the Catskills, in Connecticut, northern Minnesota and Michigan. Laurel thickets and moist undergrowth of woods in the United States, and more commonly pine woods in Canada, are the favorite nesting haunts. A sharp Zip, Zip, like some midsummer insect’s noise, is the bird’s call-note, but its love-song, Zee, Zee, Zee, or twee, twea, twea-e-e, as one authority writes it, is only rarely heard in the migrations. It is a languid, drawling little strain, with an upward slide that is easily drowned in the full bird chorus of May.