Black-throated Blue Warbler
A medium-sized (5-5 ½ inches) wood warbler, the male Black-throated Blue Warbler is most easily identified by its bluish-gray head and back, black throat, and white breast. Female Black-throated Blue Warblers are pale brownish-gray overall with a faint white eye-stripes. The male Black-throated Blue Warbler may be distinguished from the related Cerulean Warbler (Setophaga ceruleaa) by that species’ lighter blue coloration and pale throat, whereas the female Black-throated Blue Warbler may be distinguished from the female Cerulean Warbler by that species’ greener body and paler breast. The Black-throated Blue Warbler breeds a limited area of southern Canada and portions of the eastern United States, mainly in the interior northeast and upper Midwest. Smaller numbers breed at higher elevations in the Appalachian Mountains as far south as northern Georgia. In winter, Black-throated Blue Warblers may be found in southern Florida, the West Indies, southern Mexico, and on the Caribbean the coast of northern Central America. Black-throated Blue Warblers primarily breed in deciduous or mixed deciduous and evergreen forests, preferring dense forest to more open woodland. In winter and on migration, this species is primarily found in humid tropical forests. Black-throated Blue Warblers primarily eat small invertebrates, including insects and spiders, but this species may also eat seeds and berries in winter. In appropriate habitat, Black-throated Blue Warblers may be observed foraging for insects on leaves, twigs, and branches in the lower canopy. Birdwatchers may also listen for this species’ song, a buzzing “zur zur zur zreee.” Black-throated Blue Warblers are primarily active during the day.
Common migrant chiefly in the higher deciduous woods in May, September, and early October. The male is grayish blue above; the female, olive green and lacks the black throat.
A female is on the left, a male on the right.