Length: About 5¼ inches.

Male: Upper parts a dull grayish-blue, darker on the back, black bordering crown above the eye; cheeks, throat, and upper breast black; belly white; sides black and white; wings black, edged with blue, and with white next to body; a white patch on wing; tail bluish-black, outer feathers largely white.

Female: Very different from male; olive-green above, yellowish-white underneath; light streak over eyes; white patch near the base of the primary quills; tail bluish, with much less white than on males.

Song: “His song, though very versatile, is among the thinnest and most non-melodious of the family.”[152]

Habitat: “Black-throated blue warblers prefer clearings amidst hemlock woods or along hemlock-clad gully banks where there are dense underbrush, bushes, and stump sprouts bearing multitudes of large leaves.”[152]

Range: Eastern North America from Hudson Bay and Newfoundland south to the Northern States, and in the highlands and mountains to Massachusetts, Connecticut, Pennsylvania, and Maryland.

The Black-throated Blue Warbler, though not so brilliantly colored as many members of the family, is one of the neatest and best-groomed of all the warblers. As he flies from bough to bough or bush to bush he displays to fine advantage the clear black and white coloration, the white spots on the wings and tail flashing like the wings of a butterfly. He carries his wings and tail partially spread somewhat in the manner of the Redstart.... The male is not so nervously active as many other warblers....

“This warbler’s nest often contains an egg of the Cowbird. The nests are variously attached to slender scrubby bushes, 8 to 30 inches up, usually very close to old trails or old wood roads.... A constant characteristic of this warbler’s nest is the decoration of decayed, spongy pieces of light colored wood fastened to the outside.”[152]