Range. - Eastern North America, breeding from northern United States northward; winters in the Gulf States and southward.

These black-throated bluish-backed Warblers are abundant in swampy woodland both during migrations and at their breeding grounds; either sex can readily be identified in any plumage, by the presence of a small white spot at the base of the primaries. They nest in underbrush or low bushes only a few inches above the ground, making the nests of bark strips, moss rootlets, etc., lined with fine grasses or hair; the eggs are pale buffy white more or less dotted with pale brownish; size .65 x .50. Data. -Warren, Pa., June 9, 1891. 3 eggs. Nest one foot from the ground in brush; made of fine pieces of rotten wood, laurel bark and lined with fine grasses.

Greenish white.

Buffy white.

Mangrove Warblers. Black-throated Blue Warblers.

654a. Cairns Warbler. Dendroica Caerulescens Cairnsi

Range. - Mountain ranges of North Carolina to Georgia.

A darker form whose habits and eggs are identical with those of the last.