_Dendroica cærulescens cærulescens. Case 6, Figs. 58, 59_
The male is unmistakable; the female may be known
by the white spot at the base of the outer
wing-feathers. L. 5-1/4.
_Range._ Nests from northern Connecticut, the
mountains of Pennsylvania, and southern Michigan
north to Canada; winters in the tropics.
Washington, very common T.V., Apl. 19-May 30; Aug.
4-Oct. 9. Ossining, common T.V., Apl. 25-May 28;
Aug. 26-Oct. 10. Cambridge, rather common. T.V.,
May 10-25; Sept. 20-Oct. 10. N. Ohio, common.
T.V., Apl. 27-May 29; Sept. 5-Oct. 16. Glen
Ellyn, common T.V., Apl. 29-May 29; Aug. 25-Oct.
10. SE. Minn., uncommon T.V., May 11.
A true Wood Warbler, traveling through the trees with the scattered
bands of other members of his family as he journeys to and from his
summer home. This, in the northern part of his nesting range, is in
coniferous forests, in the southern part, deciduous forests. In both,
however, the birds require heavy undergrowth in which their bark-covered
nest is built within a foot or two of the ground. The grayish white,
brown-marked eggs are laid in late May or early June. Miss Paddock in
"Warblers of North America" describes the Black-throated Blue's song as
"an insect-like buzzing note repeated three or four times with a rising
inflection."
Cairn's Warbler (_D. c. cairnsi_) is a nearly related race having, in
the male, black centers to the feathers of the back. It nests in the
upper parts of the Alleghanies, from Maryland to Georgia, and winters in
the West Indies.