It leaves Louisiana in the beginning of October. I have never seen the species farther eastward than the State of Jersey, where I killed several within a few miles of Philadelphia, not however until my last visit to that State in 1829. It is frequent in the barrens of Kentucky, and up the Mississippi, as far at least as St Genevieve, where I shot two individuals many years ago.
Its flight is short, undetermined, and is performed in zig-zag lines, as in most of its tribe. It sometimes ascends twenty or thirty yards in the air, as if with an intention of going to a great distance, but still moving in a zig-zag manner, when it suddenly turns about, and comes down near the place from which it set out. It does not chase insects on wing, but feeds in a great measure on the smaller kinds of spiders, not neglecting, however, to seize other insects when they come within reach. It remains almost constantly among the bushes, and is seldom seen on trees of any size.
Sylvia solitaria, Ch. Bonaparte, Synops. of Birds of the United States, p. 87.
Blue-winged Yellow Warbler, Wils. Amer. Ornith. vol. ii. p. 109. Pl. 15. fig. 4.
Adult Male. Plate XX. Fig. 1.
Bill nearly as long as the head, straightish, subulato-conical, acute, as deep as broad at the base, the edges acute, the gap line a little deflected at the base. Nostrils basal, lateral, elliptical, half-closed by a membrane. Head rather small. Neck short. Body slender. Feet of ordinary length, slender; tarsus longer than the middle toe, covered anteriorly by a few scutella, the uppermost long; toes scutellate above, the inner free, the hind toe of moderate size; claws slender, compressed, acute, arched.
Plumage soft, blended, tufty. Wings of ordinary length, acute, the second quill longest. Tail longish, rounded when expanded, slightly forked when closed.
Bill black, with a pale margin. Iris dark brown. Feet and claws flesh-colour, tinged with yellow. Forehead, crown, and under parts of a rich bright-yellow. Back of the head and neck, the back and upper tail coverts bright grass-green. Lore black. Wings greyish-blue, slightly margined with paler, the first two rows of coverts tipped with whitish. Four middle tail-feathers greyish-blue, the outer webs of the rest, and an oblique portion of the outer feather at the end, of the same colour, their inner webs white.
Length 4¾ inches, extent of wings 7; bill along the ridge ½, along the gap 1.
Adult Female. Plate XX. Fig. 2.