Sp. Char. (No. 1,017 ♀) Above olive-green, strongly glossed with ashy; the head and nape above more distinctly ashy, but without decided line of demarcation behind, and without dusky edge; rump pure olive. Stripe from nostrils over eye to nape, eyelids, and space below eye, creamy-white. A rather dusky post-ocular and loral spot, the latter not extending to the bill. Under parts white, with tinge of greenish-yellow (occasionally of creamy fulvous or buff), especially on breast; sides more olivaceous. Crissum and axillars scarcely more yellowish. Quills and rectrices wood-brown, edged internally with whitish, externally with olivaceous, except perhaps on longer primaries. Edge of wing white. Larger wing-coverts grayish-brown, with paler edges, and no trace of olivaceous. Bill horn-color above, paler below.
First quill very short or spurious; second about equal to, generally rather longer than sixth; third longest; fourth, then fifth a little shorter.
Fresh specimen: Total length, 5.33; expanse of wings, 8.35; wing from carpal joint 2.85. Prepared specimen: Total length, 4.80; wing, 2.75; tail, 2.25. Sexes alike. Iris brown.
Hab. Eastern North America to Fort Simpson. Cordova and Oaxaca only southern localities recorded. Not West Indian.
A very young bird has a very cottony plumage, and differs in tints, having the top of the head and the nape a soft whitish isabella-color, this tingeing the back; the lower parts are wholly unsoiled white; the middle and secondary
coverts are obscurely tipped with light brown, forming two indistinct bands across the wing.
A specimen (No. 54,262) from Orizaba is, in positively every respect, exactly intermediate between this species and V. josephæ of Costa Rica, Ecuador, etc. (See footnote on page 360.) The crown is brown, decidedly darker than, and different in tint from, the back, but less so than in josephæ; the back is less olive than in the latter, and less gray than in the former. The lower parts are more yellow than in gilvus, and less so than in josephæ, the superciliary stripe whiter and extending farther back than in the former, and less pure white and shorter than in the latter, etc.
Habits. The Warbling Vireo has only a slightly less extended distribution than the Red-eyed, being found throughout all Eastern North America, as far north as Fort Simpson and Selkirk Settlement, and west to the Missouri River, and breeding as far south as Louisiana. It is stated by Audubon to be found on the Columbia River, but in this he probably referred to the Western race, V. swainsoni. That writer never observed this species in Louisiana or Kentucky, nor in the maritime part of Georgia, and its manner of entering the United States he was unable to ascertain. Where it moves to in the winter is also unknown, none having been met with in the West Indies, and only at a few points in Mexico, Cordova, Oaxaca, and the State of Vera Cruz. It was, however, found breeding at Calcasieu, Louisiana, by Mr. Würdemann.
It breeds abundantly from Virginia to Nova Scotia, and throughout the Northwestern States. West of the Rocky Mountains it is replaced by a closely allied species, the V. swainsoni. This Vireo, more than any other of its genus, if not exclusively, is to a large extent a resident of villages, towns, and even cities. It is by far the sweetest singer that ventures within their crowded streets and public squares,—although Mr. Cassin gives his preference to the notes of the Red-eyed,—and the melody of its song is exquisitely soft and beautiful. It is chiefly to be found among the tall trees, in the vicinity of dwellings, where it seems to delight to stay, and from their highest tops to suspend its pensile nest. It is especially abundant among the elms on Boston Common, where at almost any hour of the day, from early in the month of May until long after summer has gone, may be heard the prolonged notes of this, one of the sweetest and most constant of our singers. Its voice is not powerful, but its melody is flute-like and tender. Throughout the last of May, and in June and July, their charming song may be heard amid the din of the city from earliest dawn till nightfall, and rarely ceases even in the noontide heat, when all other birds are silent. It is ever in motion, while thus singing; and its sweetest notes are given forth as it moves among the tree-tops in search of insects. It is not only one of our most constant singers, but it remains musical almost until its departure for the South in October.
The Warbling Vireo appears in the Middle States about the 15th of April,