The adult male in autumn is scarcely different from the spring bird, there being merely a faint olive-tinge to the ash on top of the head, and the black jugular patch more restricted, being more concealed by the ashy borders to the feathers; the yellow beneath somewhat deeper.
Habits. The Mourning Warbler was first discovered and described by Wilson, who captured it in the early part of June, on the borders of a marsh, within a few miles of Philadelphia. This was the only specimen he ever met with. He found it flitting from one low bush to another in search of insects. It had a sprightly and pleasant warbling song, the novelty of which first attracted his attention. For a long while Wilson’s single bird remained unique, and from its excessive rarity Bonaparte conjectured that it might be an accidental variety of the Yellow-Throat. At present, though still of unfrequent occurrence, it is by no means a doubtful, though generally a comparatively rare species. Audubon mentions having received several specimens of this Warbler, procured in the neighborhood of Philadelphia, New York, and Vermont, all of which were obtained in the spring or summer months. He met with a single specimen in Louisiana, and thinks its habits closely resemble those of the Maryland Yellow-Throat.
Nuttall met with what he presumes to have been one of these birds in the Botanical Garden at Cambridge. It had all the manners of the Yellow-Throat, was busy in the search of insects in the low bushes, and, at intervals, warbled out some very pleasant notes, which partly resembled the lively chant of the Trichas, and in some degree the song of the Summer Yellow-Bird.
Professor Reinhardt states that two individuals of this species have been taken in Greenland,—one in Fiskenæsset, in 1846, and the other at Julianhaab, in 1853.
Mr. Turnbull gives it as still quite rare in Eastern Pennsylvania, arriving there in the middle of May on its way farther north. Mr. Lawrence includes it in his list of the birds of New York. Mr. Dresser obtained five specimens early in May, in Southern Texas.
It has been met with as far to the north as Greenland by Reinhardt, and in Selkirk Settlement by Donald Gunn. It has been procured in Eastern Mexico, in Panama, in Carlisle, Penn., Southern Illinois, Missouri, Nova Scotia, and various other places. It has been known to breed in Waterville, Me., and is not uncommon in Northwestern and Northern New York. A single specimen of this bird was obtained at Ocana, in Colombia, South America, by Mr. C. W. Wyatt.
Late in May, 1838, I have a note of having met with this species in Mount Auburn. The bird was fearless and unsuspecting, busily engaged, among some low shrubbery, in search of insects. It suffered our near presence, was often within a few feet, and was so readily distinguishable that my companion, with no acquaintance with birds, at once recognized it from Audubon’s plates. Its habits were the exact counterpart of those of the Yellow-Throat. We did not notice its song.
Mr. Maynard states that, May 21, 1866, Mr. William Brewster shot a male of this species in Cambridge, on the top of a tall tree. Another specimen was taken at Franconia Mountains, New Hampshire, August 3, 1867. It was in company with four fully fledged young, which it was feeding. The young were shy, and could not be procured. The old bird was catching flies, after the manner of Flycatchers. Mr. Maynard has met this species but once in Massachusetts, and then in May, among low bushes and in a swampy place. He has since found it rather common at Lake Umbagog, Maine, in June, where it breeds. He states that it frequents the bushes along fences, stone walls, and the edges of woods. The male often perches and sings in the early morning on the top rail of a fence, or the dead branch of a tree. Its song he speaks of as loud and clear, somewhat resembling that of the Seiurus noveboracensis.
Mr. Paine considers this Warbler to be very rare in Vermont. He once observed a pair, with their young, at Randolph. The male was singing a quite pleasing, though somewhat monotonous song.
Mr. George Welch met with these birds in the Adirondack region, New York, in June, 1870. They seemed rather abundant, and were evidently breeding there. He obtained a single specimen.