Life Histories of North American Wood Warblers, Part One and Part Two. Arthur Cleveland Bent
otherwise like the adult.”
The nuptial plumage is apparently assumed by wear and fading, the reddish-brown and yellowish colors becoming much duller. There are no specimens available of either young or adult birds that indicate a prenuptial molt.
The postnuptial molt seems to occur mainly in August, but perhaps earlier, and is evidently complete; I have seen birds in full, fresh autumn plumage as early as August 28. This fresh plumage is similar to the spring plumage, but the crown and back are nearly uniform brown, the crown is darker than in spring, the back is browner than in spring, and the breast and flanks are more or less clouded with grayish.
Food.—Howell (1924) says that “four stomachs of this bird from Alabama contained remains of caterpillars, spiders, and Hymenoptera (ants, bees, etc.).”
Brewster (1885a) considered the principal food to be small coleopterous insects, "as well as some small green worms that are found on water plants, such as the pond lily (Nymphaea odorata) and the Nelumbium (Cyamus flavicomus).
Behavior.—Swainson’s warbler is an unsuspicious bird and can be easily observed in its haunts where the vegetation is not too dense and tangled and the tree canopy overhead partially open. The neutral color of the bird is often apt to conceal him in the shadowy undergrowth. Singing males usually remain on the same perch during their periods of song, apparently disinclined to move. He often sings from the ground during insect hunting; Meanley (MS.) says: “It was so wrapped up in its song as to be absolutely unconcerned; it sang at my very feet with its head thrown back, its beak pointing perpendicularly toward the sky, pouring forth its resounding melody in the best of warbler fashion.”
The female is a close sitter, and the observer has usually to touch her before she leaves the nest. Grimes (1936) writes: “This bird would not leave her eggs until pushed off, and when I held my hand over the nest she straddled my fingers in trying to get back onto it. * * * When I did drive her away from the nest she fluttered along on the ground in the manner of a crippled bird, her actions manifestly intended to induce me to follow. This bird certainly was not badly frightened, for within a few minutes she was back on her nest, accepting deerflies from my fingers and swallowing them with apparent relish.”
Brewster (1885a) gives an admirable portrayal:
His gait is distinctly a walk, his motions gliding and graceful. Upon alighting in the branches, after being flushed from the ground, he assumes a statuesque attitude, like that of a startled Thrush. While singing he takes an easier posture, but rarely moves on his perch. If desirous of changing his position he flies from branch to branch instead of hopping through the twigs in the manner of most Warblers. Under the influence of excitement or jealousy he sometimes jets his tail, droops his wings, and raises the feathers of the crown in a loose crest, but the tail is never jerked like that of a Geothlypis, or wagged like that of a Siurus. On the contrary, his movements are all deliberate and composed, his disposition sedentary and phlegmatic.
Voice.—The bird student who hears the song of Swainson’s warbler as he sings in his wooded retreat is fortunate, for it is one of the outstanding warbler songs and, once heard, leaves a lasting impression upon the listener. At a distance it bears much resemblance to the songs of the hooded warbler and the Louisiana water-thrush. Close up, however, the appealing quality, lacking in the other two, impresses the listener strongly. The song has, in the majority of individuals, a highly ventriloquial effect, but the writer has listened to birds whose notes did not in the slightest degree possess this quality.
The song varies in length and number of notes but can be separated into two distinct parts; the first few notes are uttered rather slowly, the last ones more rapidly and on a descending scale. The second part closely follows the first, with no apparent separation. Brooks and Legg (1942) write: “It might be translated as whee, whee, whee, whip-poor-will, the first two (or three) introductory notes on an even pitch, the last whee a half-tone lower, and the slurred phrase with will separated into two syllables, and accented on the whip and on the wi-part of the will. The last phrase sounded at times remarkably like one of the songs of the White-eyed Vireo.”
When the singer begins his performance, the bill is pointed directly up, and he seems entirely unconscious of anything but his own musical efforts. “During his intervals of silence,” says N. C. Brown (1878), “he remains motionless, with plumage ruffled, as if completely lost in musical reverie.” Brewster (1885a) adds:
It is very loud, very rich, very beautiful, while it has an indescribably tender quality that thrills the senses after the sound has ceased. * * * Although a rarely fervent and ecstatic songster, our little friend is also a fitful and uncertain one. You may wait for hours near his retreat, even in early morning, or late afternoon, without hearing a note. But when the inspiration comes he floods the woods with music, one song often following another so quickly that there is scarce a pause for breath between. In this manner I have known him to sing for fully twenty minutes, although ordinarily the entire performance occupies less than half that time. Such outbursts may occur at almost any hour, even at noontide, and I have heard them in the gloomiest weather, when the woods were shrouded in mist and rain.
Several times the writer has seen males when the inspiration had not quite come to them; the bird would throw back its head but utter only one or two opening notes of his song.
The call note is a chip, which Brewster calls “a soft tchip indistinguishable from that of Parula americana.” But Murray (1935) writes that it is “more throaty and full-bodied than that of most Warblers.” Brooks and Legg (1942) describe it as “clear, penetrating chirps, having (to our ears) much the same quality as do the chirps of the Mourning Warbler. They are not quite so loud, but have a more ringing quality than those of the Hooded Warbler.”
Field marks.—[Author’s Note: Swainson’s warbler is a plainly colored bird, with no conspicuous field marks. It is brownish olive above and whitish below, with no white in either wings or tail; there is a whitish line over the eye and a dusky streak through it; but the bill is long and sharply pointed.]
DISTRIBUTION
Range.—Southeastern United States to southern Mexico.
Breeding range.—Until about 1935 Swainson’s warbler was considered to be confined in summer to the southern canebrakes and coastal marshes. It is now known to breed north to extreme southern Illinois, probably (seen in breeding season to Olive Branch, Duquoin, and Mount Carmel); southeastern Kentucky (Big Black Mountain); central to northern West Virginia (Charleston, Mount Lookout, Sutton, and Buzzard Rocks, Monongalia County); and southeastern Maryland (Pocomoke River Swamp). East to eastern Maryland (Pocomoke River Swamp); eastern Virginia (Warwick County and Dismal Swamp); eastern North Carolina (New Bern, Lake Ellis, and Red Springs); eastern South Carolina (Summerton, Charleston, and Yemassee); eastern Georgia (Savannah and Okefinokee Swamp); and northeastern Florida (Jacksonville). South to northern Florida (Jacksonville, Oldtown, Whitfield, and Pensacola) and southern Louisiana (Mandeville, New Orleans, and Baton Rouge). West to eastern Louisiana (Baton Rouge, Bayou Sara, and Jena); central Arkansas (Camden and Conway); extreme northeastern Oklahoma (Copan); and central Missouri (Concordia).
Within this large breeding area are two almost discontinuous breeding ranges: the coastal and swamp range long considered the only home of the species; and the more recently discovered mountain home along the slopes of the Allegheny Mountains from northern West Virginia nearly to the Georgia line where it has been found to an altitude of nearly 3,000 feet.
Winter range.—The winter home of the Swainson’s warbler is very imperfectly known from a dozen or more specimens, most of which are from Jamaica where it has been listed as a rare winter resident. There are records also from the Swan Islands (March 1); Santa Lucia, Quintana Roo; Pacaytain, Campeche; and the city of Veracruz. Two specimens have been taken near Habana, Cuba; one on September 25, the other in April; and one near Guantánamo on January 18, 1914.
Migration.—Dates of spring departure are: Jamaica, April 8. Cuba—Habana, April 14.
Early