_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.