Song: Song is a variable trill, usually in two parts. Second part may be higher or lower in pitch, often tapering off in volume. Not as emphatic as Wilson's Warbler and usually without Wilson's abrupt ending. May occasionally sing a one-parted trill, causing confusion with Pine Warbler, Palm Warbler, Orange-crowned Warbler, Chipping Sparrrow, and Dark-eyed Junco.
Sound: Monty Brigham
(Bird Sounds of Canada); 1976 Sept 26; Canada, Québec; Aylmer - Cottage; Adult; Primary Sound;