Song: Rapidly repeated (1 per second) "eree" call with mechanical trilling quality. Complex song consisting of a series of somewhat buzzy "zree" notes and followed by "ee-haw" notes reminiscent of the braying of a donkey. Both rapidly repeated call and song given in flight as bird ascends, the song often preceded by a series of "eree" calls ("eree-eree-eree, zree-zree-zree-zree, ee-haw, ee-haw").
Sound: Ted Miller (Bird Sounds of Canada); 1979 Jun 4; Canada, Manitoba; Churchill; Adult; Primary Sound;