Small warbler with sharp bill that is very slightly downcurved. Plumages variable. Bright adult males are yellow below with black streaks, orange cheek patch, and white patch on wing. Dullest immature females are entirely gray with indistinct streaking below, usually with a hint of paler neck sides and greenish edges to wing feathers. Breeds in boreal forest of far northern U.S. and Canada. Winters in the Caribbean and Central America. Even in migration, shows a heavy preference for spruce trees.