Breeding males are distinctive with dark reddish-brown cap and sides, along with buffy nape. Two bold white wingbars. Females and fall birds are duller; most show at least some chestnut coloring on sides. Dullest birds are similar to Blackpoll and Pine Warblers; look for streaks on back, well-defined wingbars, and cleaner greenish-yellow head and neck. Prefers conifers during migration, but can be found in any woodland. Breeds in the boreal forest. In most of U.S. , only seen during migration. Winters in Central and South America. Listen carefully for extremely high-pitched, squeaky-wheel song, similar to a fast Black-and-white Warbler.