The bay-breasted warbler (Setophaga castanea) is a New World warbler. They breed in northern North America, specifically in Canada, into the Great Lakes region, and into northern New England. These birds are migratory, wintering in northwest South America and southern Central America. They are very rare vagrants to western Europe. This species is closely related to blackpoll warbler, but this species has a more southerly breeding range and a more northerly wintering area. Their songs are a repetitive high-pitched si si si.