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.
The summer male Bay-breasted warblers are unmistakable. They have grey backs, black faces, and chestnut crowns, flanks, and throats. They also boast of bright yellow neck patches, and their underparts are white. They have two white wing bars, as well.
Breeding females essentially resemble washed-out versions of the male. The females are grayish above and white below, with much weaker head patterns. The females also only have chestnut markings on small flank patches, although tiny tints in their grey crowns have been observed. [Wikipedia]
Bay-breasted Warbler Facts [All About Birds]
- The Bay-breasted Warbler is closely related to the Blackpoll Warbler, and hybrids between the two species are known. The Bay-breasted Warbler is known to hybridize also with Yellow-rumped and Blackburnian Warblers.
- Adult Bay-breasted Warblers appear to follow a more western migratory route south in the fall than first-year birds. More adults migrate west of the Appalachian Mountains than east of them, while first-year birds are frequent along the coast.
- In contrast to the more stable populations of other warblers, Bay-breasted Warbler numbers go up and down depending on outbreaks of the spruce budworm. It is abundant during infestations, but declines or even disappears from some areas a few years later.
- The oldest known Bay-breasted Warbler was at least 4 years, 11 months old.