The northern parula (Setophaga americana) is a small New World warbler. It breeds in eastern North America from southern Canada to Florida.
This species is migratory, wintering in southern Florida, northern Central America, the West Indies and most of the Lesser Antilles. This species is a very rare vagrant to western Europe.
While the species is still common as a breeder across most of eastern North America, there are conspicuous gaps in their breeding range that were likely once breeding grounds. They have been extirpated as a breeder from much of the Midwest as well as from many areas in Massachusetts, New Jersey, Connecticut, New York, Rhode Island and Vermont. Explanations for the disappearance may be changes in habitat or increasing air pollution, which limited the growth of epiphytes on trees that the warbler depended on for nesting. A further explanation is the clear-cutting and bog draining that have significantly reduced the amount of suitable habitat in eastern North America. source