This species account is dedicated in honor of Victor Emanuel, member of the Cornell Lab of Ornithology's Administrative Board.
The Hooded Warbler is a small migratory songbird that breeds in southernmost Canada and the eastern United States and winters in Central America. On its breeding range, this species inhabits mixed hardwood forests in the north and cypress-gum swamps in the south. The species is considered a “gap specialist” as its habitat, whether in large forest tracts or small fragments, typically includes gap or edge habitat that is preferred by females for nesting.
The Hooded Warbler is declining only in parts of its range, perhaps owing to its ability to live in fragments and logged or slightly disturbed habitats. The creation of small gaps by selective logging can enhance its nesting habitat through the maintenance of a dense shrub cover, although pairs inhabiting small fragments have lower productivity usually due to high parasitism by Brown-headed Cowbirds. This warbler is considered threatened in Canada where forest habitat is becoming increasingly scarce and fragmented.
Overwintering individuals are strongly territorial and segregate by sex, with males most likely to be found in mature forest and females in scrub, secondary forest, and disturbed habitats—the first documented case of such habitat segregation. Many individuals appear unable to obtain winter territories owing to this intense intraspecific competition, and little is known about the ecological or conservation implications of such behavior.
Adult male Hooded Warblers have distinctive plumage, most notably a conspicuous black hood contrasting with yellow cheeks and forehead. Females vary greatly in the extent of their black hood, and early reports were mistaken in identifying dark females as subadult males; the adaptive significance of such variation in female plumage remains unknown. Adults retain their plumage coloration year-round, and there is no noted geographic variation in appearance.
Males defend nesting and feeding territories where they attract a single mate. Males have individually distinctive songs and are known to associate each neighbor's song with its usual location, a form of individual recognition. Long-term memory enables males to remember their individual neighbor's songs from year to year, presumably reducing the costs of territorial defense. Nevertheless, neighbors are a main threat to paternity. A key feature of this species' social behavior is extra-pair matings; about one-third of the females produce offspring fathered by a neighboring male.
Recent work has focused on edge habitat use and the effects of fragmentation on the species. Female choice of territory and social mate from year to year, as well as population regulation by carryover effects from winter habitat, remain largely unstudied in this species.