Hooded Warbler Setophaga citrina Scientific name definitions

The Hooded Warbler is a small migratory songbird that breeds in deciduous and mixed forest habitats in the eastern United States and southernmost Canada, and overwinters in southern Mexico, northern Central America, and the Caribbean. On the breeding grounds, the species is considered a “gap specialist,” because it relies on a dense understory shrub layer found along forest edges or in light gaps created by natural treefalls or selective timber harvest. Unlike many migratory songbirds that are undergoing steep population declines, the global population of the Hooded Warbler has doubled since the 1970s, and its breeding range is expanding northward, a distributional change likely fueled at least in part by climate change.

The male has a distinctive black hood that it acquires when it is about 30 days old and retains the rest of its life. The female, however, shows considerable age-related and individual variation in the extent of the black hood. The first-year female has few or no black feathers on its head and neck, but older females vary tremendously, from birds lacking black and resembling the young female to birds with a complete black hood that is almost identical to that worn by the male; the adaptive significance of such wide individual variation in female plumage remains unknown.

Perhaps the most conspicuous feature of Hooded Warbler behavior is its habit of continuously flicking open its tail while foraging, briefly revealing the large white spots on the outer tail feathers. This behavior—which occurs throughout the year and is shown by the male, female, and even developing fledglings—enhances overall foraging performance by startling potential prey, particularly the winged insects that are a major component of the bird’s diet.

On the breeding grounds, the male defends nesting and feeding territories where it attracts one or sometimes 2–3 mates. 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 the male to remember its individual neighbor's songs from year to year, presumably reducing the costs of territorial defense. Nevertheless, neighbors are a main threat to paternity, as 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.

The Hooded Warbler has a prolonged nesting season that can extend to mid-August, and pairs regularly raise two broods. However, the extended breeding season creates complex trade-offs among the conflicting demands of late-season parental care, the intense late-summer molt, and the eventual southward migration to the Neotropical overwintering range. One frequently observed trade-off is molt-associated desertion of offspring; in late summer, many males engaged in high-intensity flight feather molt desert their late-season nestlings and fledglings, leaving the female responsible for all remaining parental care. Females appear to fully compensate for the loss of male care, but how late-season offspring care, molt, and frequent male desertion interact with other important life-cycle events—such as fall migration, overwinter survival, and return to the breeding grounds the following spring—are questions remaining to be answered.

On the nonbreeding range, 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 by sex. Many individuals appear unable to obtain overwintering territories owing to this intense intraspecific competition, and we are only beginning to understand the ecological and conservation implications of sexual habitat segregation on the overwintering range.