Hooded Warbler (Wilsonia citrina)

Distribution

Breeding: Primarily a species of the southeastern United States. The breeding range extends west to eastern Oklahoma and Texas, southern Missouri, Iowa and southern Wisconsin, and north to southern Michigan, southern Ontario, New York and Connecticut.

Winter: Primarily from eastern Mexico through Central America, mostly on the Atlantic slope (Belize, Guatemala, and Honduras); usually not as far south as Panama, but makes rare appearances in northern South America.

Breeding habitat

Reaches highest densities in large tracts of mature, uninterrupted, deciduous forest with a dense shrub layer and scant ground cover. Breeds in both upland (usually oak-hickory) and bottomland forest types; in Canada, restricted to Carolinian forests of southern Ontario. Somewhat tolerant of disturbance, such as selective logging, that promotes growth of shrubs.

Conservation status

This warbler is of moderate conservation importance, because of its relatively small total breeding range and associations with mature deciduous forests. Breeding populations appear to be stable or even increasing in some areas at present; populations may be more vulnerable on their wintering grounds, where they generally inhabit rapidly disappearing lowland tropical forests. Relationships with forest fragmentation and silvicultural practices are poorly known and will be important for sustaining future populations.

Description

Male: The black hood, which is created by the solid black crown and throat connected along the sides of the neck, sets off the brilliant yellow face and forehead. Upperparts are olive, underparts yellow. White patches in tail seen during behavioral displays where tail is spread.

Female: While some adult females may resemble the male’s hooded pattern, most show a yellow face and throat bordered below by black. While the front of the crown may be black, the rear crown is mostly olive, and blends into the back.

Juvenile: Extensively brownish-olive above, dull buff below with light yellow mottling on the breast.

Vocalizations

Songs: Males have several song types, but the most common is ta-wit ta-wit ta-wit tee-yo. Other song types are sung irregularly, but share the sweet, clear quality of notes and often the wit-tee-yo ending.

Calls: Both males and females give the loud and metallic-sounding peenk notes, primarily by the female during the breeding season, but during aggressive interactions rates become very frequent. Both give this note when defending winter territories.

Foraging strategy

Gleans from foliage while moving about a shrub or sapling, but will also hover-glean and sally for flying prey items.

Diet

Exclusively insects, including small spiders, caterpillars, moths, grasshoppers, beetles, and flies.

Behavior and displays

• Tail fanning occurs frequently in both sexes, revealing the large white tail spots of the dark outer tail feathers.

• During the breeding season, males chase intruding males from their territory in chases that may last hours.

• In response to territorial intrusions, males give visual threat displays:

Wing droop: when landing near an intruder, the wings are held slightly out, head is pulled in and feathers fluffed so that bird has hunched appearance.

Head switch: a variation of the wing droop in which the bird’s body is turned away from the intruder and head is turned side-to-side.

Upward: in high intensity situations the bird faces intruder, stands close to it, and moves up and down from this position to the wing droop.

Finally, “supplanting attacks,” “direct attacks,” and “bill snapping” are also included in territorial disputes.

• Precopulatory displays, copulation, and postcopulatory displays are not known.

Courtship

• No information.

Nesting

Nest Site: Nest sites are primarily along streams and ravine edges in dense deciduous undergrowth. Nests placed in shrubs, often within or along the edge of secondary forest. Frequently used substrates include blackberry, beech, black cherry, and prickly gooseberry, but also mapleleaf viburnum, white ash, black kohash, blue kohash, sugar maple, wild rose, yellow birch, hawthron, and hemlock. In rare cases, the nest is built in the dead branches of a fallen limb, or pile of debris.

Height: Ranges from 1–5 feet (0.3–1.5 meters) above the ground.

Nest: An open cup woven of soft inner bark, fine grasses, animal hair, and plant down. Outer portion of nest consists of dead leaves and leaf skeletons, giving nest a camouflaged appearance. The nest is supported with at least 2 vertical or oblique stems of the sapling or shrub; nest materials are held together with spider webs. Built solely by female, although male is sometimes nearby.

Eggs: 3–4 creamy white eggs, scattered with markings concentrated at large end.

Incubation period: 12 days, exclusively by female. Male does not often approach nest and incubation feeding has rarely been observed.

Nestling period: Young are altricial at hatching, naked except for sparse down, eyes closed, with little coordinated movement and no ability to find food. Both males and females feed young from hatch day. The young remain largely inactive until parent arrives with food, then stretch neck upward and gape widely. Brooding of nestlings is performed entirely by the female.

Fledgling period: Parents often split the brood, females dispersing with their portion while males generally stay on home territory. The young are independent 4–5 weeks after leaving the nest.

Broods: Usually single brooded.

Cowbird Parasitism: Frequent Brown-headed Cowbird host throughout range.

Notes

• Predation rates are high throughout range, but if the nest is depredated the female will often renest elsewhere.

• Returning males usually occupy same territory in subsequent years.