Black-whiskered Vireos in the United States live mostly in the southern half of coastal Florida where mangroves and other tropical and subtropical tree species grow. Black-whiskered Vireos can also be numerous in “hammock” forests bordering mangroves. Typical tree species are black, white, and red mangroves, sea-grape, gumbo-limbo, poisonwood, and strangler fig. In some parts of Florida, Black-whiskered Vireos also breed in suburban neighborhoods with an abundance of native Caribbean trees. This species shows a remarkable ability to adapt to many other types of tropical habitats across its range, including dry and wet limestone forests, coastal forests (especially near mangroves), wet montane forests, mahogany plantations, and developed areas with trees and other vegetation. Black-whiskered Vireos are much less numerous in drier habitats as a rule, and appear to be rare in montane pine forests. Among the important trees for them in the Caribbean are West Indian treefern, matchwood, loblolly sweetwood, muskwood, roughbark lignum-vitae, ice-cream-bean tree, golden spoon, peanut butter fruit tree, white manjack, mameyuelo, granadillo bobo, camboatá, cupey de monte, roble de sierra, and several cecropia and fig species. Wintering birds in South America inhabit rainforests, seasonally flooded forests (called várzea), mangroves, and forest edges, including disturbed areas, up to 4,000 feet elevation. They are much less common in the interior of forests than around openings and edges, including where hurricanes have damaged forests and created new growth.Back to top
Black-whiskered Vireos eat both fruit and insects, and they consume a greater proportion of fruit than smaller vireo species with which they coexist across their Caribbean range. They forage by moving slowly through the middle and upper levels of trees and tall shrubs, either plucking fruit or gleaning insects as they go. Occasionally, they hover to catch insects, but mostly they snatch them from leaves, twigs, and fruit clusters. They also probe into small bromeliads, ferns, orchids, and other arboreal plants for prey such as insects, and possibly tiny frogs. Prey includes caterpillars, spiders, beetles, weevils, wasps, bees, assassin bugs, earwigs, and insect eggs. They also eat fruits of cecropia, fig, barberry, ragweed, muskwood, matchwood, royal palm, tree poppy (Bocconia frutescens), autograph tree, aguacatillo, camboatá, and gumbo-limbo.Back to top
Nests are set in a branch fork or on horizontal tree branch, 4–21 feet above the ground, often in mangrove, mahogany, or another substantial evergreen tree but sometimes in a smaller bush such as hibiscus.
The female constructs a deep cup of dried grass, lichens, and spiderwebs, lining it with fine grass, rootlets, and palm or palmetto fibers. Nests average about 2.9 inches across and 2.4 inches tall, with an interior cup 2 inches across and 1.7 inches deep.
|Clutch Size:||2-4 eggs|
|Egg Description:||White with a few small brown dots.|
|Condition at Hatching:||Helpless with eyes closed.|
Black-whiskered Vireo males sing to claim territories; they often clash with other males by loudly calling, singing, and sometimes fighting. Males in conflict raise the crown feathers, droop the wings, spread the tail feathers, and vocalize loudly as a threat display, rather than fight. Pairs sometimes confront other pairs with similar displays. During courtship, males chase females in flight. Males may also feed females, a behavior called courtship feeding. The female builds the nest alone, with the male following her closely and singing as she selects the site and constructs the nest. Both male and female share incubation and chick-rearing duties. Shiny Cowbirds often parasitize (lay eggs in) Black-whiskered Vireo nests. Like other large vireo species, Black-whiskered Vireos often sound the alarm when predators such as snakes, hawks, or cats appear, alerting other songbirds to their presence. Wintering Black-whiskered Vireos of the migratory subspecies often join mixed-species flocks. Back to top
Partners in Flight estimates a global breeding population of 6.2 million individuals and rates the Black-whiskered Vireo a 12 out of 20 on the Continental Concern Score, indicating a species of relatively low conservation concern. Where the species overlaps with Shiny Cowbirds, increasing numbers of the latter have reduced populations of the vireo. Sea-level rise and the destruction of mangrove forests and other tropical habitats pose significant conservation concerns for the Black-whiskered Vireo.Back to top
Chace, Jameson F., Bethany L. Woodworth and Alexander Cruz. (2002). Black-whiskered Vireo (Vireo altiloquus), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.