Black-whiskered Vireo

The Black-whiskered Vireo, Vireo altiloquus, presents itself as a modestly sized passerine, measuring 14–15 cm in length, with a wingspan extending to 25 cm, and tipping the scales at a delicate 17–19 grams. Its legs are a robust blue-grey, complementing a stout bill, while the adult bird is adorned with dull olive-green upperparts and a pristine white underbelly. A touch of yellow graces the flanks and beneath the tail, and the eyes are a striking red set against a grey-brown crown with subtle dusky margins. A dark line pierces through the eyes, contrasted by a white eyebrow stripe, and a distinctive black line, the eponymous "whisker", marks the neck sides. The juvenile mirrors the adult but gazes through brown-red eyes.

Identification Tips

Distinguishable from its cousin, the Red-eyed Vireo, the Black-whiskered Vireo is somewhat duller and browner above. The key to its identification lies in the characteristic black whisker mark. The Florida race, V. a. barbatulus, is notable for its bill, which is shorter by 15% compared to the northern Caribbean subspecies V. a. bonairensis.

Habitat

The Black-whiskered Vireo favors open deciduous woodlands and cultivated areas for breeding. In Florida, it also thrives among the mangroves.

Distribution

This bird breeds in the southern reaches of Florida, USA, and across the West Indies, venturing as far south as the offshore islands of Venezuela. It is a partial migrant, with northern populations wintering from the Greater Antilles to northern South America. Occasionally, it appears as a rare vagrant in Costa Rica.

Behaviour

The Black-whiskered Vireo is an active forager, gleaning insects from tree foliage with a penchant for hovering during its search. It constructs a cup nest in a tree branch fork, where it lays 2-3 white eggs. In the United States, it is affected by nest parasitism from the Brown-headed Cowbird, and further south, the Shiny Cowbird.

Song & Calls

The bird's vocal expression is a distinctive three-syllable whip, "Tom Kelly", more abrupt than the song of the Red-eyed Vireo.

Diet and Feeding

In addition to its insectivorous pursuits, the Black-whiskered Vireo occasionally supplements its diet with small quantities of berries.

Conservation status

The Black-whiskered Vireo is currently classified as Least Concern on the IUCN Red List, indicating a stable population without immediate threats to its survival.