The Black-whiskered Vireo (Vireo altiloquus), is a small passerine bird found in southern Florida, USA, and the West Indies as far south as the offshore islands of Venezuela. This bird is a partial migrant. Northern birds winter from the Greater Antilles to northern South America. It is a rare vagrant to Costa Rica. Its habitat is open deciduous wooded areas and cultivation, and in Florida also mangroves.
The Black-whiskered Vireo is 5.5 to 6.0 inches in length and has a 9.8 inch wingspan. This bird weighs about 0.63 ounces. It has thick blue-gray legs and a stout bill. The adult Black-whiskered Vireo has dull olive-green upper parts and white underparts, with yellowish on the flanks and under the tail. It has red eyes and a gray-brown crown with faint dusky edges. There is a dark line through the eyes and a white eyebrow stripe. There is a distinctive black line (the “whisker”) on the neck sides. Juvenile birds are similar, but have brown-red eyes.
The Black-whiskered Vireo gleans insects from tree foliage, sometimes hovering while foraging. It will also eat small quantities of berries.
This bird suffers from nest parasitism by the Brown-headed Cowbird in its US range, and Shiny Cowbird further south.