Chocó vireo
The Choco vireo is a species of bird in the family Vireonidae, the vireos, greenlets, and shrike-babblers. It is found in Colombia and Ecuador.
Discovery
The Choco vireo was first observed on August 25, 1991, by Paul Salaman in southwestern Colombia's Nariño Department. The site, located at an elevation of about, was in a narrow strip of intact, very wet forest along the Rio Nambi. In early June 1992 ornithologist Gary Stiles observed and collected the type specimen while working further north in Alto de Pisones in Risaralda Department. Salaman and Stiles took the novel approach of auctioning off the naming rights to the vireo's scientific name in order to raise money for conservation of the bird's habitat. Bernard Master, the first American birder to have seen a representative of every bird family in the world, won the auction with a bid of US $75,000 and named it Vireo masteri. This donation was used to create the Pangan ProAves Reserve in Colombia.Taxonomy and systematics
The Choco vireo is monotypic.Description
The Choco vireo is about long and weighs about. The sexes have the same plumage. Adults have an olive crown, a yellow buff to dingy yellowish supercilium, white arcs above and below the eye, a dusky stripe from the lores through the eye, and yellow-buff ear coverts. Their nape and upperparts are olive that becomes brighter by the rump. Their wing coverts are dusky gray with wide white tips that show as two wing bars. Their primaries and secondaries are dark brown with thin yellow-green or white edges. Their central pair of rectrices are olive and the rest dark brown; the outer three pairs have pale dingy white to pale brown edges. Their throat is yellow-tinged whitish, their breast buff yellow, their belly dingy white with olive sides, and their undertail coverts straw yellow. They have a dark brown iris, a blackish maxilla, a pale dusky mandible with a paler base, and bluish gray legs and feet. Juveniles have a paler supercilium, more yellow-tinged wing bars, and paler, more creamy, underparts than adults.Distribution and habitat
The Choco vireo is a bird of the Chocó region, which is famed for its high biological diversity. As of 2023 it was known from only four locations between Colombia's Alto de Pisiones in the north and near La Delicia, Pichincha Province, Ecuador in the south. Searches between those areas have not found the species.The Choco vireo primarily inhabits the interior and edges of primary rainforest on both level ground and on steep slopes. Its habitat is characterized by a canopy about high with gaps made by fallen trees; the trees are heavy with moss and epiphytes. One source states that its elevational span is and another says.