Choco Vireo Vireo masteri Scientific name definitions

Prior to the 1990s, the relatively nondescript Choco Vireo was unknown to science, and perhaps to any human, because it resides in the upper canopy of the cloud forest at but a few locations in Colombia and Ecuador. It was first formally described in 1996 based on a specimen collected at Alto de Pisones, Departamento del Risaralda, Colombia, and subsequently it has been found at one other location in Colombia and two in northern Ecuador. All sites lie within the Choco Ecoregion, and all consist of primary rainforest at an elevation of 1,200–2,100 m, with a broken canopy that is approximately 20–30 m in height. The Choco Vireo inhabits that canopy, where it peeks beneath leaves for insects (and likely other arthropods) upon which to feast.

Generally, the Choco Vireo is found singly or in pairs, sometimes with a juvenile in tow. That said, it will joined mixed-species feeding flocks that enter its territory, but does not follow them when they leave. Like many vireos, it is an incessant singer, not uncommonly singing for 20 or 30 minutes at a time. Each song, which lasts only two seconds or so, typically consists of three parts. Compared to the songs of other vireos, that of the Choco Vireo is rather brief and somewhat high-pitched. Though drab overall, its appearance is rather distinct among vireos, combining a long bold supercilium with a pair of bright wing bars.

As of 2007, the global population of the Choco Vireo was estimated at 15,600 individuals, but the current population is probably somewhat lower, because numbers are thought to have declined approximately 20% between 2000 and 2018 due to habitat loss. Though this species is currently listed as Near Threatened by the IUCN, one could be argue that it should be considered Endangered, as it was until 2022. Conservation of this species and, perhaps more importantly, its habitat is urgent. For this to happen, deforestation needs to slow dramatically and forestry habits need to be more in tune with preserving the overall environment. More locations need governmental protection, and those that are theoretically protected would benefit from greater attention.