Green-bearded helmetcrest

The green-bearded helmetcrest was formally described in 1840 by the French ornithologist Auguste Boissonneau from a specimen collected near Bogotá in central Colombia.[3][4] This species is now placed in the genus Oxypogon that was introduced by the English ornithologist John Gould in 1848.[5][6] The genus name combines the Ancient Greek oxy meaning ″sharp or pointed″ and pogon meaning beard. The species name was chosen to honour the French naturalist and collector Félix Guérin-Méneville.[7] The species is monotypic: no subspecies are recognised.[6]

This bird was formerly considered a species named bearded helmetcrest with four subspecies. In 2014 the South America Classification Committee agreed to a proposal to split this species into four separate species based on plumage differences and morphometrics.[8] The other species are the buffy helmetcrest of the Cordillera Central, the blue-bearded helmetcrest of the Sierra Nevada de Santa Marta and the white-bearded helmetcrest of the Cordillera de Mérida in Venezuela.[6][9]

A medium-sized hummingbird. The male has a long crest and a black face outlined in white. Females and juvenile birds lack the crest, and show a broad white band across the chest. The chin and throat of both sexes are white with adult males showing a viridian green ″beard″ or stripe. The upperparts are bronzy-olive green. The bird has a short needle-shaped bill and grey feet.[2]

The bird is a resident breeding species of the high Eastern Andes, principally in the area from south of Bogotá through Boyacá Department and as far north as Bucaramanga.[1]

It feeds on low vegetation, including fields planted with garlic, onion and other crops. It is most often seen in the páramo, where it perches to feed on the flowers of Espeletia.[2] It is thought that the short, fine bill of this bird and the other Oxypogon species is an adaption to facilitate the extracting of nectar from the numerous tiny florets of the flower heads of these plants.[10]