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.[5][6] This species is now placed in the genus Oxypogon that was introduced by the English ornithologist John Gould in 1848.[7][8] 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.[9] The species is monotypic: no subspecies are recognised.[3]

The green-bearded helmetcrest was formerly considered a species named bearded helmetcrest with four subspecies. In 2014 the South America Classification Committee (SACC) of the American Ornithological Society agreed to a proposal to split this species into four separate species based on plumage differences and morphometrics. Other taxonomies soon followed suit.[10][11][3][12][4] The other species are the buffy helmetcrest (O. stuebelii) of the Cordillera Central, the blue-bearded helmetcrest (O. cyanolaemus) of the Sierra Nevada de Santa Marta, and the white-bearded helmetcrest (O. lindenii) of the Cordillera de Mérida in Venezuela.[3]

The green-bearded helmetcrest is 11.2 to 12.7 cm (4.4 to 5.0 in) long. Males weight about 5.7 g (0.20 oz) and females 4.8 g (0.17 oz) It has a short straight black bill. The adult male has a long white crest and a mostly dark brown to black face with a white "collar". Its upperparts are bronzy. It has a thin glittering green gorget with white edges that forms a "beard". The rest of the underparts are grayish bronzy. The tail is moderately long, forked, and coppery to bronzy green with much white on the outer feathers. The adult female is similar to the male but lacks the crest and beard, and its underparts are buffy white with some greenish mottling. Juveniles resemble the adult female; the male has a partial crest and beard.[13]

The green-bearded helmetcrest is found in Colombia's Eastern Andes as far south as Cundinamarca Department. It inhabits humid páramo, especially that with Espeletia vegetation. It also sometimes occurs at the edge of Polylepis woodlands. Females often occur in gorges while males tend to remain in more open landscapes. In elevation the species ranges between 3,000 and 4,200 m (9,800 and 13,800 ft).[13]

The IUCN has assessed the green-bearded helmetcrest as being of Least Concern. It has a limited range and its population size is not known and believed to be decreasing.[1] It is considered locally common and occurs in several protected areas.[13]