The blue-bearded helmetcrest (''Oxypogon cyanolaemus'') is a Critically Endangered species of

hummingbird Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 361 species and 113 genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are found in the tropics aro ...

in the "coquettes", tribe

Lesbiini Lesbiini is one of the two tribes that make up the subfamily Lesbiinae in the hummingbird family Trochilidae. The other tribe is Heliantheini (brilliants). The informal name "coquettes" has been proposed for this group as the largest genus, ''L ...

of subfamily

Lesbiinae Lesbiinae is one of the six subfamily, subfamilies that make up the hummingbird family (biology), family Trochilidae. The subfamily is divided into two Tribe (biology), tribes: Heliantheini ("brilliants") containing 14 genera and Lesbiini ("coqu ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Sierra Nevada de Santa Marta The Sierra Nevada de Santa Marta (English: ''Snow-Covered Mountain Range of Saint Martha'') is an isolated mountain range in northern Colombia, separate from the Andes range that runs through the north of the country. Reaching an elevation of ...

of northern

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

.HBW and BirdLife International (2020) ''Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world'' Version 5. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v5_Dec20.zip xls zipped 1 MBretrieved 27 May 2021

Taxonomy and systematics

The blue-bearded helmetcrest was formerly considered to be a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of what was known as the bearded helmetcrest (''Oxypogon guerinii''). The blue-bearded helmetcrest was promoted to species status when the bearded helmetcrest was split into four species based on a study of biometric and plumage data published in 2013. The nominate subspecies was renamed the

green-bearded helmetcrest The green-bearded helmetcrest (''Oxypogon guerinii'') is a species of hummingbird in the "coquettes", tribe Lesbiini of subfamily Lesbiinae. It is endemic to Colombia.HBW and BirdLife International (2020) ''Handbook of the Birds of the World ...

. The blue-bearded helmetcrest is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

Description

The blue-bearded helmetcrest is about long. It has a short straight bill. The male has a long black and white crest and a mostly dusky face with a buffy-white "collar". Its upperparts are olive green. Its throat has a thin white "beard" with a purplish blue center stripe. The rest of the underparts are dingy buff with olive spots that blends to buffy white on the undertail

coverts A covert feather or tectrix on a bird is one of a set of feathers, called coverts (or ''tectrices''), which, as the name implies, cover other feathers. The coverts help to smooth airflow over the wings and tail. Ear coverts The ear coverts are sm ...

. The tail is moderately long and forked. The upper side of the central tail feathers is bronzy olive and the rest are white with reddish bronze fringes and tips, and the underside is cream with wide olive tips. The adult female is similar to the male but lacks the crest and beard, is overall duller, and has a white throat. Juveniles resemble the adult female but without the white throat.del Hoyo, J., N. Collar, G. M. Kirwan, C. J. Sharpe, and P. F. D. Boesman (2020). Blue-bearded Helmetcrest (''Oxypogon cyanolaemus''), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.bubhel1.01 retrieved February 25, 2022

Distribution and habitat

The blue-bearded helmetcrest is found only in the isolated Sierra Nevada de Santa Marta of northern Colombia. It inhabits ''

páramo Páramo () can refer to a variety of alpine tundra ecosystems located in the Andes Mountain Range, South America. Some ecologists describe the páramo broadly as "all high, tropical, montane vegetation above the continuous timberline". A narrower ...

'' grasslands at elevations between .

Behavior

Movement

Nothing is known about the blue-bearded helmetcrest's movements, if any.

Feeding

Little is known about the blue-bearded helmetcrest's diet or feeding method. It has been observed feeding on nectar at a few species of flowering herbs and shrubs, both by hovering and by clinging to the flowers. Its primary food source appears to be '' Libanothamnus occultus''.

Breeding

Nothing is known about the blue-bearded helmetcrest's breeding

phenology Phenology is the study of periodic events in biological life cycles and how these are influenced by seasonality, seasonal and interannual variations in climate, as well as environmental factor, habitat factors (such as elevation). Examples includ ...

Vocalization

As of February 2022,

Xeno-canto xeno-canto is a citizen science project and Information repository, repository in which volunteers record, upload and annotate recordings of Bird vocalization, birdsong and bird calls. Since it began in 2005, it has collected over 575,000 sound r ...

had two recordings of blue-bearded helmetcrest vocalizations and Cornell University's

Macaulay Library The Macaulay Library is the world's largest archive of animal sounds. It includes more than 33 million photographs, 1.2 million audio recordings, and over two hundred thousand videos covering 96 percent of the world's bird species. There are an ever ...

had 13.

Status

The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed the blue-bearded helmetcrest as Critically Endangered. Its population is estimated at fewer than 250 mature individuals and is believed to be declining. The species was known only from 62 museum specimens with the most recent record in 1946. Surveys during 1999-2003 failed to detect the species. Brief surveys in February 2007 and December 2011 also failed to detect the species. In March 2015, the blue-bearded helmetcrest was rediscovered by researchers from the foundation ProAves while documenting fires set by local farmers. Though the species' entire range is nominally protected in Sierra Nevada de Santa Marta National Park, Indigenous people regularly burn the ''páramo'' to produced cattle pasture and collect ''Libanothamnus occultus'' for firewood.ProAves ' Retrieved 18 March 2015.

References

{{Taxonbar, from=Q17517273

blue-bearded helmetcrest The blue-bearded helmetcrest (''Oxypogon cyanolaemus'') is a Critically Endangered species of hummingbird in the "coquettes", tribe Lesbiini of subfamily Lesbiinae. It is endemic to the Sierra Nevada de Santa Marta of northern Colombia.HBW and ...

Birds of the Sierra Nevada de Santa Marta Endemic birds of Colombia Critically endangered animals Critically endangered biota of South America