The white-bearded helmetcrest (''Oxypogon lindenii'') is a 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 northwestern

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

.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 white-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 white-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 white-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 white-bearded helmetcrest is about long and weighs about . It has a short straight bill. The adult male has a long black and white crest and a mostly black face with a wide white "collar". Its upperparts are bronzy green with a slight gray scaly appearance. It has a long thin white "beard". The rest of the underparts are dingy gray with green spots. The tail is moderately long and forked. The upper side of its central feathers are olive green and the rest dusky; the underside of the feathers are maroon with white shafts and some narrow white at the base. The adult female is similar to the male but lacks the crest and beard, and its underparts are dull white with dense greenish brown spots. Juveniles are not well studied but are believed to resemble the adult female.del Hoyo, J., N. Collar, C. J. Sharpe, G. M. Kirwan, and P. F. D. Boesman (2020). White-bearded Helmetcrest (''Oxypogon lindenii''), 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.whbhel1.01 retrieved February 26, 2022

Distribution and habitat

The white-bearded helmetcrest is found only in the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

of northwestern Venezuela, in Mérida and Trujillo states. It inhabits humid ''

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 ...

'', especially that with ''

Espeletia ''Espeletia'', commonly known as 'frailejones' ("big monks"), is a genus of perennial subshrubs, in the family Asteraceae. The genus, which is native mainly to Colombia, Venezuela and Ecuador, was first formally described in 1808. The genus was ...

'' vegetation. It also sometimes occurs at the edge of ''

Polylepis ''Polylepis'' is a genus comprising 28 recognised shrub and tree species, that are endemic to the mid- and high-elevation regions of the tropical Andes. This group is unique in the rose family in that it is predominantly wind-pollinated. They are ...

'' woodlands. Females often occur in gorges while males tend to remain in more open landscapes. In elevation the species ranges between though there is at least one record as low as .

Behavior

Movement

The white-bearded helmetcrest migrates from the high ''páramo'' in the wet season to lower elevations in the dry.

Feeding

The white-bearded helmetcrest feeds on nectar; it especially favors '' Espeletia schultzii'' and ''

Castilleja ''Castilleja'', commonly known as paintbrush, Indian paintbrush, or prairie-fire, is a genus of about 200 species of annual and perennial herbaceous plants native to the west of the Americas from Alaska south to the Andes, northern Asia, and one ...

fissifolia''. It nectars by clinging to flowers rather than hovering. It also feeds on insects and their larvae. It catches insects on the ground or by jumping or

hawking Hawking may refer to: People * Stephen Hawking (1942–2018), English theoretical physicist and cosmologist *Hawking (surname), a family name (including a list of other persons with the name) Film * ''Hawking'' (2004 film), about Stephen Haw ...

from the ground or a perch. It picks larvae from vegetation.

Breeding

The white-bearded helmetcrest's breeding season is tied to the flowering of ''Espeletia'' and is usually between June and November. It makes a large nest of ''Espeletia'' fibers in cavities or below overhangs where it is protected from sun and rain. The clutch size it two eggs; the female incubates for 21 to 23 days and fledging occurs 35 to 38 days after hatch.

Vocalization

The white-bearded helmetcrest's song is "a repeated, high-pitched, slightly buzzy, single note 'tzee' or 'peek'" that it sings repeatedly from a perch on a small shrub during the breeding season.

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 white-bearded helmetcrest as being of Least Concern. It has a very small range and its population size is not known and believed to be decreasing. Thought it is considered very common and occurs in two national parks, overgrazing is a problem even in them.

References

{{Taxonbar, from=Q17517258 white-bearded helmetcrest Birds of the Venezuelan Andes Endemic birds of Venezuela white-bearded helmetcrest