The bronze-tailed thornbill (''Chalcostigma heteropogon'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

hummingbird Hummingbirds are birds native to the Americas and comprise the Family (biology), biological family Trochilidae. With approximately 366 species and 113 genus, genera, they occur from Alaska to Tierra del Fuego, but most species are found in Cen ...

in the "coquettes", tribe

Lesbiini Lesbiini is one of the two Tribe (biology), tribes that make up the subfamily Lesbiinae in the hummingbird family (biology), family Trochilidae. The other tribe is Heliantheini (brilliants). The informal name "coquettes" has been proposed for th ...

of subfamily

Lesbiinae Lesbiinae is one of the six subfamilies that make up the hummingbird family Trochilidae. The subfamily is divided into two tribes: Heliantheini ("brilliants") containing 14 genera and Lesbiini ("coquettes") containing 18 genera. Phylogeny A mol ...

. It is found in

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

and

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

.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 taxonomy of genus ''Chalcostigma'' is unsettled. The South American Classification Committee (SACC) of the

American Ornithological Society The American Ornithological Society (AOS) is an ornithological organization based in the United States. The society was formed in October 2016 by the merger of the American Ornithologists' Union (AOU) and the Cooper Ornithological Society. Its ...

is considering a proposal to merge the genus into '' Oxypogon''. The bronze-tailed thornbill 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 "unisp ...

Description

The bronze-tailed thornbill is long and weighs . Both sexes have a short straight black bill. Adults are generally bottle green overall, with coppery red uppertail

coverts A covert feather or tectrix on a bird is one of a set of feathers, called coverts (or ''tectrices''), which cover other feathers. The coverts help to smooth airflow over the wings and tail. Ear coverts The ear coverts are small feathers behind t ...

and a forked olive green tail. Adult males have a narrow

gorget A gorget ( ; ) was a band of linen wrapped around a woman's neck and head in the English medieval clothing, medieval period or the lower part of a simple chaperon (headgear), chaperon hood. The term later described a steel or leather Collar (c ...

that is emerald green under the chin and transitions to pink at the bottom. Adult females are similar but the gorget is paler green and does not have the pink "beard"; in addition their outer tail feathers have pale tips. Juveniles resemble adult females with the addition of a mahogany red crown.Heindl, M. and P. F. D. Boesman (2020). Bronze-tailed Thornbill (''Chalcostigma heteropogon''), 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.brttho1.01 retrieved February 24, 2022

Distribution and habitat

The bronze-tailed thornbill is found from the Tamá Massif of extreme western Venezuela through the Eastern Andes of Colombia as far south as

Cundinamarca Department Department of Cundinamarca (, ) is one of the departments of Colombia. Its area covers (not including the Capital District) and it has a population of 2,919,060 as of 2018. It was created on August 5, 1886, under the constitutional terms pre ...

. It inhabits steep rocky slopes within semi-arid to humid

páramo Páramo () may 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 and also the edges 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, up to above sea level. It is distributed from Venezuela to Patagonia. In Peru, plants in the ...

'' and other stunted woodland. In elevation it ranges between .

Behavior

Movement

The bronze-tailed thornbill is thought to be sedentary, but it possibly makes seasonal elevational movements.

Feeding

The bronze-tailed thornbill feeds on nectar from a variety of flowers and shrubs. It forages by clinging to flowers or hovering, and not on the ground like some others of its genus. Both sexes are aggessive and defend patches of flowers. The species also gleans insects from vegetation and sallies to catch them on the wing.

Breeding

The bronze-tailed thornbill's breeding season is thought to span from September to January but may extend further at either end. As is typical of hummingbirds, the female alone incubates the two white eggs. Nothing else has been documented about its breeding

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

Vocalization

The bronze-tailed thornbill makes "a dull short 'tzk'" call; other vocalizations if any are not known.

Status

The

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

has assessed the bronze-tailed thornbill as being of Least Concern. However, it has a restricted range and its population size is unknown and believed to be decreasing. It occurs in some protected areas, and "the altitude and inhospitable climate of the region...offer some protection against intrusion by man." However, ''Polylepis'' woodlands are degraded over much of its range.

References

{{Taxonbar, from=Q928399 bronze-tailed thornbill Birds of the Colombian Andes bronze-tailed thornbill Taxonomy articles created by Polbot