The black-backed thornbill (''Ramphomicron dorsale'') is an

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

species of

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

endemic Endemism is the state of a species being found only 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 foun ...

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 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 ...

.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 black-backed 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 ...

. It shares its genus with the

purple-backed thornbill The purple-backed thornbill (''Ramphomicron microrhynchum'') is a species of hummingbird in the "coquettes", tribe Lesbiini of subfamily Lesbiinae. It is found in Bolivia, Colombia, Ecuador, Peru, and Venezuela.HBW and BirdLife International (2 ...

(''R. microrhynchum'').

Description

The black-backed thornbill is long and weighs about . Both sexes have a very short black bill; the male's is slightly decurved. The male's upperparts are velvety black with purplish 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 white spot behind the eye. Their

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 ...

is olive green and the rest of the underparts are a mix of dark gray and rufous with green dots. The tail is moderately long, deeply forked, and purplish black. Females have shining grass green upperparts, and like the male, purplish uppertail

and a white spot behind the eye. Their underparts are buffy white with green dots. The tail is shorter than the male's and the outer pair of feathers have white tips.Züchner, T. and P. F. D. Boesman (2020). Black-backed Thornbill (''Ramphomicron dorsale''), 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.blbtho1.01 retrieved 23 February 2022

Distribution and habitat

The black-backed thornbill is restricted to the isolated Sierra Nevada de Santa Marta in far northern Colombia, where it inhabits the edges of humid and

elfin forest A "natural National Park in the Philippines, a UNESCO World Heritage Site file:Mount Kemiri (8187817161).jpg, An elfin forest in Sumatra's Gunung Leuser National Park Dwarf forest, elfin forest, or pygmy forest is an uncommon ecosystem feat ...

and also ''

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 ...

''. In elevation it ranges from as high as the

snowline The climatic snow line is the boundary between a snow-covered and snow-free surface. The actual snow line may adjust seasonally, and be either significantly higher in elevation, or lower. The permanent snow line is the level above which snow wil ...

at about .

Behavior

Movement

The black-backed thornbill moves to lower elevations in May and Jun.

Feeding

The black-backed thornbill forages for nectar at any height from the ground to the canopy. It has been recorded taking nectar from the flowers of

Ericaceae The Ericaceae () are a Family (biology), family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with about 4,250 known species spread acros ...

, Lobeliaceae,

Melastomataceae Melastomataceae () is a family of dicotyledonous flowering plants found mostly in the tropics (two-thirds of the genera are from the New World tropics) comprising c. 175 genera and c. 5115 known species. Melastomes are annual or perennial herbs ...

, and

Rubiaceae Rubiaceae () is a family (biology), family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with Petiole ( ...

, and more specifically flowers of genera ''

Erythrina ''Erythrina'' is a genus of plants in the pea family, Fabaceae. It contains about 130 species, which are distributed in tropical and subtropical regions worldwide. They are trees, with the larger species growing up to in height. These species ...

'', '' Puya'', and ''

Salvia ''Salvia'' () is the largest genus of plants in the sage family Lamiaceae, with just under 1,000 species of shrubs, Herbaceous plant, herbaceous Perennial plant, perennials, and Annual plant, annuals. Within the Lamiaceae, ''Salvia'' is part o ...

''. It collects nectar while hovering and also by clinging to the flower. In addition it feeds on insects caught on the wing and gleaned from flowers.

Breeding

Nothing is known about the black-backed thornbill's 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 black-backed thornbill's calls include "a short dry rattle 'trrr'...a long descending rattle...'tsee-tttrrrrrrrr-tsee', ndsingle 'tsee' notes."

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 black-backed thornbill as Endangered. It has a very limited range; its population size is not known and is believed to be decreasing. Its habitat is under severe human pressure for conversion to agriculture and grazing. A small part of its range is protected in a national park.

References

{{Taxonbar, from=Q1269109 black-backed thornbill Birds of the Sierra Nevada de Santa Marta Endemic birds of Colombia black-backed thornbill black-backed thornbill black-backed thornbill Taxonomy articles created by Polbot