The peg-billed finch (''Acanthidops bairdi'') is a

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by t ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

endemic to the highlands of

Costa Rica Costa Rica (, ; ; literally "Rich Coast"), officially the Republic of Costa Rica ( es, República de Costa Rica), is a country in the Central American region of North America, bordered by Nicaragua to the north, the Caribbean Sea to the no ...

and western

Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos ...

. Despite its name, it is not a true

finch The true finches are small to medium-sized passerine birds in the family Fringillidae. Finches have stout conical bills adapted for eating seeds and nuts and often have colourful plumage. They occupy a great range of habitats where they are usua ...

, but now recognized as a member of the

tanager The tanagers (singular ) comprise the bird family Thraupidae, in the order Passeriformes. The family has a Neotropical distribution and is the second-largest family of birds. It represents about 4% of all avian species and 12% of the Neotropica ...

family (Thraupidae), after being long placed in the

Emberizidae The buntings are a group of Old World passerine birds forming the genus ''Emberiza'', the only genus in the family Emberizidae. The family contains 45 species. They are seed-eating birds with stubby, conical bills. Taxonomy The family Emberizid ...

. It is the only member of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Acanthidops''. The scientific name commemorates the American ornithologist

Spencer Fullerton Baird Spencer Fullerton Baird (; February 3, 1823 – August 19, 1887) was an American naturalist, ornithologist, ichthyologist, Herpetology, herpetologist, and museum curator. Baird was the first curator to be named at the Smithsonian Institution. He ...

Taxonomy

The peg-billed finch was formally described in 1882 by the American ornithologist

Robert Ridgway Robert Ridgway (July 2, 1850 – March 25, 1929) was an American ornithologist specializing in systematics. He was appointed in 1880 by Spencer Fullerton Baird, secretary of the Smithsonian Institution, to be the first full-time curator of bird ...

from a specimen collected near the

Irazú Volcano The Irazú Volcano ( es, Volcán Irazú) is an active volcano in Costa Rica, situated in the Cordillera Central close to the city of Cartago. The name could come from either the combination of "ara" (point) and "tzu" (thunder) or a corruptio ...

in Costa Rica. To accommodate the new species Ridgway introduced the genus ''Acanthidops'' and coined the

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''Acanthidops bairdi''. The genus name combines the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

''akanthis'' meaning "spiky" with ''ōps'' meaning "face". The specific epithet honours the American naturalist

. No

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 ...

are recognised.

Description

The peg-billed finch is a long-tailed species, 13.5 cm long and weighing 16 g. It has a distinctive long upturned bill with a black upper mandible and yellow lower mandible. The adult male is slate grey, becoming paler on the belly. The female is olive-brown above, becoming paler below and with a grey tinge to the head and upper back. She has bright cinnamon wing bars and buff supercilia. Young birds are similar to the female, but have paler plumage and weaker wing bars. It has a dry call, and the male's song consists of high whistled notes ending with a buzz, .

Habitat

This is an uncommon bird at the edges and clearings of mountain forests, and in scrubby second growth,

bamboo Bamboos are a diverse group of evergreen perennial flowering plants making up the subfamily Bambusoideae of the grass family Poaceae. Giant bamboos are the largest members of the grass family. The origin of the word "bamboo" is uncertain, bu ...

clumps, and bushy pastures from 1500 m altitude to the timberline. In the wet season it can descend to 1200 m altitude. Its numbers have reported to be high when the bamboo is flowering on favoured sites such as

Cerro de la Muerte Cerro de la Muerte is a mountain peak of a massif in Costa Rica, it is located within the Tapantí — Cerro de la Muerte Massif National Park, and is the highest point on the Pan-American Highway. Toponymy Its name means "Mountain of Death", " ...

Behaviour

The finch is seen singly, in pairs, family groups or in

mixed-species feeding flock A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species that join each other and move together while foraging. These ar ...

s with other small birds such as

warblers Various Passeriformes (perching birds) are commonly referred to as warblers. They are not necessarily closely related to one another, but share some characteristics, such as being fairly small, vocal, and insectivorous. Sylvioid warblers Th ...

Breeding

The nest, built by the female, is a cup of plant material into which she lays typically four eggs. The female alone incubates for 12–14 days to hatching.

Feeding

It feeds on

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s and

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

s, grass and bamboo seeds. It will also squeeze nectar from flowers and juice from berries.

References

Sources

* Stiles and Skutch, ''A guide to the birds of Costa Rica'', {{Taxonbar, from=Q738741

peg-billed finch The peg-billed finch (''Acanthidops bairdi'') is a passerine bird endemic to the highlands of Costa Rica and western Panama. Despite its name, it is not a true finch, but now recognized as a member of the tanager family (Thraupidae), after being ...

Birds of the Talamancan montane forests

Tanagers Taxa named by Robert Ridgway