The white-chested emerald (''Chrysuronia brevirostris'') is a

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 "emeralds", tribe Trochilini of subfamily Trochilinae. It is found in

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

the Guianas The Guianas, also spelled Guyanas or Guayanas, are a geographical region in north-eastern South America. Strictly, the term refers to the three Guianas: Guyana, Suriname, and French Guiana, formerly British, Dutch, and French Guiana respectiv ...

Trinidad Trinidad is the larger, more populous island of the Republic of Trinidad and Tobago, the country. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is the southernmost island in ...

, 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 (2021) Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 6. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6_Dec21.zip retrieved August 7, 2022

Taxonomy and systematics

The white-chested emerald's taxonomic history is complex. The species was previously known in succession as ''Amazilia chionopectus'', ''Agyrtria brevirostris'', and ''Amazilia brevirostris''. A

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study published in 2014 found that ''Amazilia'' was

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

. In the revised classification to create

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

genera, the white-chested emerald was moved by most taxonomic systems to '' Chrysuronia''.Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, J. A. Gerbracht, D. Lepage, B. L. Sullivan, and C. L. Wood. 2021. The eBird/Clements checklist of Birds of the World: v2021. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ Retrieved August 25, 2021 However,

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding i ...

's ''

Handbook of the Birds of the World The ''Handbook of the Birds of the World'' (HBW) is a multi-volume series produced by the Spanish publishing house Lynx Edicions in partnership with BirdLife International. It is the first handbook to cover every known living species of bird. ...

'' retains it in ''Amazilia''. The white-chested emerald has three subspecies, the

nominate Nomination is part of the process of selecting a candidate for either election to a public office, or the bestowing of an honor or award. A collection of nominees narrowed from the full list of candidates is a short list. Political office In th ...

''C. b. brevirostris'', ''C. b. chionopectus'', and ''C. b. orienticola''.

Description

The white-chested emerald is long. Males weigh about and females . Adults of both sexes of all subspecies have a short, straight, blackish bill and the sexes are almost alike in plumage. The nominate subspecies has iridescent turquoise-green crown and cheeks and shining bronze-green upperparts that become coppery on the rump. Its central tail feathers are coppery and the outer ones bronze to copperish with blackish bars near the end of their underside. Its underside from throat to belly is white with bronze-green sides and flanks. Its undertail

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 ...

are golden-green with white edges. The female differs from the male only by having grayish tips on the outer tail feathers. Juveniles resemble adult females with a yellowish to reddish base on their

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

.Weller, A.A. and P. F. D. Boesman (2021). White-chested Emerald (''Chrysuronia brevirostris''), version 1.1. 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.whceme1.01.1 retrieved September 20, 2022 Subspecies ''C. b. chionopectus'' is significantly larger than the other two subspecies but has the same plumage as the nominate. ''C. b. orienticola'' is similar to the nominate but has darker, more bronze colored, upperparts and flanks.

Distribution and habitat

The nominate subspecies of white-chested emerald is the most widespread. It is found in eastern Venezuela, Guyana, Suriname, and extreme northern Brazil's

Roraima Roraima ( ) is one of the 26 states of Brazil. Located in the country's North Region, it is the northernmost and most geographically and logistically isolated state in Brazil. It is bordered by the state of Pará to the southeast, Amazonas t ...

state. ''C. b. chionopectus'' occurs only on Trinidad and ''C. b. orienticola'' only in coastal French Guiana. The species inhabits a variety of landscapes including rainforest;

semi-deciduous Semi-deciduous or semi-evergreen is a botanical term which refers to plants that lose their foliage for a very short period, when old leaves fall off and new foliage growth is starting. This phenomenon occurs in tropical and sub-tropical wood ...

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, and secondary forests; scrublands; savanna; and some cultivated areas. ''C. b. chionopectus'' favors more open landscapes including cacao plantations. There are very few specimens or sightings of ''C. b. orienticola'', and all are from coastal areas.

Behavior

Movement

Most populations of white-chested emerald are thought to be sedentary but data are lacking.

Feeding

The white-chested emerald forages for nectar at a variety of flowering plants and trees; species in at least nine families are known to be sources. In addition to nectar it feeds on insects captured by hawking from a perch or by gleaning from vegetation.

Breeding

The white-chested emerald's breeding season includes at least December to April. It makes a cup nest of plant fibers with lichen on the outside and typically places it on a horizontal branch between above the ground. The female incubates the clutch of two eggs but the period is not known; fledging occurs about 20 days after hatch.

Vocalization

The white-chested emerald's song is variable but always "nasal and squeaky". Some typical phrases are described as "tsri-lee … tsri-lee ... tsri-lee", "tee-tink-tink-tink .. tsee-tink ... tee-tink-tink-tink … tsee-tink ...", or "teee-tjitjitjitjitji ..... teee-tjitjitjitjitji...".

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 white-chested emerald as being of Least Concern. It has a large range but its population size and trend are not known. It is one of the most common hummingbirds on Trinidad, but the mainland population has not been well studied and its abundance across its distribution is not known. ''C. b. orienticola'' is hardly known and appears to be very rare.

References

External links

* (for

Trinidad and Tobago Trinidad and Tobago, officially the Republic of Trinidad and Tobago, is the southernmost island country in the Caribbean, comprising the main islands of Trinidad and Tobago, along with several List of islands of Trinidad and Tobago, smaller i ...

)
White-chested Emerald photo gallery
VIREO {{Taxonbar, from=Q1273473 white-chested emerald Birds of Venezuela Birds of the Guiana Shield Birds of Trinidad and Tobago Hummingbird species of South America white-chested emerald Taxobox binomials not recognized by IUCN