White-chested Emerald

Identificazione

The white-chested emerald is 9 to 10 cm (3.5 to 3.9 in) long. Males weigh about 4.6 g (0.16 oz) and females 4.4 g (0.16 oz). 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 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.<p>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.

Tassonomia

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 study published in 2014 found that Amazilia was polyphyletic. In the revised classification to create monophyletic genera, the white-chested emerald was moved by most taxonomic systems to Chrysuronia. However, BirdLife International's Handbook of the Birds of the World retains it in Amazilia. <p>The white-chested emerald has three subspecies, the nominate C. b. brevirostris, C. b. chionopectus, and C. b. orienticola.

Nome scientifico

Chrysuronia brevirostris

Autorità

(Lesson, RP, 1829)

Ordine

Apodiformi

Famiglia

Trochilidae

Genere

Chrysuronia

Areale e 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 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, gallery, 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.

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Tendenza della popolazione: stabile.

Tendenza della popolazione

stabile