Blue-chested Hummingbird Polyerata amabilis Scientific name definitions

Blue-chested Hummingbirds inhabit the edges of humid and wet forests, second growth woodlands, thickets, plantations, gardens with flowering trees, and riparian areas. They seldom spend time in the forest interior and most often forage individually at low flowers around forest borders. These hummingbirds feed by visiting scattered flowers, defending floral territories, or gleaning insects. During the breeding season, males congregate in casual groups and sing together in the undergrowth, and following the breeding or flowering seasons, some birds migrate short distances. Males and females have straight bills and bronzy-green or maroonish tails. Males have sparkling green crowns with a violet blue lower throat and chest. The throats of females twinkle with blue spots.

7–11 cm; male 4–4·8 g (1 Robbins, M. B., T. A. Parker, and S. E. Allen (1985). The avifauna of Cerro Pirre, Darién, eastern Panama. Ornithological Monographs 36:198–232. Close ), female 3·8–4 g. Male has straight, mid-length, blackish bill, mandible basally reddish; crown and malar area glittering green with slight bluish tinge; upperparts and flanks dull green to bronze-green; chin centrally bronzy; lower throat and breast with violet-blue patch and greyish-edged discs; lower belly greyish brown; undertail-coverts with brownish centres; uppertail-coverts and tail bronze-green, rarely dull green, with some purplish reflections in tail-coverts and median rectrices; outer rectrices becoming blackish. Female lacks glittering crown; instead of distinct throat patch has scattered turquoise to bluish feathers with broad whitish margins; belly paler; rectrices with greyish tips. Juvenile resembles female in throat coloration but more greyish in underparts; juvenile male has dark green chin, throat with 15–30 bluish feathers, some glittering green feathers on crown and outer rectrices show small or no grey tips; and juvenile female has pale grey chin with green spots, throat shows 0–2 turquoise-blue feathers, crown dull green, and outer rectrices have grey tips.

NE Nicaragua S (on Caribbean slope) to NC Colombia and S to Ecuador W of Andes (S to El Oro); possibly SE Honduras. Precise limits of range at N & S extremes, and perhaps elsewhere, uncertain.

Inhabits forests edges, open woodland, thickets, second growth, clearings, riparian vegetation, plantations, etc.; visits gardens with flowering trees. Generally commoner in open areas; avoids interior of dense forest. Occurs from sea-level to 1400 m (latter elevation solely reached in Magdalena Valley of Colombia); normally below 500 m and infrequent above 1000 m; in W Ecuador, mainly found below 300 m, with single record at 1200 m.

Short-distance migrant; movements partially correlated with flowering period. Seasonal movements appear erratic, as individuals suddenly appear or disappear in certain places. May occur at higher altitudes after breeding season.

Forages for nectar, usually in lower strata at herbs such as Heliconia and shrubs; occasionally higher up in middle strata. In Colombia, recorded at diverse tree species, including Inga, Bravasia and Hamelia; in Panama also Psidium guajava. Also regularly takes insects, e.g. tiny dipterans, ants and other small hymenopterans, from foliage. Feeds by trap-lining or defends feeding territories that are different from those established during courtship, especially when foraging at nectar-poor resources like Warscewiczia trees; is dominated by larger hummingbirs such as Chalybura and Thalurania.

Song quite variable, typically a long series of strident squeaky notes, e.g. “tsip-tsew-tsew-tseek-tsew ...” or a simpler “tseek-tseek-tseek-tseek …”. Calls include a metallic “tsink” and a short “tsit”. Also a descending twitter during social interactions. Males gather at well-scattered leks.

In Costa Rica, nesting starts with dry season from Dec to May; similar season assumed for Panama and Colombia (birds in breeding condition collected in latter country between Feb and May). Cup-shaped nest on horizontal, leafy branch, in bush or small tree 2–5 m above ground; fixed with light-coloured plant fibres and cobweb; inside sometimes covered with seed-down and brown fern scales, outside with lichen and moss. Clutch two white eggs; incubation by female; chick pinkish, with sparse buff dorsal down; no data exist on incubation and fledging periods.

Not globally threatened (Least Concern). CITES II. Relatively common, at least locally, in most parts of range. One of the commonest trochilids in the Canal Zone of Panama. In NW Ecuador generally uncommon and outnumbered by P. rosenbergi.