The Snowy-bellied Hummingbird (Eupherusa poliocerca) is a small hummingbird found in Costa Rica and western Panama. With its glittering green upperparts and clean white underparts, it is a striking and unmistakable species.
Description
The adult male Snowy-bellied Hummingbird has brilliant, shining green upperparts from its bill to its tail. Its throat and breast are clean white, and its belly has variable amounts of white, from all white to heavily marked with green streaks. The flanks are also variably marked with green. The bill is long, straight and black. The tail is forked and steel blue above, black below. The female is similar but has greener underparts, heavier green streaking on the belly, and rounded rather than forked tail feathers. Juveniles resemble adult females but have buff edges to the feathers.
This hummingbird reaches a length of 9-10 cm (3.5-4 in) and a weight of 3-4 g (0.11-0.14 oz).
Voice
The voice of the Snowy-bellied Hummingbird is a thin, high-pitched, buzzy chip.
Distribution and Habitat
The Snowy-bellied Hummingbird is found along the Caribbean slopes of the cordilleras in Costa Rica and western Panama. Its habitats are cloud forests and rainforests at elevations of 900 to 2500 m (3000 to 8200 ft), mostly between 1500 and 2000 m (5000 to 6500 ft).
Behavior
The Snowy-bellied Hummingbird feeds on nectar taken from a variety of small flowers, including epiphytic Ericaceae and Gesneriaceae. It prefers to forage in the mid-levels and high canopy of the forest. It is territorial, with males defending flower-rich feeding territories from perches.
This species’ flight is slow and deliberate, with the wingbeats audible to human ears as a buzzing sound. In courtship displays, the male flies in U-shaped patterns before the female.
Reproduction
The breeding season for the Snowy-bellied Hummingbird is between March and June. The tiny cup-shaped nest is constructed by the female from plant fibers and other materials such as moss and lichens. It is placed on a low, thin branch or vine, 1 to 7 m above the ground.
The eggs are white and there are usually two in a clutch. Incubation is 15-19 days and the chicks fledge after about 20-26 days. The female alone builds the nest, incubates the eggs and cares for the young, while the male defends the territory.
Conservation Status
The Snowy-bellied Hummingbird has a relatively small range but is common within that range. Its population is suspected to be declining slightly due to habitat loss, but not at a rate that would warrant listing as threatened. The IUCN Red List categorizes its conservation status as Least Concern.
Fun Facts
– This hummingbird takes its name from the male’s snowy white underparts, contrasting sharply with its brilliant green back. The female is greener below.
– Like all hummingbirds, it can hover in still air and even fly backwards. This agile flight allows it to feed while hovering at nectar-bearing flowers.
– To conserve energy overnight, the Snowy-bellied Hummingbird enters a state of torpor where its metabolic rate and body temperature are reduced.
– The species was first described by Adolphe Boucard in 1891 based on a specimen from the Volcán de Chiriquí in Panama.
– While feeding, the wings of the Snowy-bellied Hummingbird beat up to 70 times per second. This allows the bird to float in one place while extracting nectar.
In summary, the beautiful Snowy-bellied Hummingbird is a tropical Central American species adapted to life in mountain cloud forests. With its striking green and white plumage and energetic flight, it is a jewel of these montane environments. Maintaining intact forests across its range will be crucial for the continued survival of this diminutive bird.