White-bellied Mountaingem

The White-bellied Mountaingem, known scientifically as Lampornis hemileucus, is a diminutive and enchanting species of hummingbird. This avian jewel measures a mere 10 to 11 centimeters in length, with males slightly heavier at around 6.2 grams compared to the females' 5.1 grams.

Identification Tips

Both sexes of the White-bellied Mountaingem possess a medium-length black bill and exhibit a distinctive long white stripe behind the eye, complemented by pinkish feet. The adult male is adorned with a glittering green face and crown, bronzy green upperparts, and bronzy uppertail coverts. The tail feathers are bronzy with dusky gray bands near the tips. A striking blue-violet gorget graces the male's throat, while the underparts are predominantly white with green speckles along the sides. The adult female is similar in appearance but with less luster on the face and crown, and a white throat speckled with green. Juveniles of both sexes display rusty fringes on their green feathers, with males sporting a dull bronze gorget.

Habitat

This species thrives in the canopy of cool, very wet subtropical forests, and can also be found at the shrub level at forest edges, gaps, and clearings. It tends to avoid secondary forests and semi-open landscapes.

Distribution

The White-bellied Mountaingem graces the Caribbean slope from north-central Costa Rica, extending south and east into western Panama as far as Veraguas Province. It is also found locally on the Pacific slope in Panama.

Behaviour

In Costa Rica, the White-bellied Mountaingem breeds at elevations between 700 and 1,400 meters and descends to 400 to 600 meters post-breeding. Males are known to be quite aggressive when feeding, often dominating other hummingbirds at flowering epiphytes.

Song & Calls

The song of the White-bellied Mountaingem is a complex medley of squeaks, trills both dry and liquid, and sputtering notes. When in pursuit, it emits squeaky sputtering trills, and its calls include a nasal 'deep' and rattling sequences 'de-de-drrrrr'.

Breeding

Breeding season for this species in Costa Rica spans from August to March. However, details of its nesting and specific breeding behaviors remain a mystery.

Diet and Feeding

The White-bellied Mountaingem has a predilection for nectar from flowering trees, shrubs, and particularly favors epiphytes from the family Ericaceae and genus Columnea. It also supplements its diet with insects caught in flight or gleaned from foliage by the females.

Conservation Status

The IUCN has classified the White-bellied Mountaingem as Least Concern. Despite its somewhat restricted range, the species is locally common, and much of its habitat is intact, particularly within three national parks in Costa Rica.