White-bellied Mountain-gems

White-bellied Mountain-gem (Oreopyra hemileucus) - Male
Hummingbird Information

The White-bellied Mountain-gem (Oreopyra hemileucus recently split from Lampornis) is a hummingbird with a very restricted range in south central America.


Distribution / Range

The White-bellied Mountain-gem occurs along the highlands on Caribbean slope of northeastern Costa Rica and western Panama.

They inhabit the foothills and mid-elevations of the Caribbean slope.


Alternate (Global) Names

Chinese: ?????? ... Czech: Kolibrík belostný, kolib?ík vyso?inný ... Danish: Hvidbuget Bjergjuvel ... Dutch: Witbuikjuweelkolibrie, Witbuik-juweelkolibrie ... German: Veilchenkehlnymphe, Weißbauchnymphe, Weissbauch-Nymphe ... Spanish: Colibrí Gorgivioleta, Colibrí Montañes Vientriblanco, Colibrí montañés vientriblanco, Gema de Vientre Blanco ... Finnish: Valkopilvikolibri ... French: Colibri à gorge lilas ... Italian: Gemma di montagna ventrebianco, Orogemma panciabianca ... Norwegian: Hvitbukjuvel ... Polish: malachicik bialobrzuchy, malachicik bia?obrzuchy ... Russian: ?????????? ?????????? ??????? ... Slovak: medovec bielobruchý ... Swedish: Vitbukad bergsjuvel

White-bellied Mountain-gem


White-bellied Mountain-gemDescription

The White-bellied Mountain-gem averages 4 inches (10.5 cm) in length (from top of the head to tip of the tail). The upper plumage is glossy green, while the plumage below is whitish, with some grey spotting at the sides. They have a whitish stripe from the eye down to the side of the neck (postocular eye stripe).

The male can be identified by the pale lilac throat patch (lacking in the female).


Nesting / Breeding

Hummingbirds are solitary in all aspects of life other than breeding; and the male's only involvement in the reproductive process is the actual mating with the female. They neither live nor migrate in flocks; and there is no pair bond for this species. Males court females by flying in a u-shaped pattern in front of them. He will separate from the female immediately after copulation. In all likelihood, the female also mates with several males. The males do not participate in choosing the nest location, building the nest or raising the chicks.

The female White-bellied Mountain-gem is responsible for building the cup-shaped nest out of plant fibers woven together and green moss on the outside for camouflage in a protected location in a shrub, bush or tree. She lines the nest with soft plant fibers, animal hair and feather down, and strengthens the structure with spider webbing and other sticky material, giving it an elastic quality to allow it to stretch to double its size as the chicks grow and need more room. The nest is typically found on a low, thin horizontal branch.

The average clutch consists of two white eggs, which she incubates alone, while the male defends his territory and the flowers he feeds on. The young are born blind, immobile and without any down.

White-bellied Mountain-gem The female alone protects and feeds the chicks with regurgitated food (mostly partially-digested insects since nectar is an insufficient source of protein for the growing chicks). The female pushes the food down the chicks' throats with her long bill directly into their stomachs.

As is the case with other hummingbird species, the chicks are brooded only the first week or two, and left alone even on cooler nights after about 12 days - probably due to the small nest size. The chicks leave the nest when they are about 7 - 10 days old.


Diet / Feeding

The White-bellied Mountain-gems primarily feed on nectar taken from a variety of brightly colored, scented small flowers of trees, herbs, shrubs and epiphytes. They favor flowers with the highest sugar content (often red-colored and tubular-shaped) and seek out, and aggressively protect, those areas containing flowers with high energy nectar.They use their long, extendible, straw-like tongues to retrieve the nectar while hovering with their tails cocked upward as they are licking at the nectar up to 13 times per second. Sometimes they may be seen hanging on the flower while feeding.

Many native and cultivated plants on whose flowers these birds feed heavily rely on them for pollination. The mostly tubular-shaped flowers actually exclude most bees and butterflies from feeding on them and, subsequently, from pollinating the plants.

White-bellied Mountain-gem (Oreopyra hemileucus) They may also visit local hummingbird feeders for some sugar water (also very rarely do so within their range), or drink out of bird baths or water fountains where they will either hover and sip water as it runs over the edge; or they will perch on the edge and drink - like all the other birds; however, they only remain still for a short moment.

They also take some small spiders and insects - important sources of protein particularly needed during the breeding season to ensure the proper development of their young. Insects are often caught in flight (hawking); snatched off leaves or branches, or are taken from spider webs.


Metabolism and Survival and Flight Adaptions - Amazing Facts

Species Research by Sibylle Johnson


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