About Eupherusa nigriventris Lawrence, 1868
Eupherusa nigriventris, commonly called the black-bellied hummingbird, measures 7 to 8 cm (2.8 to 3.1 in) in length and weighs approximately 3.0 to 3.5 g (0.11 to 0.12 oz). Males have a black breast and belly, which gives the species its English common name. Their forehead and face are also black, with green sides of the breast and white undertail coverts. Males have mostly bronze green upperparts, with narrow black edges on the crown feathers and dull bronze uppertail coverts. Their central tail feathers are dull black with a bronze gloss, while the outer tail feathers are white. Females have grayish white underparts with white undertail coverts, and metallic bronze green upperparts that are more bronze on the uppertail coverts. Both sexes molt after breeding, but males molt one to two months earlier than females. The black-bellied hummingbird ranges from Costa Rica into western Panama, occurring mostly on the Caribbean slope. It inhabits the edges and interior of humid montane forest at elevations between roughly 600 and 2,000 m (2,000 and 6,600 ft).
