Mangrove hummingbird

The mangrove hummingbird (Chrysuronia boucardi) is an Endangered species of hummingbird in the "emeralds", tribe Trochilini of subfamily Trochilinae. It is endemic to Costa Rica.

The mangrove hummingbird is 9.5 to 11 cm (3.7 to 4.3 in) long and weighs about 4.5 g (0.16 oz). Both sexes have a medium length bill, slightly decurved, with a black maxilla and a reddish mandible with a dusky tip. Adult males have golden to bronze-green upperparts and flanks. Their chin, throat, and breast are glittering bluish green with white bars near the end of the chin feathers. Their belly is whitish with bronze-green sides and their undertail coverts are white. The slightly forked tail is bronzy green; the outer feathers have blackish outer edges and tips. Adult females are similar to males, but with less green on the underparts and grayish tips on the outermost tail feathers. Immature birds resemble adult females but are more grayish below.

One form of vocalization has been described in words as a "soft djt sound that is rapid and given in a descending twitter."