The emerald-chinned hummingbird, Abeillia abeillei, is a diminutive and vibrant member of the "emeralds" tribe Trochilini. This species exhibits a striking metallic emerald green chin and upper throat, with males also featuring a velvety black to dusky metallic bronze green lower throat. The bird's upperparts are a metallic bronze green to greenish bronze, and its underparts are a deep brownish gray with a metallic sheen, except on the belly. Females are similar but lack the metallic throat, having pale gray underparts instead.
Adults of this species can be identified by their short, straight, dull black bill and the bold white spot behind the eye. The male's brilliant emerald green chin is a key distinguishing feature, along with the metallic gloss on their upperparts. Females, while lacking the metallic throat, have a similar overall structure and coloration with subtle differences in the underparts.
The emerald-chinned hummingbird is found in the interior and edges of humid evergreen montane forests and pine-evergreen forests. It prefers elevations ranging from 1,000 to 2,200 meters.
This species has a discontinuous range from Veracruz in southern Mexico through Guatemala into northern Honduras, with the subspecies A. a. aurea extending from southern Honduras into northern Nicaragua.
The emerald-chinned hummingbird's movements are not well documented. It is known to forage close to the ground, usually within cover, and males are known to defend clusters of flowers.
The song of the emerald-chinned hummingbird is a high, thin series of chipping sounds, while its foraging call is a liquid, rattling trill. When perched, it emits a sharp sii'ing sound.
Details on the breeding habits of the emerald-chinned hummingbird are scarce. It is reported to nest in Mexico during February and March, constructing a cup nest low in the forest understory. Incubation length and time to fledging remain unknown.
While the exact diet has not been detailed, this hummingbird is known to feed on the nectar of flowers from the Rubiaceae, Verbenaceae, and Oenotheraceae families. It also consumes small insects gleaned from flowers, leaves, and tree trunks while hovering.
The IUCN has classified the emerald-chinned hummingbird as Least Concern, although its population size is not known and is believed to be decreasing. In Mexico, it has "Special Protection" status due to threats from logging and habitat conversion for agriculture and livestock production.