The white-vented plumeleteer (Chalybura buffonii) is a species of hummingbird in the "emeralds", tribe Trochilini of subfamily Trochilinae.

[8] Males of the nominate subspecies C. b. buffonii have mostly dark metallic green upperparts with a bronzy tinge to the crown and coppery bronze uppertail coverts.

Males' central tail feathers are a deeper blue and females' undersides are a clearer gray.

C. b. aeneicauda males are a more golden-green below than the nominate and their central tail feathers are bright bronze-green to copper-bronze.

The subspecies differ somewhat in their requirements; only caeruleogaster and sometimes buffonii frequent the interior of wet forest.

[8] The white-vented plumeleteer forages for nectar at a wide variety of flowering plants from the understory almost to the canopy.

In addition to nectar it catches small arthropods by hawking from a perch, hovering, and hover-gleaning from vegetation and spider webs.

[8] The white-vented plumeleteer's breeding seasons vary across its range, including September in Panama, February to August in the Magdalena valley, June to November in the Eastern Andes, and perhaps year-round in parts of Venezuela.