Small hummingbird with short, black bill and completely white underparts; found in savannas, dry forests, and disturbed habitats. Hovers at flowers like other hummingbirds. Males sing a hard, rattling trill from exposed perches beneath forest canopy. Most similar to Plain-bellied and Versicolored Emeralds, but has shorter, entirely black bill; where these species occur together, White-chested may not be safely separable from them if not seen well.