Pufflegs are characteristic hummingbirds of high elevation, humid montane forest and forest edge in the Andes. Golden-breasted Puffleg is a relatively large species of Eriocnemis, and like other members of the genus has a large tuft of fluffy feathers on the lower tarsus. This species is well-named, as the glittering coppery color of the breast and sides of the neck contrasts with the glittering green of the rest of the body plumage. In this species, the sexes are very similar, if not the same, in plumage.
Golden-breasted Puffleg usually forages solitarily at flowering shrubs, and is aggressive in defending its food sources. Its natural habitat is subtropical or tropical moist montane forest. The pufflegs occur naturally in Argentina, Bolivia, Peru, Ecuador, Colombia and Venezuela - at elevations between 3,300 - 15,700 ft (1000 - 4800 m).
12–13 cm; 5·2–5·8 g. Male has straight, black bill; shining green above, more bronze-green on neck and rump; underparts glittering golden-green