Buff-tailed Coronet

The buff-tailed coronet is 11 to 12 cm (4.3 to 4.7 in) long and weighs 7.3 to 8.8 g (0.26 to 0.31 oz). Both sexes have a short, straight, black bill and a small white spot behind the eye. Males of the nominate subspecies are mostly shining green, with a buff belly accented by green spots. The underwing coverts are cinnamon and show in flight. The central tail feathers are bronzy and the rest are buff with bronze tips and edges. It has small white tufts on the legs. The nominate female has more buff on the underparts and the bronze of the tail is less extensive. The buff parts of both sexes of B. f. tinochlora have a cinnamon cast and there is more bronze on the tail feathers' tips.

The nominate subspecies of buff-tailed coronet is found from the Andes of western Venezuela's Mérida state south and west through all three Andean ranges of Colombia. B. f. tinochlora is found from southwestern Colombia south along the west slope of the Andes as far as Cotopaxi Province in central Ecuador and also in a few places on Ecuador's eastern Andean slope. The species inhabits the interior and edges of humid to wet montane forest, cloudforest, and elfin forest. It also occurs in more open shrubby landscapes. In elevation it ranges from 2,000 to 3,500 m (6,560 to 11,480 ft).

The buff-tailed coronet is highly territorial, though it may share feeding at a flowering tree with other hummingbirds. It typically forages in the mid-story but also feeds in the canopy. Its main nectar sources are in genera Cavendishia, Palicourea, Disterigma, and Huilaea. It feeds by clinging to the flower, holding its wings open for a second or two after landing. In addition to nectar, it captures small insects by hawking from a perch.