The buff-tailed coronet (Boissonneaua flavescens) is a species of hummingbird in the 'Brilliants' tribe Heliantheini, within the subfamily Lesbiinae. It is found in Colombia, Ecuador, and Venezuela. == Taxonomy and systematics == The buff-tailed coronet shares genus Boissonneaua with two other coronets, the chestnut-breasted (B. matthewsii) and velvet-purple (B. jardini). It has two subspecies, the nominate B. f. flavescens and B. f. tinochlora. == Description == 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. == Distribution and…
