Blue-capped puffleg

The blue-capped puffleg is monotypic.[3]

The blue-capped puffleg is 9 to 13 cm (3.5 to 5.1 in) long and weighs 4.0 to 4.5 g (0.14 to 0.16 oz). It has a straight black bill. The male has dark green upperparts with a dark glittering blue forehead. Its underparts are mostly golden green, with a bluish green lower breast and shining purplish blue undertail coverts. Its leg puffs are white. The tail is long, forked, and blue-black. The female's upperparts are also dark green but without the blue forehead. Its throat, breast, and belly are bright cinnamon-buff and the undertail coverts have pale buff fringes. The female's tail is less deeply forked than the male's.[5]

The blue-capped puffleg is the southernmost representative of its genus. It is found from Bolivia's La Paz and Cochabamba departments south into northwestern Argentina's Salta and Tucumán provinces. It generally inhabits humid slopes of grass and dense shrubs and the edges of cloudforest. In Argentina it also occurs in somewhat dryer landscapes. In elevation it ranges from 1,500 to 3,400 m (4,900 to 11,200 ft) but is most common between 2,000 to 2,500 m (6,600 to 8,200 ft).[5]

The IUCN has assessed the blue-capped puffleg as being of Least Concern. Though its population size is not known it is believed to be stable, and no specific threats have been identified.[1] It is considered overall to be rare but locally common and occurs in two national parks in Argentina.[5]