Viridian Metaltail

The viridian metaltail (Metallura williami) is a species of hummingbird in the "coquettes", tribe Lesbiini of subfamily Lesbiinae. It is found in Colombia and Ecuador. == Taxonomy and systematics == The viridian metaltail has these four recognized subspecies: M. w. recisa Wetmore, 1970 M. w. williami (Delattre & Bourcier), 1846 M. w. primolina Bourcier, 1853 M. w. atrigularis Salvin, 1893 Subspecies M. w. primolina and M. w. atrigularis were at one time each treated as separate species but since at least the mid 20th century have been considered subspecies. However, in the early 21st century atrigularis was again suggested as a possible separate species. == Description == The viridian metaltail is 11 to 12 cm (4.3 to 4.7 in) long and weighs 4.1 to 5.3 g (0.14 to 0.19 oz). It has a medium length, straight, black bill. The adult male of the nominate subspecies has bottle green upper- and underparts. Its gorget is glittering bottle green and it has a purplish blue, slightly forked, tail. The adult female's upperparts are also bottle green. Its throat, breast, and belly are mottled green and white and its outer tail feathers have whitish tips on their underside. Juveniles are similar to adult…