Green-tailed trainbearer

The green-tailed trainbearer (Lesbia nuna) is a species of hummingbird in the "coquettes", tribe Lesbiini of subfamily Lesbiinae. It is found in Bolivia, Colombia, Ecuador, Peru, and possibly Venezuela.

The male green-tailed trainbearer is 15.3 to 17 cm (6.0 to 6.7 in) long including the 10.6 to 13.6 cm (4.2 to 5.4 in) long tail. Females are about 11.6 cm (4.6 in) long including their 4.5 to 6.2 cm (1.8 to 2.4 in) long tail. The species weighs 3.1 to 4.3 g (0.11 to 0.15 oz). It has a short, straight, black bill. Males of the nominate subspecies are almost entirely glittering emerald green; the throat is iridescent emerald green and the lower belly grayish with green dots. Its tail is long, forked, and black with green tips to the feathers. The nominate female is similar but has white underparts with glittering green spots and a shorter tail. Juveniles are similar to the adult female but the male in addition has green spots on the throat.

Males of subspecies L. n. gouldii are similar to the nominate but smaller, with a shorter bill and more green on the tail. L. n. gracilis is also similar to the nominate but has a shorter and thicker bill and buffy undertail coverts with green spots. L. n. pallidiventris has a longer bill than the two subspecies above and has paler and less blue-green upperparts than the nominate. L. n. huallagae has a longer bill than pallidiventris that is still shorter than the nominate's; its plumage is somewhat bronzy green and the belly is paler than the nominate's. L. n. aureliae's plumage is rich golden bronze and it has a creamy buff belly.