Vervain hummingbird

The vervain hummingbird is perhaps the second-smallest bird in the world after the smallest, the bee hummingbird, though some other tiny ones are close to it in size. It is about 6 cm (2.4 in) long, including the 1 cm (0.39 in) bill, and weighs about 2 to 2.4 g (0.071 to 0.085 oz). The sexes are nearly alike but for their tails and the subspecies have only subtle plumage differences. All have a short, straight, dull black bill. Males are unique among hummingbirds by not having any iridescent feathering.

Males have dull metallic green uppersides that are almost black on the rump and uppertail coverts. The chin, throat, and chest are pale gray lightly spotted with darker gray; the belly and undertail coverts are dark metallic green. Its tail is entirely black and slightly forked. Females are dark metallic green to bluish green above and on the flanks. The throat is pale gray that darkens down the underparts to the vent area. The tail is rounded, not forked like the male's. The base of its central feathers are dark green and the rest of their length is black. The other tail feathers are black with varying amounts of white on their tips.