This species is one of the smallest birds on Earth, with a mature weight of around 2.5 g (0.088 oz). Males measure from 10.5 to 12 cm (4.1 to 4.7 in) in length, against the females' length of around 6.5 to 7.5 cm (2.6 to 3.0 in) long. The male of the eastern slopes of the northern Andes has elongated tail feathers that curve outward and taper from a broad base to a slender tip. The outermost is longest and each successive feather toward the center is shorter. All are steel-blue with white shafts, making a most striking and curious display when spread. The bird has a crest of brilliant green feathers. These birds feed on nectar from flowers using a long extendable tongue, or catch insects on the wing. Learn more about Wire-Crested Thorntail