The Wire-crested Thorntail (Discosura popelairii) is a hummingbird which occurs in Colombia, Ecuador and Peru.

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.

These birds require frequent feeding while active during the day and become torpid at night to conserve energy.