The Buff-tailed Coronet is a hummingbird of Andean montane forest. Buff or rufous edges on its tail feathers are distinctive, and it feeds on nectar and small prey.
The upperparts are metallic green and the underparts lighter green or grayish green. Its tail feathers have buff or rufous edges, and there is a white spot behind the eye.
It takes nectar from flowering plants and also eats small insects and spiders. It may defend feeding areas from other hummingbirds and is described as an agile, acrobatic flier.
An extinction-risk assessment has not been added yet.