[5][6] Adults of both sexes show an iridescent green back, white eye ring and a rounded black tail projecting beyond their wing tips, from which their name was inspired.

This type of wing beat has a sound that ranges from 35 to 100 Hz, and both sexes are able to produce it for communication.

[9] The broad-tailed hummingbird, Selasphorus platycercus, is a member of the order Apodiformes, in the family Trochilidae.

[10][11][12] This genus is characterized by hummingbirds with a plumage containing rufous coloration and a neck gorget of orange to purple in males.

[3][7] Its breeding habitat is mainly in subalpine meadows, foothills, montane valleys, and stands of aspen or spruce.

[16] The specific migratory route used by the broad-tailed hummingbird remains unknown, although migrating populations winter in southern Mexico or Guatemala and return to their breeding area in spring.

[6][14][18] Some populations of the broad-tailed hummingbird in southern Mexico and Guatemala do not migrate, a variation in behavior called "sedentary".

[19] These types of flower are characterized by high nectar production and red corollas with a tubular shape, such as Aquilegia elegantula.

[19] The range of breeding locations appear to be from central Montana in the north to Guatemala in the south.

[4] Although broad-tailed hummingbirds have been seen in British Columbia, these birds appear to be accidental migrants, with no evidence for breeding at such northern latitudes.