The White-throated Swift is one of the frequent fliers of the bird world; only incubation and rest keep this bird out of the air. White-throated Swifts feed, drink, bathe and even mate while flying. During their lifespan, it is likely that many of these birds travel more than a million miles; their body form is one of the most highly evolved for flight. The White-throated Swift is the fastest North American swift; it's possible that it is among the fastest birds in the world. White-throated Swifts have been observed flying at an estimated 200 m.p.h. (320 km/h). The genus name Aeronautes is Greek for 'air sailor.'
I.D.: Sexes similar: black upperparts; white throat tapering to the belly; black flanks with white patches; slender, sleek body. In flight: long, tapering wings angle backward; slightly forked tail.
Size: L 6-7 in. (15-18 cm).
Range: locally uncommon summer breeder in the U.S. Rockies; very rare in the Canadian Rockies.
Habitat: forages in open habitat and breeds on cliffs and large, rocky outcroppings in the foothills.
Nesting: colonial; in a crack or crevice on a cliff face; shallow saucer of twigs and conifer needles is glued together with saliva; pair incubates 4-5 eggs for 18-19 days.
Feeding: on the wing; feeds almost entirely on flying insects.
Voice: shrill, descending laugh: skee-e-e-e.
Similar Species: Vaux's Swif and Black Swift: lack the white and dark underparts. Bank Swallow and Violet-green Swallow: lack the dark flanks with white patches and the wing 'pits.'