The American Black Swift is a large swift that breeds in mountains of western North America. It moves south for winter, but its winter range is poorly known.
It is dark overall, with long, sickle-shaped wings.
It catches insects in flight, including winged ants, and nests on inaccessible ledges, often behind waterfalls or on cliffs.
It builds a shallow cup of moss and mud and may reuse the nest in later breeding seasons.
It lays one white egg, with an incubation period of 23–30 days; the chick hatches naked with closed eyes.
It forages high on clear days and lower on cloudy days, and drinks by dipping its bill into a lake or pond during low flight.
Juveniles are blackish with white edging on the body and flight feathers.
An extinction-risk assessment has not been added yet.