The Amazonian Swift is rather recently but already almost universally recognized species; it was formerly treated as a subspecies of the more northerly distributed Chapman’s Swift (Chaetura chapmani), from which this species differs in its even less contrasting plumage and in biometrics (e.g. longer wings and tail). These two species probably largely replace one another north and south of the Amazon, but given that the Amazonian Swift apparently performs migrations, and that major rivers present none of the barriers that they do to many species, the possibility of, at least occasional, overlap cannot be eliminated. The Amazonian Swift is suspected to be a relatively low-density species, although its range is probably even wider than marked on the map, and may even reach eastern Amazonian Brazil. It is postulated to breed in the austral summer, but the species’ nesting areas apparently remain undiscovered.