About Chaetura cinereiventris P.L.Sclater, 1862
The grey-rumped swift (Chaetura cinereiventris P.L.Sclater, 1862) is approximately 10.5 cm (4.1 in) long and weighs around 17 g (0.60 oz). It has a protruding head, a short square tail, wings that bulge in the middle and curve slightly to a hooked end. Males and females have identical plumage. Adults of the nominate subspecies have mostly glossy black upperparts, with a wide gray rump and uppertail coverts. Their underparts are lighter gray than the rump, and darker on the undertail coverts. Juveniles match adult plumage almost exactly, except that most of their wing feathers have pale fringes. Subspecies C. c. phaeopygos differs from the nominate subspecies only by having pale undertail coverts. C. c. lawrencei has slightly darker underparts than the nominate, with black undertail coverts that create a contrast with its belly. C. c. schistacea has darker upperparts than the nominate, with a steely blue gloss, and also deep gray underparts. C. c. guianensis is nearly identical to the nominate subspecies. C. c. occidentalis and C. c. sclateri have the darkest rumps out of all recognized subspecies, along with blackish gray bellies. Each subspecies of the grey-rumped swift has a distinct distribution. C. c. phaeopygos is found in northeastern Honduras, and from eastern Nicaragua through Costa Rica into northwestern Panama. C. c. lawrencei occurs in northern Venezuela, Trinidad, Tobago, and Grenada. C. c. schistacea inhabits the Andes from Mérida state in western Venezuela to Boyacá Department in eastern Colombia. C. c. guianensis lives in eastern Venezuela and western Guyana. C. c. occidentalis ranges from western Colombia through western Ecuador into Tumbes department in extreme northwestern Peru. C. c. sclateri is found in scattered areas across southern Venezuela, southern Colombia, the upper Amazon basin of northwestern Brazil, eastern Peru, and northwestern Bolivia. The nominate subspecies C. c. cinereiventris occurs in southeastern Brazil south of Bahia, through eastern Paraguay, into Misiones Province of Argentina. The grey-rumped swift lives in a diverse set of landscapes: lowland tropical evergreen forest, montane evergreen forest, seasonally flooded tropical evergreen forest, and secondary forest. It can be found from sea level up to 1,800 m (5,900 ft) in elevation.
