White-tipped Swift

The white-tipped swift is 12 to 13 cm (4.7 to 5.1 in) long and weighs 17 to 33 g (0.60 to 1.2 oz). It has slim pointed wings and a long slightly notched tail. Adult males of the nominate subspecies are blackish brown on the crown and around the eye; most of the rest of the face is gray brown. Their upperparts are the same blackish brown as the crown. Their tail is black-brown with wide white tips to the feathers. Their wings are blackish brown with white edges on some feathers. Their throat, sides of the neck, and the upper breast are white. The rest of their underparts are a slightly lighter blackish brown than the upperparts, with white patches around the legs. Adult females are browner than males with sometimes a paler lower back and rump. The white of the throat is duller and the white tips of the tail reduced or absent. Juveniles are similar to adults with the addition of pale fringes to body feathers. Subspecies A. m. tatei is similar to the nominate, but their upperparts are a very glossy blue black.

The nominate subspecies of white-tipped swift is found in the Venezuelan Coastal Range and separately in the Andes from extreme western Venezuela south through Colombia, Ecuador, Peru, and Bolivia into northern Argentina. A. m. tatei is found in the tepui region along the border between southern Venezuela and northwestern Brazil. Sight records in Guyana and documented records in Suriname and French Guiana are probably of this subspecies. The species is mostly seen over montane evergreen forest but also occurs in drier intermontane valleys in Ecuador and northern Peru. Its elevational limits vary geographically. It occurs between about 500 and 1,900 m (1,600 and 6,200 ft) in the tepui region, 800 and 2,600 m (2,600 and 8,500 ft) in coastal and Andean Venezuela, in Ecuador from 600 to 3,200 m (2,000 to 10,500 ft) but mostly between 1,500 and 2,000 m (4,900 and 6,600 ft), usually between 1,200 and 2,400 m (3,900 and 7,900 ft) in Peru, and usually between 500 and 2,600 m (1,600 and 8,500 ft) in Bolivia.

Like all swifts, the white-tipped is an aerial insectivore. Details of its diet are lacking but it is known to feed on flying ants, beetles, and moths. It often feeds with other species of swift, but also in flocks of only its kind; flocks may number up to 50 birds. It tends to forage low over forest but in canyons it stays at ridge-top altitude.