Very small swift with stiff, quick wingbeats. Dark grayish-brown overall with paler throat and brownish rump. Often in small flocks. Listen for its high-pitched chips and trills. Occurs in eastern Venezuela and presumably western Guyana. Compared with Vaux’s Swift in western Venezuela, Ashy-tailed is darker below with a more well-defined pale throat, and has paler upperparts, but identification is often presumed based on range. Vocal differences are not well known.