A large, black swift with a complete white collar, the White-collared Swift can be found in a wide range of habitats at a wide range of altitudes. Most commonly found in montane or submontane evergreen forests, the White-collared Swift spends most of the day on the wing, in flocks of as many as 200 individuals, hunting for flying insects. These flocks may contain members of several species of swifts, although White-collared Swifts also form large single-species flocks. This species has a clutch size of two eggs and can nest either colonially or individually at the mouth of caves, behind waterfalls, and on other dark, vertical surfaces. The White-collared Swift displays a variety of migratory strategies throughout its range, with some populations being altitudinal migrants and other populations being nonmigratory.