Swifts (Apodidae) are a group of birds that include American swifts, swiftlets, spinetails, and typical swifts. There are about 83 species of swifts alive today. Swifts inhabit all continents except Antarctica. They inhabit a variety of terrestrial habitats including grasslands, scrublands, steppe, urban areas, and forests.Swifts are superb arealists that have sickle-shaped wings well-suited for fast, maneuverable flight. Swifts have very small, delicate feet and are not able to perch.
However, swifts are able to grasp vertical surfaces since their rigid tail feathers provide additional support. Swifts build their nests in caves, the hollows of trees or other crevices. They use their saliva as a type of adherent that enables them to attach the nest to the underlying surface and to glue nesting material together. In China, the nests of the species Aerodramus fuciphagus, known commonly as edible-nest swiflets, are considered a culinary delicacy and are used to make bird’s nest soup.
Swifts feed on insects they catch as they fly. This behavior of feeding while in flight is known as hawking. Swifts require foraging habitat where flying insects are dense. Swifts also obtain their water while flying, but skimming the surface of the water with an open beak as they fly over it. Swifts are social birds that feed and roost in large, mixed flocks. Many types of swifts breed in large colonies although some species are solitary.
Swifts are among the fastest fliers in the animal kingdom. Among the fastest swifts are the white-throated needletail that has been observed flying at speeds of more than 100 miles per hour. Common swifts have been measured flying at speeds of as much as 70 miles per hour. Swifts have a number of modifications to the anatomy of their wings that enable this fast, maneuverable flight. Their humerous bones are short and the wingtip bones are elongated, changing the angle of the wing arc and in turn the manner of flight.
Swifts are prey for a variety of predators including hobbies, falcons, hawks, owls, and crows. They are also prey to snakes, and (surprisingly) cave crickets.
Swifts have dull plumage and are usually black, grey or brown. Some swifts have a white throat or light patch on their rump. A few species also have chestnut or reddish markings on their throat. Males and females resemble one another.