The Common Swift (Apus apus) is a small bird, superficially similar to the swallow or house martin. It is, however, completely unrelated to those Passerine species, since swifts are in the order Apodiformes. The resemblances between the groups are due to convergent evolution reflecting similar life styles.
The scientific name comes from the Greek απους, apous, meaning "without feet". These birds have very short legs which they use only for clinging to vertical surfaces (hence the German name Mauersegler, literally meaning "wall-glider"). They never settle voluntarily on the ground. The heraldic bird known as the "martlet", which is represented without feet and may have been based on the swift, was used for the arms of younger sons, perhaps because it symbolized their landless wandering.
Swifts will occasionally live in forests, but they have adapted more commonly to human sites and will build their nests under window sills, in the corner rafters of wooden buildings, in chimneys, and in smokestacks. A swift will return to the same nesting site year after year, rebuilding its nest when necessary.
Young swifts in the nest can drop their body temperature and become torpid if bad weather prevents their parents from catching insects nearby.
Swifts spend most of their lives in the air, living on the insects they catch in their beaks. They drink and even sleep on the wing. No other bird spends as much of its life in flight.
Common Swifts are entirely black except for a small white or pale grey patch on their chins which is not visible from a distance. They have a short forked tail and very long swept-back wings that resemble a crescent or a boomerang.
The call is a loud scream, giving rise to the old name of Devil Bird.
- Chimney Swift
- Alpine Swift
- Little Swift
- Needletail Swift
In the Sibley-Ahlquist taxonomy, the old order Apodiformes is split. Swifts remain in that order, but hummingbirds are put into a new order, Trochiliformes.
See also: Food therapy ("Bird nest" section)