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Temporal range: Eocene to present
Apus apus 01.jpg
Common swift, Apus apus
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Apodiformes
Family: Apodidae
Hartert, 1897
A Swift in Trewoon, Cornwall, UK. Swift in Trewoon, Cornwall, UK.jpg
A Swift in Trewoon, Cornwall, UK.

The swifts are a family, Apodidae, of highly aerial birds. They are superficially similar to swallows, but are not closely related to any passerine species. Swifts are placed in the order Apodiformes with hummingbirds. The treeswifts are closely related to the true swifts, but form a separate family, the Hemiprocnidae.


Resemblances between swifts and swallows are due to convergent evolution, reflecting similar life styles based on catching insects in flight. [1]

The family name, Apodidae, is derived from the Greek ἄπους (ápous), meaning "footless", a reference to the small, weak legs of these most aerial of birds. [2] [3] The tradition of depicting swifts without feet continued into the Middle Ages, as seen in the heraldic martlet.


Scaniacypselus fossil Dans l'ombre des dinosaures - Scaniacypselus - 02.jpg
Scaniacypselus fossil

Taxonomists have long classified swifts and treeswifts as relatives of the hummingbirds, a judgment corroborated by the discovery of the Jungornithidae (apparently swift-like hummingbird-relatives) and of primitive hummingbirds such as Eurotrochilus . Traditional taxonomies place the hummingbird family (Trochilidae) in the same order as the swifts and treeswifts (and no other birds); the Sibley-Ahlquist taxonomy treated this group as a superorder in which the swift order was called Trochiliformes.

The taxonomy of the swifts is complicated, with genus and species boundaries widely disputed, especially amongst the swiftlets. Analysis of behavior and vocalizations is complicated by common parallel evolution, while analyses of different morphological traits and of various DNA sequences have yielded equivocal and partly contradictory results. [4]

The Apodiformes diversified during the Eocene, at the end of which the extant families were present; fossil genera are known from all over temperate Europe, between today's Denmark and France, such as the primitive swift-like Scaniacypselus [5] (Early – Middle Eocene) and the more modern Procypseloides (Late Eocene/Early Oligocene – Early Miocene). A prehistoric genus sometimes assigned to the swifts, Primapus (Early Eocene of England), might also be a more distant ancestor.


There are around 100 species of swifts, normally grouped into two subfamilies and four tribes. [6]


  • Tribe Cypseloidini


  • Tribe Collocaliini swiftlets
  • Tribe Chaeturini – needletails
  • Tribe Apodini – typical swifts


Swifts are among the fastest of birds, and larger species like the white-throated needletail have been reported travelling at up to 169 km/h (105 mph) [7] in level flight. Even the common swift can cruise at a maximum speed of 31 metres per second (112 km/h; 70 mph). In a single year the common swift can cover at least 200,000 km. [8] and in a lifetime, about two million kilometers; enough to fly to the Moon five times over. [9]

The wingtip bones of swiftlets are of proportionately greater length than those of most other birds. Changing the angle between the bones of the wingtips and forelimbs allows swifts to alter the shape and area of their wings to increase their efficiency and maneuverability at various speeds. [10] They share with their relatives the hummingbirds a unique ability to rotate their wings from the base, allowing the wing to remain rigid and fully extended and derive power on both the upstroke and downstroke. [11] The downstroke produces both lift and thrust, while the upstroke produces a negative thrust (drag) that is 60% of the thrust generated during the downstrokes, but simultaneously it contributes lift that is also 60% of what is produced during the downstroke. This flight arrangement might benefit the bird's control and maneuverability in the air. [12]

The swiftlets or cave swiftlets have developed a form of echolocation for navigating through dark cave systems where they roost. [13] One species, the Three-toed swiftlet, has recently been found to use this navigation at night outside its cave roost too.

Distribution and habitat

Swifts occur on all the continents except Antarctica, but not in the far north, in large deserts, or on many oceanic islands. [14] The swifts of temperate regions are strongly migratory and winter in the tropics. Some species can survive short periods of cold weather by entering torpor, a state similar to hibernation. [13]

Many have a characteristic shape, with a short forked tail and very long swept-back wings that resemble a crescent or a boomerang. The flight of some species is characterised by a distinctive "flicking" action quite different from swallows. Swifts range in size from the pygmy swiftlet (Collocalia troglodytes), which weighs 5.4 g and measures 9 cm (3.5 in) long, to the purple needletail (Hirundapus celebensis), which weighs 184 g (6.5 oz) and measures 25 cm (9.8 in) long. [13]



Nesting mossy-nest swiftlets Mossy-nest Swiftlets (Aerodramus salangana natunae) on nest (15593076875).jpg
Nesting mossy-nest swiftlets

The nest of many species is glued to a vertical surface with saliva, and the genus Aerodramus use only that substance, which is the basis for bird's nest soup. Other swifts select holes and small cavities in walls. [15] The eggs hatch after 19 to 23 days, and the young leave the nest after a further six to eight weeks. Both parents assist in raising the young. [13]

Swifts as a family have smaller egg clutches and much longer and more variable incubation and fledging times than passerines with similarly sized eggs, resembling tubenoses in these developmental factors. Young birds reach a maximum weight heavier than their parents; they can cope with not being fed for long periods of time, and delay their feather growth when undernourished. Swifts and seabirds have generally secure nest sites, but their food sources are unreliable, whereas passerines are vulnerable in the nest but food is usually plentiful. [16] [17]


All swifts eat insects, such as dragonflies, flies, ants, aphids, wasps and bees as well as aerial spiders. Prey is typically caught in flight using the beak. Some species, like the chimney swift, hunt in mixed species flocks with other aerial insectivores such as members of Hirundinidae (swallows) [18] .


No swift species has become extinct since 1600, [19] but BirdLife International has assessed the Guam swiftlet as endangered and lists the Atiu, dark-rumped, Schouteden's, Seychelles, and Tahiti swiftlets as vulnerable; twelve other species are near threatened or lack sufficient data for classification. [20]

Exploitation by humans

The hardened saliva nests of the edible-nest swiftlet and the black-nest swiftlet have been used in Chinese cooking for over 400 years, most often as bird's nest soup. [21] Over-harvesting of this expensive delicacy has led to a decline in the numbers of these swiftlets, [22] [23] especially as the nests are also thought to have health benefits and aphrodisiac properties. Most nests are built during the breeding season by the male swiftlet over a period of 35 days. They take the shape of a shallow cup stuck to the cave wall. The nests are composed of interwoven strands of salivary cement and contain high levels of calcium, iron, potassium, and magnesium. [23]

See also

Related Research Articles

Common swift Species of bird

The common swift is a medium-sized bird, superficially similar to the barn swallow or house martin but somewhat larger, though not stemming from those passerine species, being in the order Apodiformes. The resemblances between the groups are due to convergent evolution, reflecting similar contextual development. The swifts' nearest relatives are the New World hummingbirds and the Southeast Asian treeswifts.

Apodiformes Order of birds

Traditionally, the bird order Apodiformes contained three living families: the swifts (Apodidae), the treeswifts (Hemiprocnidae), and the hummingbirds (Trochilidae). In the Sibley-Ahlquist taxonomy, this order is raised to a superorder Apodimorphae in which hummingbirds are separated as a new order, Trochiliformes. With nearly 450 species identified to date, they are the most diverse order of birds after the passerines.

Treeswift Family of birds

Treeswifts or crested swifts are a family, Hemiprocnidae, of aerial near passerine birds, closely related to the true swifts. The family contains a single genus, Hemiprocne, with four species. They are distributed from India and South East Asia through Indonesia to New Guinea and the Solomon Islands.

Alpine swift Species of bird

The Alpine swift formerly Apus melba, is a species of swift. The genus name is from the Ancient Greek takhus, "fast", and marptis, "seizer". The specific name melba comes from ‘melano-alba’ or ‘mel-alba’; Eigenhuis & Swaab (1992) posited that ‘melba’ might be a short form for ‘melano-alba’ or ‘mel-alba’. Linnaeus certainly referred to these two colors in his diagnosis.

Little swift Species of bird

The little swift, is a small species of swift found in Africa and southwestern Asia, and are vagrants and local breeders in southern Europe. They are found both in urban areas and at rocky cliffs where they build nests in a way typical of all members of the order Apodiformes. The genus name Apus is Latin for a swift, thought by the ancients to be a type of swallow without feet. The Latin specific affinis means similar to or related to, but in this case the species that the little swift supposedly resembles is not clear from the description. A population formerly considered to be an eastern subspecies of little swift is now separated as a distinct species, the house swift.

Pacific swift Species of bird which breeds in eastern Asia

The Pacific swift is a species of bird that is part of the Swift family. It breeds in eastern Asia. It is strongly migratory, spending the northern hemisphere's winter in Southeast Asia and Australia. The general shape and blackish plumage recall its relative, the common swift, from which it is distinguished by a white rump band and heavily marked underparts. The sexes are identical in appearance, although young birds can be identified by pale fringes to the wing feathers that are absent in adults. This swift's main call is a screech typical of its family. It is one of a group of closely related Asian swifts formerly regarded as one species.

Swiftlet Tribe of birds in the swift family

Swiftlets are birds contained within the four genera Aerodramus, Hydrochous, Schoutedenapus and Collocalia. They form the Collocaliini tribe within the swift family Apodidae. The group contains around thirty species mostly confined to southern Asia, south Pacific islands, and northeastern Australia, all within the tropical and subtropical regions. They are in many respects typical members of the Apodidae, having narrow wings for fast flight, with a wide gape and small reduced beak surrounded by bristles for catching insects in flight. What distinguishes many but not all species from other swifts and indeed almost all other birds is their ability to use a simple but effective form of echolocation to navigate in total darkness through the chasms and shafts of the caves where they roost at night and breed. The nests of some species are built entirely from threads of their saliva, and are collected for the famous Chinese delicacy bird's nest soup.

<i>Aerodramus</i> Genus of birds

Aerodramus is a genus of small, dark, cave-nesting birds in the Collocaliini tribe of the swift family. Its members are confined to tropical and subtropical regions in southern Asia, Oceania and northeastern Australia. Many of its members were formerly classified in Collocalia, but were first placed in a separate genus by American ornithologist Harry Church Oberholser in 1906.

White-throated swift Species of bird

The white-throated swift is a swift of the family Apodidae native to western North America, south to cordilleran western Honduras. Its coastal range extends as far north as Northern California, while inland it has migratory populations found throughout the Great Basin and Rocky Mountain regions, ranging as far north as southern British Columbia. White-throated swifts are found in open areas near cliffs, rock faces, or man-made structures, where they roost. Swifts are social birds, and groups are often seen roosting and foraging for flying insects together.

Seychelles swiftlet Species of bird

The Seychelles swiftlet is a small bird of the swift family. It is found only in the Seychelles Islands in the Indian Ocean.

Edible-nest swiftlet Species of bird

The edible-nest swiftlet, also known as the white-nest swiftlet, is a small bird of the swift family which is found in South-East Asia. Its nest is made of solidified saliva and is used to make bird's nest soup.

Germains swiftlet Species of bird

Germain's swiftlet is a species of swift.

The mountain swiftlet is a species of swift in the family Apodidae. It is endemic to the island of New Guinea and the nearby islands of Karkar, Yapen and Goodenough. It was once placed in the genus Collocalia but has been moved, with many others, to Aerodramus. The species is divided into three subspecies, with the nominate, A. h. hirundinacea ranging over most of New Guinea, the subspecies A. h. excelsus occurring over 1600 m in the Snow Mountains and Cartenz peaks of Irian Jaya and A. h. baru being restricted to Yapen Island. It occurs in alpine areas from 500 m to the treeline. Its natural habitat is tropical moist montane forests and other mountainous habitats in New Guinea. It also occurs in lower numbers in the lowlands near hills.

Cave swiftlet Species of bird

The cave swiftlet is a species of swift in the family Apodidae. It is found on the Indonesia islands of Sumatra, Java and Bali. It is a woodland species and nests in caves. The Bornean swiftlet was considered a subspecies, but is now usually considered distinct.

Australian swiftlet Species of bird

The Australian swiftlet is a small bird belonging to the genus Aerodramus in the swift family, Apodidae. It is endemic to Queensland in north-eastern Australia. It was formerly included in the white-rumped swiftlet but is now commonly treated as a separate species. It has two subspecies which are occasionally regarded as two separate species: A. t. terraereginae and A. t. chillagoensis.


Apodimorphae is a clade of strisorean birds that include the extant families Trochilidae (hummingbirds), Hemiprocnidae (treeswifts), Apodidae (swifts), and Aegothelidae (owlet-nightjars), as well as many fossil families. This grouping of birds has been supported in a variety of recent studies. There are two higher classification schemes that have been proposed for the apodimorph families. One is all strisorean birds are classified in the order Caprimulgiformes, while the other is the strisorean birds are split into several distinct orders. In this case Apodimorphae is a subclade of Strisores that includes the orders Aegotheliformes and the Apodiformes. A similar name for the group Daedalornithes has been used for the owlet-night-apodiform clade, there is a difference between the two names with Apodimorphae defined as the total-group and Daedalornithes defined as the crowned group.

The Christmas Island swiftlet, also known as the Christmas glossy swiftlet or the Christmas cave swiftlet, is a small bird in the swift family Apodidae. It is endemic to Christmas Island, an Australian territory in the eastern Indian Ocean. It was formerly commonly treated as a subspecies of the glossy swiftlet.

Apodinae Subfamily of birds

The Apodinae are a subfamily of swifts and contain the following species:

Ridgetop swiftlet Species of bird

The ridgetop swiftlet is a small bird in the swift family Apodidae. It is endemic to the Philippines.


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