Pallid Swift
Encyclopedia
The Pallid Swift is a small bird
, superficially similar to a Barn Swallow
or House Martin
. It is, however, completely unrelated to those passerine
species, since the swift
s are in the order Apodiformes. The resemblances between the groups are due to convergent evolution
reflecting similar life styles.
Swifts have very short legs which they use only for clinging to vertical surfaces. The scientific name comes from the Ancient Greek
απους, apous, meaning "without feet". They never settle voluntarily on the ground. Swifts spend most of their lives in the air, living on the insects they catch in their beaks. They drink on the wing.
in 1870.
, and separation is only possible with good views. Like its relative, it has a short forked tail and very long swept-back wings that resemble a crescent or a boomerang
.
It is entirely dark except for a large white throat patch which is frequently visible from a distance. It is chunkier and browner than Common Swift, and the slightly paler flight feathers, underparts and rump give more contrast than that species. It also has a scalier looking belly and subtly different flight action. The call is a loud dry scream similar to that of its relative, though possibly more disyllabic.
and Madeira
, laying two eggs. Like swallows, they are migratory
, winter in southern Africa
or southeast Asia
.
They are rare north of their breeding areas, although they are likely to be under-recorded due to identification problems. Because of its more southerly range, Pallid Swift arrives earlier and leaves later than the closely related Common Swift, so particularly early or late swifts north of the normal range should be carefully observed.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
, superficially similar to a Barn Swallow
Barn Swallow
The Barn Swallow is the most widespread species of swallow in the world. It is a distinctive passerine bird with blue upperparts, a long, deeply forked tail and curved, pointed wings. It is found in Europe, Asia, Africa and the Americas...
or House Martin
House Martin
The Common House Martin , sometimes called the Northern House Martin or, particularly in Europe, just House Martin, is a migratory passerine bird of the swallow family which breeds in Europe, north Africa and temperate Asia; and winters in sub-Saharan Africa and tropical Asia...
. It is, however, completely unrelated to those passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
species, since the swift
Swift
The swifts are a family, Apodidae, of highly aerial birds. They are superficially similar to swallows, but are actually not closely related to passerine species at all; swifts are in the separate order Apodiformes, which they share with hummingbirds...
s are in the order Apodiformes. The resemblances between the groups are due to convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
reflecting similar life styles.
Swifts have very short legs which they use only for clinging to vertical surfaces. The scientific name comes from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
απους, apous, meaning "without feet". They never settle voluntarily on the ground. Swifts spend most of their lives in the air, living on the insects they catch in their beaks. They drink on the wing.
Taxonomy
The Pallid Swift was first described by English naturalist George Ernest ShelleyGeorge Ernest Shelley
Captain George Ernest Shelley was an English geologist and ornithologist. He was a nephew of the poet Percy Bysshe Shelley....
in 1870.
Description
This 16-17 cm (6.4-6.8 in) long species is very similar to the Common SwiftCommon Swift
The Common Swift is a small bird, superficially similar to the Barn Swallow or House Martin. It is, however, completely unrelated to those passerine species, since swifts are in the separate order Apodiformes...
, and separation is only possible with good views. Like its relative, it has a short forked tail and very long swept-back wings that resemble a crescent or a boomerang
Boomerang
A boomerang is a flying tool with a curved shape used as a weapon or for sport.-Description:A boomerang is usually thought of as a wooden device, although historically boomerang-like devices have also been made from bones. Modern boomerangs used for sport are often made from carbon fibre-reinforced...
.
It is entirely dark except for a large white throat patch which is frequently visible from a distance. It is chunkier and browner than Common Swift, and the slightly paler flight feathers, underparts and rump give more contrast than that species. It also has a scalier looking belly and subtly different flight action. The call is a loud dry scream similar to that of its relative, though possibly more disyllabic.
Distribution and habitat
Pallid Swifts breed on cliffs and eaves around the Mediterranean and on the Canary IslandsCanary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
and Madeira
Madeira
Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...
, laying two eggs. Like swallows, they are migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, winter in southern Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
or southeast Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
.
They are rare north of their breeding areas, although they are likely to be under-recorded due to identification problems. Because of its more southerly range, Pallid Swift arrives earlier and leaves later than the closely related Common Swift, so particularly early or late swifts north of the normal range should be carefully observed.