Plain Swift
Encyclopedia
The Plain Swift is a medium-sized swift
. Although this bird
is superficially similar to a Barn Swallow
or House Martin
, it is not related to those passerine
species. The resemblances between the groups are due to convergent evolution
reflecting similar life styles.
Swifts have very short legs that they use only for clinging to vertical surfaces. They never settle voluntarily on the ground, and spend most of their lives in the air, feeding on insect
s that they catch in their beaks. They drink on the wing.
Plain Swifts breed in colonies on cliffs, bridges and buildings on the Canary Islands
and Madeira
, laying two eggs in a saucer-shaped nest made of floerheads glued with saliva. They are partially migratory
, with some birds leaving to winter in northwest Africa
.
This 14-15 cm long species is very similar to the closely related Common
and Pallid Swift
s, which also occur in the archipelagos, and separation is only possible with good views. Like its relatives, 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 an indistinct pale throat patch. It is slimmer and more rakish than the Pallid Swift, and is darker than that species and lacks the obvious white throat.
Distinguishing the Plain Swift from the similarly plumaged Common Swift is much more difficult, although juvenile Common can be easily eliminated due to its white throat. The Plain is slimmer and appears longer winged than the Common, and has scaly underparts, difficult to see except with excellent views. The call is a loud dry scream similar to that of the Common Swift, though possibly higher pitched.
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...
. Although this bird
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...
is 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 not related 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. 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 that they use only for clinging to vertical surfaces. They never settle voluntarily on the ground, and spend most of their lives in the air, feeding on insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s that they catch in their beaks. They drink on the wing.
Plain Swifts breed in colonies on cliffs, bridges and buildings on the Canary Islands
Canary 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 in a saucer-shaped nest made of floerheads glued with saliva. They are partially 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...
, with some birds leaving to winter in northwest 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...
.
This 14-15 cm long species is very similar to the closely related Common
Common 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 Pallid Swift
Pallid Swift
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 swifts are in the order Apodiformes...
s, which also occur in the archipelagos, and separation is only possible with good views. Like its relatives, 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 an indistinct pale throat patch. It is slimmer and more rakish than the Pallid Swift, and is darker than that species and lacks the obvious white throat.
Distinguishing the Plain Swift from the similarly plumaged Common Swift is much more difficult, although juvenile Common can be easily eliminated due to its white throat. The Plain is slimmer and appears longer winged than the Common, and has scaly underparts, difficult to see except with excellent views. The call is a loud dry scream similar to that of the Common Swift, though possibly higher pitched.