Treeswifts or crested swifts are a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

, the Hemiprocnidae, of aerial near passerine

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s, closely related to the true swifts. The family contains a single

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

, ''Hemiprocne'', with four species. They are distributed from

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

and

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainland ...

through

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Gui ...

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torres ...

and the

Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capit ...

. Treeswifts are small to medium-sized swifts, ranging in length from 15 to 30 cm. They have long wings, with most of the length coming from the length of the

primaries Primary elections, or direct primary are a voting process by which voters can indicate their preference for their party's candidate, or a candidate in general, in an upcoming general election, local election, or by-election. Depending on the c ...

; their arms are actually quite short. They visibly differ from the other swifts in matters of

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

, which is softer, and they have crests or other facial ornaments, and long, forked tails. Anatomically they are separated from the true swifts by skeletal details in the cranium and palate, the anatomy of the tarsus, and a nonreversible hind toe that is used for perching on branches (an activity in which true swifts are unable to engage). The males have

iridescent Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfl ...

mantle plumage. They also have diastataxic wings, that is they lack a fifth secondary feather unlike swifts in the Apodini, which are eutaxic. Moustached Treeswift (Hemiprocne mystacea)

Moustached Treeswift (Hemiprocne mystacea)

The treeswifts exhibit a wide range of habitat preferences. One species, the whiskered treeswift, is a species belonging to

primary forest An old-growth forestalso termed primary forest, virgin forest, late seral forest, primeval forest, or first-growth forestis a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological feature ...

. Highly manoeuvrable, it feeds close to vegetation beneath the canopy, and only rarely ventures into secondary forests or plantations, but never over open ground. Other species are less restricted; the crested treeswift makes use of a range of habitats including humid forests and deciduous woodland, and the grey-rumped treeswift occupies almost every habitat type available from the

mangrove A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in severa ...

forests to hill forests. All species feed on insects, although exact details of what prey are taken has not been studied in detail. Nest-building responsibilities are shared by the male and female. They lay one egg in the nest, which is glued to an open tree branch. Egg colour varies from white to grey. Little information is available about incubation times, but they are thought to be longer for the larger species. Chicks hatch with a covering of grey down and are fed a bolus of regurgitated food by the parents.

Species

* Crested treeswift, ''H. coronata'' * Grey-rumped treeswift, ''H. longipennis'' * Whiskered treeswift, ''H. comata'' * Moustached treeswift, ''H. mystacea''

Species

References

Further reading