Editing Swift (bird)

{{Short description|Family of birds}}
{{Automatic taxobox
|fossil_range = {{fossil range|Eocene|Present|[[Eocene]] to present}}
|image = Apus apus 01.jpg
|image_caption = [[Common swift]], ''Apus apus''
|taxon = Apodidae
|authority = [[Ernst Hartert|Hartert]], 1897
|subdivision_ranks = Subfamilies
|subdivision = 
*[[Cypseloidinae]]
*[[Apodinae]]
}}

The '''Apodidae''', or '''swifts''', form a family of highly aerial [[bird]]s. They are superficially similar to [[swallow]]s, but are not closely related to any [[passerine]] species. Swifts are placed in the order [[Apodiformes]] along with [[hummingbird]]s. The [[treeswift]]s 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 [[insect]]s in flight.<ref>{{cite journal |last1=Hasegawa |first1=Masaru |last2=Arai |first2=Emi |title=Convergent evolution of the tradeoff between egg size and tail fork depth in swallows and swifts |journal=Journal of Avian Biology |date=12 June 2018 |volume=49 |issue=8 |page=1 |doi=10.1111/jav.01684 |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/jav.01684 |access-date=12 February 2021|url-access=subscription }}</ref>

The family name, Apodidae, is derived from the [[Greek language|Greek]] ἄπους (''ápous''), meaning "footless", a reference to the small, weak legs of these most aerial of birds.<ref name= job59>Jobling (2010) pp. 50–51.</ref><ref name= Kaufman>Kaufman (2001) p. 329.</ref> The tradition of depicting swifts without feet continued into the Middle Ages, as seen in the heraldic [[martlet]].

==Taxonomy==
[[File:Dans l'ombre des dinosaures - Scaniacypselus - 02.jpg|upright|thumb|right|''Scaniacypselus'' fossil]]
Taxonomists have long classified swifts and treeswifts as relatives of the [[hummingbird]]s, 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 [[swiftlet]]s. Analysis of behavior and vocalizations is complicated by common [[parallel evolution]], while analyses of different [[Morphology (biology)|morphological traits]] and of various [[DNA sequences]] have yielded equivocal and partly contradictory results.<ref>{{cite journal | last1 = Thomassen | first1 = Henri A. | last2 = Tex | first2 = Robert-Jan | last3 = de Bakker | first3 = Merijn A.G. | last4 = Povel | first4 = G. David E. | year = 2005 | title = Phylogenetic relationships amongst swifts and swiftlets: A multi locus approach | journal = Molecular Phylogenetics and Evolution | volume = 37 | issue = 1| pages = 264–277 | doi = 10.1016/j.ympev.2005.05.010 | pmid=16006151}}</ref>

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]]''<ref name= mayr>{{cite journal |last= Mayr |first= Gerald |year= 2003 |title= A new Eocene swift-like bird with a peculiar feathering |journal= Ibis |volume= 145 |pages= 382–391 |url= http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/ibissegler.pdf |doi= 10.1046/j.1474-919x.2003.00168.x |issue= 3 |access-date= 2013-10-27 |archive-url= https://web.archive.org/web/20160303225052/http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/ibissegler.pdf |archive-date= 2016-03-03 |url-status= dead }}</ref> (Early–Middle Eocene) and the more modern ''[[Procypseloides]]'' (Late Eocene/Early [[Oligocene]] – Early [[Miocene]])<!-- Geobios36:719 -->. A prehistoric genus sometimes assigned to the swifts, ''[[Primapus]]'' (Early Eocene of England), might also be a more distant ancestor.

===Species===
{{Main|List of swift species}}
There are around 100 species of swifts, normally grouped into two subfamilies and four tribes.<ref name=chantler19>Chantler & Driessens (2000) pp. 19–20</ref>

'''[[Cypseloidinae]]'''
:*Tribe Cypseloidini
'''[[Apodinae]]'''
:*Tribe Collocaliini '''– [[swiftlets]]''' 
:*Tribe Chaeturini ''' – needletails'''
:*Tribe Apodini ''' – typical swifts'''

==Description==
Swifts are among the fastest of birds in level flight, and larger species like the [[white-throated needletail]] have been reported travelling at up to {{convert|169|km/h|mph|abbr=on}}.<ref name="BBCnews">{{cite news| url=http://news.bbc.co.uk/earth/hi/earth_news/newsid_8539000/8539383.stm| work=BBC News | first=Jody | last=Bourton | title=Supercharged swifts fly fastest | date=2 March 2010}}</ref> Even the [[common swift]] can cruise at a maximum speed of 31 [[metre per second|metres per second]] ({{convert|112|km/h|mph|abbr=on|disp=x|; }}). In a single year the common swift can cover at least 200,000&nbsp;km,<ref>[[Ross Piper|Piper, Ross]] (2007), ''Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals'', [[Greenwood Press (publisher)|Greenwood Press]],</ref> and in a lifetime, about two million kilometers.<ref>{{Cite web|url=https://www.lrb.co.uk/the-paper/v41/n16/katherine-rundell/consider-the-swift|title=Consider the Swift|last=Rundell|first=Katherine|date=August 15, 2019|website=London Review of Books}}</ref>

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.<ref>[http://www.naturalhistorymag.com/biomechanics/02944/on-swift-wings On Swift Wings | Natural History Magazine]</ref> They share with their relatives the [[hummingbird]]s a special 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.<ref>[https://books.google.com/books?id=40mFwoALUFUC&dq=%22power+on+both+upstroke+and+down-+stroke.%22&pg=PA382 Birds of Venezuela – Steven L. Hilty]</ref> 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.<ref>[http://jeb.biologists.org/content/211/5/717.full Vortex wake and flight kinematics of a swift in cruising flight in a wind tunnel]</ref>

The [[swiftlet]]s or cave swiftlets have developed a form of [[Animal echolocation|echolocation]] for navigating through dark cave systems where they roost.<ref name=EoB/> 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.<ref name = H&C>{{Cite book | last = Martins | first = Thais | author2 = Mead, Christopher J. | year = 2003 | chapter = Swifts | editor = Perrins, Christopher | editor-link = Chris Perrins | title = The Firefly Encyclopedia of Birds | publisher = Firefly Books | pages = [https://archive.org/details/fireflyencyclope0000unse/page/346 346–350] | isbn = 1-55297-777-3 | chapter-url-access = registration | chapter-url = https://archive.org/details/fireflyencyclope0000unse/page/346 }}</ref> The swifts of temperate regions are strongly [[bird migration|migratory]] and winter in the tropics. Some species can survive short periods of cold weather by entering [[torpor]], a state similar to hibernation.<ref name=EoB>{{Cite book|editor=Forshaw, Joseph|author= Collins, Charles T.|year=1991|title=Encyclopaedia of Animals: Birds|publisher= Merehurst Press|location=London|pages= 134–136|isbn= 1-85391-186-0}}</ref>

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 {{convert|9|cm|in|abbr=on}} long, to the [[purple needletail]] (''Hirundapus celebensis''), which weighs {{convert|184|g|oz|abbr=on}} and measures {{convert|25|cm|in|abbr=on}} long.<ref name=EoB/>

==Behaviour==

===Breeding===
[[File:Mossy-nest Swiftlets (Aerodramus salangana natunae) on nest (15593076875).jpg|thumb|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.<ref name=Corrales2013/>  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.<ref name=EoB/>

Swifts as a family have smaller egg clutches and much longer and more variable incubation and fledging times than [[passerine]]s with similarly sized eggs, resembling [[Procellariiformes|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.<ref name= lacklack>{{cite journal |last= Lack |first= David |author2=Lack, Elizabeth  |year=1951 |title= The breeding biology of the Swift ''Apus apus'' | journal= Ibis | volume= 93 | pages=501–546 |doi=10.1111/j.1474-919X.1951.tb05457.x |issue=4}}</ref><ref name= Boersma>{{cite journal |last= Boersma |first= P Dee |year= 1982|title=Why some birds take so long to hatch | journal= The American Naturalist | volume=120 | pages=733–750 |doi=10.1086/284027|jstor=2461170 |issue=6|s2cid= 83600491 }}</ref>

===Feeding===

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 [[Swallow|Hirundinidae (swallows)]].<ref>{{Cite book|last=Dunne|first=Pete|url=https://www.worldcat.org/oclc/61169710|title=Pete Dunne's essential field guide companion|date=2006|publisher=Houghton Mifflin Co|isbn=978-0-618-23648-0|location=Boston|oclc=61169710}}</ref>

==Status==

No swift species has become extinct since 1600,<ref name=hbwonlinefam>{{cite web |editor1-last=del Hoyo |editor1-first=Josep |editor2-last=Elliott |editor2-first=Andrew |editor3-last=Sargatal |editor3-first=Jordi |editor4-last=Christie |editor4-first=David A. |editor5-last=de Juana |editor5-first=Eduardo |title=Apodidae |work=Handbook of the Birds of the World Alive |url=http://www.hbw.com/family/swifts-apodidae |publisher=Lynx Edicions |access-date=10 September 2013 |url-access=subscription }}</ref> but [[BirdLife International]] has assessed the [[Guam swiftlet]] as [[endangered species|endangered]] and lists the [[Atiu swiftlet|Atiu]], [[dark-rumped swift|dark-rumped]], [[Seychelles swiftlet|Seychelles]], and [[Tahiti swiftlet]]s as [[vulnerable species|vulnerable]]; twelve other species are [[near threatened]] or lack sufficient data for classification.<ref name=birdlifeapodidiae>{{cite web |title=Apodidae |work=Species |url=http://www.birdlife.org/datazone/sowbsearchresults.php?a=ns&SearchTerms=apodidae |publisher=BirdLife International |access-date=27 October 2013 }}</ref>

==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 [[edible bird's nest|bird's nest soup]].<ref name=Hobbs>{{cite journal |last=Hobbs |first=Joseph J |year= 2004|title= Problems in the harvest of edible birds' nests in Sarawak and Sabah, Malaysian Borneo| journal=Biodiversity and Conservation | volume= 13| pages=2209–2226 |doi=10.1023/b:bioc.0000047905.79709.7f|issue=12|s2cid=34483704 }}</ref> Over-harvesting of this expensive delicacy has led to a decline in the numbers of these swiftlets,<ref name=Gausset>{{cite journal |last= Gausset|first=Quentin |year= 2004|title=Chronicle of a Foreseeable Tragedy: Birds' Nests Management in the Niah Caves (Sarawak) | journal= Human Ecology| volume=32 | pages=487–506 |doi=10.1023/b:huec.0000043517.23277.54|issue=4|s2cid=154898420 }}</ref><ref name=MarconeA>{{cite journal |last=Marcone |first= Massimo F|year= 2005|title=Characterization of the edible bird's nest the ''Caviar of the East'' | journal=Food Research International | volume=38 | pages=1125–1134 |doi=10.1016/j.foodres.2005.02.008|issue=10}}</ref> 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.<ref name=MarconeA/>

==See also==
* [[List of Apodiformes by population]]
* [[List of birds by flight speed]]
* [[International Swift Conference]]

==References==
{{Reflist|2 |refs=

<ref name=Corrales2013>{{cite journal |last1=Corrales |first1=L. |last2=Bautista |first2=L.M. |last3=SantaMaría |first3=T. |last4=Mas |first4=P. |year=2013 |title=Hole selection by nesting swifts in medieval city-walls of central Spain |journal=Ardeola |volume=60 |issue=2 |pages=291–304  |doi=10.13157/arla.60.2.2013.291 |s2cid=84894013 |url=https://digital.csic.es/bitstream/10261/96963/1/Corrales%20Ardeola60%20p291%202013.pdf |hdl=10261/96963 |hdl-access=free }}</ref>

}}

==Bibliography==
* {{cite book | last= Chantler | first= Phillip |author2=Driessens, Gerald  | year= 2000| title= Swifts: A Guide to the Swifts and Treeswifts of the World |publisher = Pica Press | location = London | isbn =1-873403-83-6 }}
* {{cite book | last= Jobling | first= James A | year= 2010| title= The Helm Dictionary of Scientific Bird Names | url =https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling|publisher = Christopher Helm | location = London | isbn = 978-1-4081-2501-4 }}
* {{cite book | last= Kaufman | first= Kenn | year=2001 | title=Lives of North American Birds|publisher = Houghton Mifflin Harcourt | location = Oxford| isbn =0-618-15988-6 }}

==External links==
{{Commons category|Apodidae}}
*[https://xeno-canto.org/explore?query=apodidae Swift sounds] on xeno-canto.org
*[http://www.swift-conservation.org] Swift Conservation.Org free advice on the natural history and conservation of Apus apus the Common Swift

{{Taxonbar|from=Q26617}}
{{Authority control}}

[[Category:Apodidae|*]]
[[Category:Swifts|*]]
[[Category:Taxa named by Ernst Hartert]]
[[Category:Extant Eocene first appearances]]