Editing Swift (bird) (section)

==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.