Editing Chimney swift (section)

==Taxonomy and systematics==
When [[Carl Linnaeus]] first described the chimney swift in 1758, he named it {{nowrap|''Hirundo pelagica''}}, believing it to be a [[swallow]].<ref name = "Fieldiana"/> This misconception continued well into the 1800s, with ornithologists calling it "American Swallow" (e.g. [[Mark Catesby]])<ref name = "Feduccia"/> or "Chimney Swallow" (e.g. [[John James Audubon]]).<ref name = "Audubon"/> In 1825, [[James Francis Stephens]] moved this and other small, short-tailed [[New World]] swifts to the genus ''[[Chaetura]]'', where it has since remained, although some authorities in the 1800s assigned it to a variety of now obsolete genera.<ref name = "Ridgway"/> It has no [[subspecies]].<ref name = "Clements"/> The chimney swift's closest relative is [[Vaux's swift]] (''C. vauxi''). Scientists believe that the two species [[Allopatric speciation|evolved from a common ancestor]] that was forced to North America's southeastern and southwestern corners by glacial advances. Separated for millennia by vast [[ice sheet]]s, the survivors evolved into two species which are still separated by a wide gap across the continent's midsection.<ref name = "Newton"/> It is also closely related to the [[Chapman's swift]] (''C. chapmani''); in the past, the three were sometimes treated as a single species.<ref name = "HBW443"/>

The chimney swift's genus name, ''Chaetura'', is a combination of two [[Ancient Greek]] words: ''chaite'', which means "bristle" or "spine", and ''oura'' which means "tail". This is an apt description of the bird's tail, as the shafts of all ten tail [[feather]]s ([[rectrices]]) end in sharp, protruding points.<ref name = "Kyle15"/> The [[specific name (zoology)|specific name]] ''pelagica'' is derived from the Greek word ''pelagikos'', which means "of the sea".<ref name = "Helm"/> This is thought to be a reference to its nomadic lifestyle rather than to any reference to the sea,<ref name = "DunneHowTo"/> a theory strengthened by the later assignment of the specific name ''pelasgia'' (after the nomadic [[Pelasgians|Pelasgi tribe]] of [[ancient Greece]]) to the same species by other ornithologists.<ref name = "Helm"/> Its common name refers to its preferred nesting site and its speedy flight.<ref name = "Fergus"/>