Editing Barn swallow (section)

== Status ==
[[File:The barn swallow moment of truth.jpg|thumb|Barn swallow at the moment when its beak touches the water to have a drink in Bagmati River, Nepal|alt=See caption]]
[[File:A reflection flight of barn swallow.jpg|thumb|A reflection flight of barn swallow|alt=See caption]]
The barn swallow has an enormous range, with an estimated global extent of about {{convert|250000000|km2|sqmi|abbr=on}} and a population of 190 million individuals. The species is evaluated as [[least concern]] on the 2019 [[IUCN Red List]],<ref name="iucn status 12 November 2021" /> and has no special status under the Convention on International Trade in Endangered Species of Wild Fauna and Flora ([[CITES]]), which regulates international trade in specimens of wild animals and plants.<ref name= umich>{{cite web |last=Dewey |first=Tanya |author2=Roth, Chava |title=''Hirundo rustica'' |url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Hirundo_rustica.html |year=2002 |work=Animal Diversity Web |publisher=University of Michigan Museum of Zoology| archive-url= https://web.archive.org/web/20071210232505/http://animaldiversity.ummz.umich.edu/site/accounts/information/Hirundo_rustica.html| archive-date= 10 December 2007| url-status= live}}</ref>

This is a species that has greatly benefited historically from forest clearance, which has created the open habitats it prefers, and from human habitation, which have given it an abundance of safe man-made nest sites. There have been local declines due to the use of [[DDT]] in Israel in the 1950s, competition for nest sites with [[house sparrow]]s in the US in the 19th century, and an ongoing gradual decline in numbers in parts of Europe and Asia due to agricultural intensification, reducing the availability of insect food. However, there has been an increase in the population in North America during the 20th century with the greater availability of nesting sites and subsequent range expansion, including the colonisation of northern [[Alberta]].<ref name=Turner/>

A specific threat to wintering birds from the European populations is the transformation by the South African government of a light aircraft runway near [[Durban]] into [[King Shaka International Airport|an international airport]] for the [[2010 FIFA World Cup]]. The roughly {{convert|250|m|yd|abbr=on}} square Mount Moreland reed bed is a night roost for more than three million barn swallows, which represent 1% of the global population and 8% of the European breeding population. The reed bed lies on the flight path of aircraft using the proposed La Mercy airport, and there were fears that it would be cleared because the birds could threaten aircraft safety.<ref name= Guardian>{{cite news|title=World Cup airport 'threatens swallow population' |url=https://www.theguardian.com/travel/2006/nov/16/travelnews.conservationandendangeredspecies.environment |date=16 November 2006 |work=The Guardian |location=UK| archive-url= https://web.archive.org/web/20071203201940/http://www.guardian.co.uk/travel/2006/nov/16/travelnews.conservationandendangeredspecies.environment| archive-date= 3 December 2007 | url-status= live}}</ref><ref name = BirdLife2>{{cite press release | title = 'World Cup 2010' development threatens millions of roosting Barn Swallows| publisher = BirdLife International| date = 16 November 2006| url = http://www.birdlife.org/news/pr/2006/11/La_Mercy_BarnSwallows.html| access-date = 27 November 2007| archive-url= https://web.archive.org/web/20071204005003/http://www.birdlife.org/news/pr/2006/11/La_Mercy_BarnSwallows.html| archive-date= 4 December 2007| url-status= live}}</ref> However, following detailed evaluation, advanced radar technology will be installed to enable planes using the airport to be warned of bird movements and, if necessary, take appropriate measures to avoid the flocks.<ref name=mercy>{{cite news|last=Froneman |first=Albert |author2=Bortle, Jon |author3=Merritt, Ron |title=Draft swallow monitoring and bird aircraft interaction |url=http://eia.dubetradeport.co.za/Documents/Documents/2007Apr23/Draft%20Swallow%20Monitoring%20&%20Bird%20Aircraft%20Interaction%20Apr%202007.pdf |date=April 2007 |work=Environmental Impact Assessment Report |publisher=Dube TradePort Environmental Impact Assessment Information Center|archive-url=https://web.archive.org/web/20080625075752/http://eia.dubetradeport.co.za/Documents/Documents/2007Apr23/Draft%20Swallow%20Monitoring%20%26%20Bird%20Aircraft%20Interaction%20Apr%202007.pdf |archive-date=25 June 2008 |url-status=dead }}</ref>

[[Climate change]] may affect the barn swallow; drought causes weight loss and slow feather regrowth, and the expansion of the [[Sahara]] will make it a more formidable obstacle for migrating European birds. Hot dry summers will reduce the availability of insect food for chicks. Conversely, warmer springs may lengthen the breeding season and result in more chicks, and the opportunity to use nest sites outside buildings in the north of the range might also lead to more offspring.<ref name= BB102>{{cite journal| last=Turner | first=Angela |date=January 2009 | title= Climate change: a Swallow's eye view| journal= British Birds| volume=102 | issue=1 | pages= 3–16 }}</ref>