Editing Common tern (section)

==Predators and parasites==
Rats will take tern eggs, and may even store large numbers in [[Hoarding (animal behavior)|caches]],<ref name=austin1>{{cite journal |last=Austin |first=O L |year=1948 |title=Predation by the common rat (''Rattus norvegicus'') in the Cape Cod colonies of nesting terns |journal=Bird-Banding |volume=19 |issue=2 |pages=60–65 |doi=10.2307/4510014|jstor=4510014}}</ref> and the [[American mink]] is an important predator of hatched chicks, both in North America, and in [[Scotland]] where it has been [[Introduced species|introduce]]d.<ref name=hume112>Hume (1993) pp. 112–119.</ref> The [[red fox]] can also be a local problem.<ref name= jncc/> Because common terns nest on islands, the most common predators are normally other birds rather than mammals. The [[ruddy turnstone]] will take eggs from unattended nests,<ref name=parkes>{{cite journal |last=Parkes |first=K C |author2=Poole, A |author3=Lapham, H |year=1971 |title=The Ruddy Turnstone as an egg predator |journal=Wilson Bulletin |volume=83 |pages=306–307 |url=http://sora.unm.edu/sites/default/files/journals/wilson/v083n03/p0306-p0308.pdf |access-date=22 February 2013 |archive-date=27 May 2014 |archive-url=https://web.archive.org/web/20140527212553/http://sora.unm.edu/sites/default/files/journals/wilson/v083n03/p0306-p0308.pdf |url-status=live }}</ref><ref name=fara>{{cite journal |last=Farraway |first=A |author2=Thomas, K |author3=Blokpoel, H |year=1986 |title=Common Tern egg predation by Ruddy Turnstones |journal=Condor |url=http://sora.unm.edu/node/103749 |volume=88 |issue=4 |pages=521–522 |doi=10.2307/1368282 |jstor=1368282 |access-date=22 February 2013 |archive-date=21 October 2020 |archive-url=https://web.archive.org/web/20201021191356/https://sora.unm.edu/node/103749 |url-status=live |url-access=subscription }}</ref> and gulls may take chicks.<ref name=houde>{{cite journal |last=Houde |first=P |year=1977 |title=Gull-tern interactions on Hicks Island |journal=Proceedings of the Linnaean Society of New York |volume=73 |pages=58–64}}</ref><ref name=whittam>{{cite journal |last=Whittam |first=R M |author2=Leonard, M L |year=2000 |title=Characteristics of predators and offspring influence on nest defense by Arctic and Common Terns |journal=Condor |url=http://sora.unm.edu/node/105635 |volume=102 |issue=2 |pages=301–306 |doi=10.1650/0010-5422(2000)102[0301:COPAOI]2.0.CO;2 |s2cid=56440470 |access-date=22 February 2013 |archive-date=21 October 2020 |archive-url=https://web.archive.org/web/20201021193142/https://sora.unm.edu/node/105635 |url-status=live |url-access=subscription }}</ref> Great horned owls and [[short-eared owl]]s will kill both adults and chicks, and [[black-crowned night heron]]s will also eat small chicks.<ref name=nisbet>{{cite web |author=Nisbet, Ian C |title=Common Tern (''Sterna hirundo'') |url=http://bna.birds.cornell.edu/bna/species/618/articles/introduction |url-access=subscription |publisher=Cornell Lab of Ornithology |access-date=25 January 2012 |archive-date=7 September 2011 |archive-url=https://web.archive.org/web/20110907090302/http://bna.birds.cornell.edu/bna/species/618/articles/introduction}}</ref><ref name=morris>{{cite journal |last=Morris |first=R D |author2=Wiggins, D A |year=1986 |title=Ruddy Turnstones, Great Horned Owls, and egg loss from Common Tern clutches |journal=Wilson Bulletin |volume=98 |pages=101–109 |url=http://sora.unm.edu/sites/default/files/journals/wilson/v098n01/p0101-p0109.pdf |access-date=22 February 2013 |archive-date=18 July 2015 |archive-url=https://web.archive.org/web/20150718135042/http://sora.unm.edu/sites/default/files/journals/wilson/v098n01/p0101-p0109.pdf |url-status=live }}</ref> [[Merlin (bird)|Merlins]] and [[peregrine falcon]]s may attack flying terns; as with other birds, it seems likely that one advantage of flocking behaviour is to confuse fast-flying predators.<ref name=hume79>Hume (1993) pp. 79–85.</ref>

The common tern hosts [[Bird louse|feather lice]], which are quite different from those found in Arctic terns, despite the close relationship of the two birds.<ref name=Rothschild135>Rothschild & Clay (1953 ) p. 135.</ref> It may also be infected by parasitic worms, such as the widespread ''[[Diphyllobothrium]]'' species, the duck parasite ''[[Ligula intestinalis]]'', and ''[[Schistocephalus]]'' species carried initially by fish. [[Cestoda|Tapeworms]] of the family [[Cyclophyllidea]] may also infect this species. The [[mite]] ''[[Reighardia sternae]]'' has been found in common terns from Italy, North America and China.<ref name=Rothschild194>Rothschild & Clay (1953) pp. 194–197.</ref> A study of 75 breeding common terns found that none carried blood parasites.<ref name=Fiorello>{{cite journal |last=Fiorello |first=Christine V |author2=Nisbet, Ian C T |author3=Hatch, Jeremy J |author4=Corsiglia, Carolyn |author5= Pokras, Mark A |year=2009 |title=Hematology and absence of hemoparasites in breeding Common Terns (''Sterna hirundo'') from Cape Cod, Massachusetts |journal=Journal of Zoo and Wildlife Medicine |volume=40 |issue=3 |pages=409–413 |doi=10.1638/2006-0067.1 |pmid=19746853|s2cid=24882069 }}</ref> Colonies have been affected by [[Fowl cholera|avian cholera]] and [[Psittacosis|ornithosis]],<ref name=nisbet/> and it is possible that the common tern may be threatened in the future by outbreaks of [[avian influenza]] to which it is susceptible.<ref name = BirdLife/> In 1961 the common tern was the first wild bird species identified as infected with avian influenza, the [[Influenza A virus subtype H5N3|H5N3]] variant being found in an outbreak of South African birds.<ref name=olsen2006>{{cite journal |last=Olsen |first=Björn |author2=Munster, Vincent J |author3=Wallensten, Anders |author4=Waldenström, Jonas |author5=Osterhaus, D M E |author6= Fouchier, Ron A M |year=2006 |title=Global patterns of influenza A virus in wild birds |journal=Science |volume=312 |issue=5772 |pages=384–388 |doi=10.1126/science.1122438 |pmid=16627734|citeseerx=10.1.1.177.8707 |bibcode=2006Sci...312..384O|s2cid=7795090 }}</ref>