Editing Parasitic jaeger

{{Short description|Species of bird}}
{{Speciesbox
| image = Arctic Skua 1.jpg
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=BirdLife International |date=2018 |title=''Stercorarius parasiticus'' |volume=2018 |page=e.T22694245A132535550 |doi=10.2305/IUCN.UK.2018-2.RLTS.T22694245A132535550.en |access-date=7 September 2022}}</ref>
| status2 = EN
| status2_system = IUCN3.1
| status2_ref = <ref name="iucn status 12 November 2021"/>(Europe)
| genus = Stercorarius
| species = parasiticus
| authority = ([[Carl Linnaeus|Linnaeus]], 1758)
| range_map = Stercorarius parasiticus map.svg
| synonyms = ''Larus parasiticus'' {{small|Linnaeus,&nbsp;1758}}
}}

The '''parasitic jaeger''' (North America) or '''Arctic skua''' (Europe) ('''''Stercorarius parasiticus'''''), is a [[seabird]] in the [[skua]] family Stercorariidae. It is a migratory species breeding in Northern [[Scandinavia]], [[Scotland]], [[Iceland]], [[Greenland]], [[Northern Canada]], [[Alaska]], and [[Siberia]] and winters across the southern hemisphere. [[Kleptoparasitism]] is a major source of food for this species during migration and winter, and is where the name is derived from.

==Taxonomy==
The parasitic jaeger was [[Species description|formally described]] in 1758 by the Swedish naturalist [[Carl Linnaeus]] in the [[10th edition of Systema Naturae|tenth edition]] of his ''[[Systema Naturae]]'' under the [[binomial nomenclature|binomial name]] ''Larus parasiticus''.<ref>{{cite book | last=Linnaeus | first=Carl | author-link=Carl Linnaeus | year=1758 | title=Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis | volume=1 | edition=10th | pages=136–137 | publisher=Laurentii Salvii | location=Holmiae (Stockholm) | language=Latin | url=https://www.biodiversitylibrary.org/page/727041 | access-date=2024-07-21 | archive-date=2023-04-22 | archive-url=https://web.archive.org/web/20230422142657/https://www.biodiversitylibrary.org/page/727041 | url-status=live }}</ref> Linnaeus specified the [[type locality (biology)|type locality]] as "within the Tropic of Cancer of Europe, America and Asia" but this is now restricted to the Swedish coastline.<ref>{{cite book | editor-last=Peters | editor-first=James Lee | editor-link=James L. Peters | year=1934 | title=Check-List of Birds of the World | volume=2 | publisher=Harvard University Press | place=Cambridge, Massachusetts | pages=311–312 | url=https://www.biodiversitylibrary.org/page/14483124 | access-date=2024-07-21 | archive-date=2024-07-21 | archive-url=https://web.archive.org/web/20240721095727/https://www.biodiversitylibrary.org/page/14483124 | url-status=live }}</ref> The parasitic jaeger is now placed with the six other skuas in the genus ''[[Stercorarius]]'' that was introduced in 1760 by the French zoologist [[Mathurin Jacques Brisson]]. The species is considered to be [[monotypic]]: no [[subspecies]] are recognised.<ref name=ioc>{{cite web | editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | editor3-last=Rasmussen | editor3-first=Pamela | editor3-link=Pamela C. Rasmussen | date=December 2023 | title=Noddies, gulls, terns, auks | work=IOC World Bird List Version 14.1 | url=https://www.worldbirdnames.org/bow/gulls/ | publisher=International Ornithologists' Union | access-date=21 July 2024 | archive-date=8 August 2019 | archive-url=https://web.archive.org/web/20190808171159/https://www.worldbirdnames.org/BOW/gulls/ | url-status=live }}</ref> The genus name ''Stercorarius'' is [[Latin]] and means "of dung"; the food disgorged by other birds when pursued by skuas was once thought to be excrement. The specific ''parasiticus'' is from Latin and means "parasitic".<ref>{{cite book |last=Jobling |first=James A |url=https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling |title=The Helm Dictionary of Scientific Bird Names |publisher=Christopher Helm |year=2010 |isbn=978-1-4081-2501-4 |location=London |pages=[https://archive.org/stream/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling#page/n292/mode/1up 292], [https://archive.org/stream/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling#page/n365/mode/1up 365]}}</ref> The word "jaeger" is the [[German language|German]] word ''Jäger'', meaning "hunter".<ref name="OEDjaeger">{{Cite OED|Jaeger}}</ref> The English "skua" comes from the [[Faroese language|Faroese]] name ''skúgvur'' {{IPA|fo|ˈskɪkvʊər|}} for the [[great skua]], with the island of [[Skúvoy]] known for its colony of that bird. The general Faroese term for skuas is ''kjógvi'' {{IPA|fo|ˈtʃɛkvə|}}.<ref name="OEDskua">{{Cite OED|Skua}}</ref>

==Description==
[[File:Stercorarius parasiticus-pjt.jpg|thumbnail|Dark morph (Iceland)]]
Identification is complicated by similarities to [[long-tailed jaeger]] and [[pomarine jaeger]], and the existence of three colour [[Polymorphism (biology)|morphs]]. Small for a skua, the parasitic jaeger measures {{convert|41|-|48|cm|in|frac=2|abbr=on}} in length, {{convert|107|-|125|cm|in|frac=2|abbr=on}} in wingspan and weighs {{convert|300|-|650|g|lboz|abbr=on}}.<ref name=arkive>{{cite web |url=http://www.arkive.org/parasitic-jaeger/stercorarius-parasiticus/#text=Facts |title=Parasitic jaeger |year=2011 |access-date=2011-10-20 |archive-url=https://web.archive.org/web/20111106153214/http://www.arkive.org/parasitic-jaeger/stercorarius-parasiticus/#text=Facts |archive-date=2011-11-06 |url-status=dead }}</ref><ref name=CRC/> The tail streamer of the breeding adult accounts for about {{convert|7|cm|in|frac=2|abbr=on}} of their length. Light-morph adults have a brown back, mainly white underparts and dark primary wing feathers with a white "flash". The head and neck are yellowish-white with a black cap and there is a pointed central tail projection. Dark-morph adults are dark brown, and intermediate-phase birds are dark with somewhat paler underparts, head and neck. All morphs have the white wing flash.
[[File:ArcticSkua3.jpg|thumb|An immature parasitic jaeger]]
Identification of juveniles is even more problematic, and it is difficult to separate parasitic jaegers from long-tailed jaegers. Parasitic jaegers are bulkier, shorter-winged, and less tern-like than long-tailed jaegers. They are usually warmer toned, with browner shades, rather than grey. However, they show the same wide range of plumage variation. The flight is more [[falcon]]-like. The parasitic jaeger is the most common of the three jaeger species seen from shore.

The typical call of these birds is a nasal mewing sound, repeated a few times in display. Their alarm call is a shorter sound.

==Distribution and habitat==
This species breeds in the north of [[Palearctic|Eurasia]] and North America, with significant populations as far south as northern [[Scotland]], in [[Shetland]] and [[Orkney]], the [[Outer Hebrides]], [[Sutherland]], [[Caithness]], and some islands in [[Argyll and Bute|Argyll]]. Birds in North America breed in [[Alaska]], [[Yukon]], the [[Northwest Territories]], [[Nunavut]], the [[Hudson Bay]] coast, and parts of [[Northern Quebec]] and [[Nunatsiavut]].<ref name=bow>{{cite journal | last1=Wiley | first1=R.H. | last2=Lee | first2=D.S. | date=2020 | title=Parasitic Jaeger (''Stercorarius parasiticus''), version 1.0 | editor-last=Billerman | editor-first=S.M. | journal=Birds of the World | location=Ithaca, NY | publisher=Cornell Lab of Ornithology | doi=10.2173/bow.parjae.01 | url=https://doi.org/10.2173/bow.parjae.01 | access-date=20 July 2024 | url-access=subscription | archive-date=3 October 2024 | archive-url=https://web.archive.org/web/20241003211535/https://birdsoftheworld.org/bow/species/parjae/1.0/introduction | url-status=live }}</ref>

The parasitic jaeger is a [[bird migration|migrant]], wintering at sea in the tropics and southern oceans. While much of the migration is over sea, overland spring migration occurs in the [[Canning River (Alaska)|Canning River Valley]], [[Alaska]], and overland fall migration occurs from northern [[Russia]] to the [[Persian Gulf]] among Eurasian populations, and over the [[Great Lakes]] (particularly [[Lake Ontario]]) among American populations.<ref>{{Cite journal |last=Sherony |first=Dominic F. |date=1999 |title=The Fall Migration of Jaegers on Lake Ontario |url=https://www.jstor.org/stable/4514379 |journal=Journal of Field Ornithology |volume=70 |issue=1 |pages=33–41 |jstor=4514379  |access-date=2022-09-02 |archive-date=2022-09-02 |archive-url=https://web.archive.org/web/20220902030715/https://www.jstor.org/stable/4514379 |url-status=live }}</ref>

==Behavior==
===Breeding===
[[File:Stercorarius parasiticus MWNH 0303.JPG|left|thumb|Eggs, Collection [[Museum Wiesbaden]]]]
Nesting occurs on dry [[tundra]], higher [[fell]]s, and islands. [[Clutch (eggs)|Clutches]] consist of up to four olive-brown eggs. Jaegers are usually silent except for mewing and wailing notes while on the breeding grounds. Like other skuas, it will fly at the head of a human or fox approaching its nest.

===Feeding===
This bird will feed on rodents, insects, eggs, chicks and small birds in the breeding season, but the majority of its diet (especially in winter and on migration) is made up of food that it acquires by robbing other [[bird]]s (primarily [[gull]]s and [[tern]]s) of their catches in an act called [[kleptoparasitism]].

==Conservation status==
In 2018, ''Stercorarius parasiticus'' was regionally uplisted to Endangered in Iceland, from Least Concern in 2000, after their numbers declined drastically in the early 2000s.<ref>https://www.ni.is/node/27109 {{Webarchive|url=https://web.archive.org/web/20221208203427/https://www.ni.is/node/27109 |date=2022-12-08 }} Kristinn Haukur Skarphéðinsson, "Kjói (''Stercorarius parasiticus'')," Icelandic Institute of Natural History, last updated October 2018.</ref> It is globally listed as Least Concern.

== References ==
{{Reflist|refs=
<ref name=CRC>{{cite book |editor-last=Dunning |editor-first=John B. Jr. |title=CRC Handbook of Avian Body Masses |publisher=CRC Press |year=1992 |isbn=978-0-8493-4258-5}}</ref>
}}

== External links ==
{{Commons category|Stercorarius parasiticus}}
{{Wikispecies|Stercorarius parasiticus}}
* Arctic skua - [http://sabap2.adu.org.za/docs/sabap1/307.pdf Species text in The Atlas of Southern African Birds]
* {{usurped|1=[https://web.archive.org/web/20090616212742/http://www.handaskuas.org/ Arctic skua information and photos at the Handa Island Skua Project]}}
* [[RSPB]] [http://www.rspb.org.uk/birds/guide/a/arcticskua/index.asp Birds by Name: Arctic skua]
* {{InternetBirdCollection|arctic-skua-stercorarius-parasiticus|Arctic skua}}
* {{VIREO|Parasitic+jaeger}}
* {{IUCN_Map|22694245/166270832|Stercorarius parasiticus}}
* {{Xeno-canto species|Stercorarius|parasiticus|Parasitic jaeger}}

{{Taxonbar|from=Q203053}}
{{Authority control}}

[[Category:Skuas]]
[[Category:Cosmopolitan birds]]
[[Category:Birds of the Arctic]]
[[Category:Holarctic birds]]
[[Category:Birds of Scandinavia]]
[[Category:Birds of Iceland]]
[[Category:Birds of Europe]]
[[Category:Birds of Southern Africa]]
[[Category:Birds described in 1758]]
[[Category:Taxa named by Carl Linnaeus]]