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Heuglin's gull or Siberian gull (''Larus heuglini'') is a seabird in the genus ''Larus''. It is closely related to the lesser black-backed gull (''Larus fuscus'') and is often classified as a subspecies of it. It has also been included within the herring gull (''Larus argentatus''). Birds in the eastern part of Heuglin's gull's range are often paler grey above and are frequently considered to be a separate subspecies ''Larus heuglini taimyrensis'' (Taimyr gull). Another possibility is that they are a result of hybridization between Heuglin's gulls and Vega gulls. Heuglin's gulls breed in the tundra of northern Russia from the Kola Peninsula east to the Taymyr Peninsula. They are regularly reported from Finland and may breed there. They migrate south to winter in Southwest Asia, the Indian Subcontinent, East Asia, and East Africa. Small numbers are seen in Southeast Asia, it has been recorded in South Africa and it may occur as a vagrant in Western Europe. They are large gulls with a rounded head, strong bill and long legs and wings. Length is from , wingspan is from and body mass is from .〔''Gulls: Of North America, Europe, and Asia'' by Klaus Malling Olsen & Hans Larsson. Princeton University Press (2004). ISBN 978-0691119977.〕 Among standard measurements, the wing chord is , the bill is and the tarsus is .〔 The back and wings are dark grey, variable in shade but often similar to the ''graelsii'' race of the slightly smaller lesser black-backed gull. In winter the head is only lightly streaked with brown but there is heavier streaking on the hindneck. The legs are usually yellow but can be pink. Moulting takes place later than in most of their relatives so birds still have unstreaked heads and worn primaries in September and October. The primary feathers may not be fully grown until February or March when the head is still streaked. They feed mainly on molluscs, worms, and crustaceans. == References == * Paul Doherty & Bill Oddie (2001) ''Gulls: A Video Guide to the Gulls of Europe, Asia & North America''. Videocassette. Bird Images. * Klaus Malling Olsen & Hans Larsson (2003) ''Gulls of North America, Europe, and Asia'', Princeton University Press. * Craig Robson (2002) ''A Field Guide to the Birds of South-East Asia''. New Holland, London. * Adrian Skerrett, Ian Bullock & Tony Disley (2001), ''Birds of Seychelles'', Christopher Helm, London. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Heuglin's gull」の詳細全文を読む スポンサード リンク
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