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The European herring gull (''Larus argentatus'') is a large gull (up to long). One of the best known of all gulls along the shores of western Europe, it was once abundant.〔Gilliard, E. Thomas. (1958). ''Living Birds of the World'', p. 174. Doubleday & Company, New York.〕 It breeds across Northern Europe, Western Europe, Central Europe, Eastern Europe, Scandinavia and the Baltic states. Some European herring gulls, especially those resident in colder areas, migrate further south in winter, but many are permanent residents, e.g. in the British Isles, Iceland, or on the North Sea shores. European herring gulls have a varied diet, including fish, crustaceans and dead animals as well as some plants. While herring gull numbers appear to have been harmed in recent years, possibly by fish population declines and competition, they have proved able to survive in human-adapted areas, and can often be seen in towns acting as a scavenger. ==Taxonomy== The taxonomy of the herring gull / lesser black-backed gull complex is very complicated, different authorities recognising between two and eight species. This group has a ring distribution around the Northern Hemisphere. Differences between adjacent forms in this ring are fairly small, but by the time the circuit is completed, the end members, herring gull and lesser black-backed gull, are clearly different species. The terminal forms don't interbreed even though they coexist in the same localities.〔Mayr, Ernst. 1964. "Systematics and the Origin of Species." Dover Publications, Inc. New York ISBN 0-486-21212-2〕 The Association of European Rarities Committees recognises six species: * European herring gull, ''Larus argentatus'' * American herring gull, ''Larus smithsonianus'' * Caspian gull, ''Larus cachinnans'' * Yellow-legged gull, ''Larus michahellis'' * Vega gull, ''Larus vegae'' * Armenian gull, ''Larus armenicus'' 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「European herring gull」の詳細全文を読む スポンサード リンク
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