银鸥
维基百科，自由的百科全书
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 Herring Gull Larus argentatus argenteus. English south coast. Standing on spikes designed to prevent gulls from landing. Larger version |
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| Larus argentatus Pontopiddan, 1763 |
银鸥, Larus argentatus, is a large 鸥 which breeds across 北美洲 欧洲和亚洲。It migrates further south in winter. Some are permanent residents on the lower Great Lakes and the east coast of North America. Herring Gulls are also abundant around inland garbage dumps, and some have even adapted to life in inland cities.
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 Association of European Taxonomic Committees recognises six species:
- 银鸥, Larus argentatus
- American Herring Gull, Larus smithsonianus
- 里海鸥, Larus cachinnans
- 黄脚银鸥, Larus michahelis
- East Siberian Herring Gull, Larus vegae
- Armenian Gull, Larus armenicus
Adults are easily identified by their size, pale grey back and the red spot on the beak. Legs are pink at all ages. The bird depicted is the western European race Larus argentatus argenteus. The Scandinavian race L. a. argentatus is slightly larger and darker, with more white in the wing tips.
The North American American Herring Gull is similar to argentatus, except that immature birds tend to be darker and more uniformly brown.
These are omnivores like most Larus gulls, and will scavenge on rubbish tips and elsewhere, as well as seeking suitable small prey in fields or on the coast, or robbing plovers or lapwings of their catches.
Eggs, usually three, are laid on the ground or cliff ledges in colonies, and are defended vigorously by this large gull. The loud laughing call is well-known in the northern hemisphere.
Parasites of Herring gulls include the fluke Microphallus piriformes.
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