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Gulls, often referred to as seagulls,〔("Seagull" ). The American Heritage Dictionary〕〔("Seagull" ). Merriam–Webster〕 are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns (family Sternidae) and only distantly related to auks, skimmers, and more distantly to the waders. Until the 21st century, most gulls were placed in the genus ''Larus'', but this arrangement is now known to be polyphyletic, leading to the resurrection of several genera.〔 An older name for gulls is mew, cognate with German ''Möwe'', Danish ''måge'', Dutch ''meeuw'', and French ''mouette''; this term can still be found in certain regional dialects.〔(Webster's Revised Unabridged Dictionary, 1913 )〕〔(The American Heritage Dictionary of the English Language, Fourth Edition )〕〔(Merriam-Webster Online )〕 Gulls are typically medium to large birds, usually grey or white, often with black markings on the head or wings. They typically have harsh wailing or squawking calls, stout, longish bills, and webbed feet. Most gulls, particularly ''Larus'' species, are ground-nesting carnivores, which take live food or scavenge opportunistically. Live food often includes crabs and small fish. Gulls have unhinging jaws which allow them to consume large prey. Apart from the kittiwakes, gulls are typically coastal or inland species, rarely venturing far out to sea. The large species take up to four years to attain full adult plumage, but two years is typical for small gulls. Large white-headed gulls are typically long-lived birds, with a maximum age of 49 years recorded for the herring gull.〔(【引用サイトリンク】title=AnAge entry for Larus argentatus )〕 Gulls nest in large, densely packed noisy colonies. They lay two or three speckled eggs in nests composed of vegetation. The young are precocial, being born with dark mottled down, and mobile upon hatching. Gulls—the larger species in particular—are resourceful, inquisitive and intelligent birds, demonstrating complex methods of communication and a highly developed social structure. For example, many gull colonies display mobbing behaviour, attacking and harassing would-be predators and other intruders.〔Alcock, J. (1998) Animal Behavior: An Evolutionary Approach (7th edition). Sinauer Associates, Inc. Sunderland, Massachusetts. ISBN 0-87893-009-4〕 Certain species (e.g. the herring gull) have exhibited tool use behaviour, using pieces of bread as bait with which to catch goldfish, for example. Many species of gulls have learned to coexist successfully with humans and have thrived in human habitats. Others rely on kleptoparasitism to get their food. Gulls have been observed preying on live whales, landing on the whale as it surfaces to peck out pieces of flesh. ==Description and morphology== Gull species range in size from the little gull, at and , to the great black-backed gull, at and . They are generally uniform in shape, with heavy bodies, long wings, and moderately long necks. The tails of all but three species are rounded; the exceptions being Sabine's gull and swallow-tailed gulls, which have forked tails, and Ross's gull, which has a wedge-shaped tail. Gulls have moderately long legs (certainly longer than the terns) with fully webbed feet. The bill is generally heavy and slightly hooked, with the larger species having stouter bills than the smaller species. The bill colour is often yellow with a red spot for the larger white-headed species and red, dark red or black in the smaller species. The gulls are generalist feeders, indeed they are the least specialised of all the seabirds, and their morphology allows for equal adeptness in swimming, flying, and walking. They are more adept walking on land than most other seabirds, and the smaller gulls tend to be more manoeuvrable while walking. The walking gait of gulls includes a slight side to side motion, something that can be exaggerated in breeding displays. In the air, they are able to hover and they are also able to take off quickly with little space.〔 The general pattern of plumage in adult gulls is a white body with a darker mantle; the extent to which the mantle is darker varies from pale grey to black. A few species vary in this, the ivory gull is entirely white, and some like the lava gull and Heermann's gull have partly or entirely grey bodies. The wingtips of most species are black, which improves their resistance to wear and tear, usually with a diagnostic pattern of white markings. The head of a gull may be covered by a dark hood or be entirely white. The plumage of the head varies by breeding season; in nonbreeding dark-hooded gulls, the hood is lost, sometimes leaving a single spot behind the eye, and in white-headed gulls, nonbreeding heads may have streaking.〔 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「gull」の詳細全文を読む スポンサード リンク
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