GULL

any of more than 40 species of heavily built, web-footed seabirds of the subfamily Larinae, family Laridae. Gulls are most abundant as breeders in the Northern Hemisphere, which has about 30 species in temperate to arctic regions. Those nesting inland usually go to coasts in winter. Adult gulls are mainly gray or white, with variable head markings. In breeding season the head is either pure white or solidly black, gray, or brown; it becomes streaked or smudgy in winter. The bill is strong and slightly hooked, showing, in some species, a spot of colour. Bill and leg colours help to distinguish species, as do wing patterns. Gulls scavenge for food, taking insects, mollusks, and crustaceans on beaches; worms and grubs in plowed fields; and fish and garbage from ships and along shores. Some of the larger gulls prey on the eggs and young of other birds, including their own kind. Several genera are usually recognized for certain specialized gulls, but many authorities place these in the broad genus Larus. The black-headed gull (Larus ridibundus), a dark-headed bird with crimson legs, breeds in Eurasia and Iceland and winters south to India and the Philippines, commonly feeding in fields, where its chief food is insects. Bonaparte's gull (L. philadelphia), of North America, has a black head and bill, a gray mantle, and pinkish to reddish legs. It nests in trees and hawks over ponds for insects. In the winter, at sea, it may plunge for fish. The California gull (L. californicus), of North America, breeds inland and winters on the Pacific coast. This species is credited with saving the crops of early Mormon settlers in the Salt Lake City region from destruction by the Mormon cricket, a long-horned grasshopper; it is the state bird of Utah. Franklin's gull (L. pipixcan) breeds in large colonies on inland marshes of North America and winters on the Pacific coast of South America. Herring gull (Larus argentatus) The glaucous gull (L. hyperboreus), of northern seas, is mostly white with pinkish legs and a yellow bill with a red spot. Sometimes it winters as far south as Hawaii and the Mediterranean Sea. The great black-backed gull (L. marinus), with a wingspread of 1.6 m (63 inches), is the largest gull. It is nearly circumpolar but does not occur between Labrador and Japan. The herring gull (L. argentatus; see photograph) is by far the most common of the Atlantic gulls. A bird of the Northern Hemisphere, it has a gray mantle, flesh-coloured legs and feet, and black-and-white-spotted wing tips. Herring gull populations are generally increasing as a result of expanding food supplies, chiefly garbage and sewage in or near coastal waters; herring gulls are primarily scavengers. The kelp gull (L. dominicanus) is a very wide-ranging, black-backed species of the Southern Hemisphere, including Antarctica. The laughing gull (L. atricilla), a medium-sized bird with a black head, red bill, and red feet, often gives vent to a strident, laughing call. It breeds from Maine to northern South America and winters south to Brazil, often on fresh waters far inland. It is the only gull that breeds both in the Caribbean area and in the North Atlantic Ocean. The little gull (L. minutus), of Europe and occasionally North America, a black-headed species with a wingspread of about 60 cm (24 inches), is the smallest gull. The Pacific gull (L. pacificus) breeds in the region of Tasmania and southern Australia. The ring-billed gull (L. delawarensis) is common on inland lakes in North America and often gathers in large flocks to feed on plowed fields. The sooty gull (L. hemprichi), of the western Indian Ocean, has a dark brown hood and a grayish brown mantle. Ross's gull (Rhodostethia rosea) is an attractive, pinkish white bird that breeds in northern Siberia and wanders widely over the Arctic Ocean. Sabine's gull (Xema sabini), abounding in the Arctic, has a forked tail and a habit of running and picking up food like a plover. The swallow-tailed gull (Creagrus furcatus), of the Galpagos Islands, is a striking bird, the only gull with a deeply forked tail. See also kittiwake.