California gull | |
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California gull at Palo Alto Duck Pond, [1] Baylands Nature Preserve, Palo Alto, California | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Charadriiformes |
Family: | Laridae |
Genus: | Larus |
Species: | L. californicus |
Binomial name | |
Larus californicus Lawrence, 1854 | |
Subspecies | |
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The California gull (Larus californicus) is a medium-sized gull, smaller on average than the herring gull, but larger on average than the ring-billed gull (though it may overlap in size greatly with both). It lives not just in California, but up and down the entire Western coast of North America, and has breeding ground inland. The yellow bill has a black ring.
Adults are similar in appearance to the herring gull, but have a smaller yellow bill with a black ring, yellow legs, brown eyes and a more rounded head. The body is mainly white with grey back and upper wings. They have black primaries with white tips. Immature birds are also similar in appearance to immature herring gulls, with browner plumage than immature ring-billed gulls. Length can range from 46 to 55 cm (18 to 22 in), the wingspan 122–137 cm (48–54 in)[ citation needed ] and body mass can vary from 430 to 1,045 g (0.948 to 2.304 lb). [4]
Their breeding habitat is lakes and marshes in interior western North America from the Northwest Territories, Canada south to eastern California and Colorado. [5] They nest in colonies, sometimes with other birds. The nest is a shallow depression on the ground lined with vegetation and feathers. The female usually lays 2 or 3 eggs. Both parents take turns feeding their chicks.
They are migratory, most moving to the Pacific coast in winter. It is only then that this bird is regularly found in western California. [5]
These birds forage in flight or pick up objects while swimming, walking or wading. They mainly eat insects, fish and the eggs and young of other birds, especially ducklings. [6] Opportunistic feeders, they also scavenge at garbage dumps, marinas and docks. They frequently beg for food at public beaches, parks and other locations where people will hand feed them. They have been known to steal food directly from people at picnics and outdoor restaurants. They may follow fishing boats or plows in fields for insects stirred up by this activity.
California gulls are also known to eat various vegetables and fruits, particularly cherries. [6] As a result, it may be regarded as a crop pest. [7]
This is the state bird of Utah, [8] remembered for assisting Mormon settlers in dealing with a plague of Mormon crickets. [9] A monument in Salt Lake City commemorates this event, known as the "Miracle of the Gulls". [9]
There are two subspecies recognized, the nominate from the Great Basin to central Montana and Wyoming, and the slightly larger, paler L. c. albertaensis with a more northerly distribution, ranging from Great Slave Lake onto the Great Plains of western Manitoba and South Dakota. [10] Although these subspecies are not well distinguishable by mtDNA allozyme variation, [11] they breed true and the low genetic divergence can be explained by separation during the Pleistocene and renewed contact in Montana during more recent times. [12]
In California, the California gull recently held the protected status California Species of Special Concern due to declining numbers at their historic California breeding colony at Mono Lake. However, in recent decades this species has begun to breed in the southern portion of San Francisco Bay, where it did not historically breed, and has undergone exponential population growth. These California gulls now inhabit large, remote salt-production ponds and levees and have a very large food source provided by nearby landfills from San Francisco, San Jose and other urban areas, all the way up into the Sacramento area. The South Bay California gull population has grown from less than 1,000 breeding birds in 1982 to over 33,000 in 2006. This population boom has resulted in large resident flocks of gulls that will opportunistically prey on other species, particularly the eggs and nestlings of other birds. Seriously threatened birds that share the same South Bay habitat include the snowy plover and California least tern, while less-threatened birds including black-necked stilts, American avocets, Forster's terns, and Caspian terns are also preyed upon by the abnormally large flocks of California gulls. Efforts are underway to reduce habitat for this species and find other ways to disperse the large numbers of gulls. [13] Contrary to its name, the California Gull is the state bird of Utah.
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and distantly related to auks, and even more distantly to waders. Until the 21st century, most gulls were placed in the genus Larus, but that arrangement is now considered polyphyletic, leading to the resurrection of several genera. An older name for gulls is mews, which is cognate with German Möwe, Danish måge, Swedish mås, Dutch meeuw, Norwegian måke/måse, and French mouette, and can still be found in certain regional dialects.
Larus is a large genus of gulls with worldwide distribution.
The common gull or sea mew is a medium-sized gull that breeds in the Palearctic. The closely related short-billed gull is sometimes included in this species, which may be known collectively as "mew gull". Many common gulls migrate further south in winter. There are differing accounts as to how the species acquired its vernacular name.
The European herring gull is a large gull, up to 66 cm (26 in) long. It breeds throughout the northern and western coasts of Europe. Some European herring gulls, especially those resident in colder areas, migrate further south in winter, but many are permanent residents, such as in Ireland, Britain, Iceland, or on the North Sea shores. They have a varied diet, including fish, crustaceans, as well as some plants, and are also scavengers, consuming carrion and food left by or stolen from humans.
The great black-backed gull is the largest member of the gull family. Described by the Cornell Lab of Ornithology as "the king of the Atlantic waterfront", it is a very aggressive hunter, pirate, and scavenger. It breeds on the European and North American coasts and islands of the North Atlantic and is fairly sedentary, though some move farther south or inland to large lakes and reservoirs. The adult great black-backed gull has a white head, neck and underparts, dark grey wings and back, pink legs and yellow bill.
The lesser black-backed gull is a large gull that breeds on the Atlantic coasts of Europe. It is migratory, wintering from the British Isles south to West Africa. However, it has increased dramatically in North America, especially along the east coast. Formerly just a winter visitor to North America, it has increased and occurs in large numbers some winters and birds are now recorded year-round. However, there is serious concern about decline in many parts of its range. The species is on the UK Amber List because the UK is home to 40 per cent of the European population and more than half of these are found at fewer than ten breeding sites.
The little gull, is a species of gull belonging to the family Laridae which is mainly found in the Palearctic with some colonies in North America. It breeds on freshwaters and spends winters at sea. It is the smallest species of gull in the world and the only species in the monospecific genus Hydrocoloeus.
The Iceland gull is a medium-sized gull that breeds in the Arctic regions of Canada and Greenland, but not in Iceland, where it is only seen during winter. The genus name is from Latin larus, which appears to have referred to a gull or other large seabird. The specific name glaucoides denotes its resemblance to Larus glaucus, a synonym of Larus hyperboreus, the glaucous gull; -oides is Ancient Greek and means "resembling".
Bonaparte's gull is a member of the gull family Laridae found mainly in northern North America. At 28 to 38 cm in length, it is one of the smallest species of gull. Its plumage is mainly white with grey upperparts. During breeding season, Bonaparte's gull gains a slaty-black hood. The sexes are similar in appearance.
The ring-billed gull is a medium-sized gull. The genus name is from Latin Larus which appears to have referred to a gull or other large seabird. The specific delawarensis refers to the Delaware River.
The gull-billed tern, formerly Sterna nilotica, is a tern in the family Laridae. It is widely distributed and breeds in scattered localities in Europe, Asia, northwest Africa, and the Americas. The Australian gull-billed tern was previously considered a subspecies.
The yellow-legged gull is a large gull found in Europe, the Middle East and North Africa, which has only recently achieved wide recognition as a distinct species. It was formerly treated as a subspecies of either the Caspian gull L. cachinnans, or more broadly as a subspecies of the herring gull L. argentatus. The genus name is from Latin Larus which appears to have referred to a gull or other large seabird, and the species name honours the German zoologist Karl Michahelles.
Sabine's gull also known as the fork-tailed gull or xeme, is a small gull. It is the only species placed in the genus Xema. It breeds in colonies on coasts and tundra, laying two or three spotted olive-brown eggs in a ground nest lined with grass. Sabine's gull is pelagic outside the breeding season. It takes a wide variety of mainly animal food, and will eat any suitable small prey.
Forster's tern is a tern in the family Laridae. The genus name Sterna is derived from Old English "stearn", "tern", and forsteri commemorates the naturalist Johann Reinhold Forster.
The silver gull is the most common gull of Australia. It has been found throughout the continent, but particularly at or near coastal areas. It is smaller than the Pacific gull, which also lives in Australia.
Heermann's gull is a gull resident in the United States, Mexico and extreme southwestern British Columbia, nearly all nesting on Isla Rasa in the Gulf of California. They are usually found near shores or well out to sea, very rarely inland. The species is named after Adolphus Lewis Heermann, nineteenth-century explorer and naturalist.
Thayer's gull is a subspecies of the Iceland gull. It is a large gull native to North America.
The Andean gull is a species in subfamily Larinae of the family Laridae, the gulls, terns, and skimmers. It is found in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru.
The American herring gull or Smithsonian gull is a large gull that breeds in North America, where it is treated by the American Ornithological Society as a subspecies of herring gull.
Gravel Island National Wildlife Refuge is a National Wildlife Refuge located off the Door Peninsula in Wisconsin. Founded in 1913, the refuge consists of two Lake Michigan islands that act as nesting grounds for native bird species. It is inhabited by large colonies of shore birds and waterfowl in addition to hosting a pair of great black-backed gulls, one of farthest westward breeding sites of the species.