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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Breeding Migration Year-round Nonbreeding |
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 with both). It lives not just in California, but up and down the entire Western coast of North America, and has breeding ground inland.
Adults are similar in appearance to the herring gull, but with brown eyes, yellow legs, and a more rounded head. The body is mainly white with grey back and upper wings. The bill is yellow with a black ring and red spot near the tip. 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, with 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, in some areas 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 at one time 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]
The black-necked grebe or eared grebe is a member of the grebe family of water birds. It was described in 1831 by Christian Ludwig Brehm. There are currently three accepted subspecies, including the nominate subspecies. Its breeding plumage features distinctive ochre-coloured feathers which extend behind its eye and over its ear coverts. The rest of the upper parts, including the head, neck, and breast, are coloured black to blackish brown. The flanks are tawny rufous to maroon-chestnut, and the abdomen is white. In its non-breeding plumage, this bird has greyish-black upper parts, including the top of the head and a vertical stripe on the back of the neck. The flanks are also greyish-black. The rest of the body is a white or whitish colour. The juvenile has more brown in its darker areas. The subspecies californicus can be distinguished from the nominate by the former's usually longer bill. The other subspecies, P. n. gurneyi, can be differentiated by its greyer head and upper parts and by its smaller size. P. n. gurneyi can also be told apart by its lack of a non-breeding plumage. This species is present in parts of Africa, Eurasia, and the Americas.
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.
Terns are seabirds in the family Laridae, subfamily Sterninae, that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated in eleven genera in a subgroup of the family Laridae, which also includes several genera of gulls and the skimmers (Rynchops). They are slender, lightly built birds with long, forked tails, narrow wings, long bills, and relatively short legs. Most species are pale grey above and white below with a contrasting black cap to the head, but the marsh terns, the black-bellied tern, the Inca tern, and some noddies have dark body plumage for at least part of the year. The sexes are identical in appearance, but young birds are readily distinguishable from adults. Terns have a non-breeding plumage, which usually involves a white forehead and much-reduced black cap.
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.
The laughing gull is a medium-sized gull of North and South America. Named for its laugh-like call, it is an opportunistic omnivore and scavenger. It breeds in large colonies mostly along the Atlantic coast of North America, the Caribbean, and northern South America. The two subspecies are L. a. megalopterus — which can be seen from southeast Canada down to Central America — and L. a. atricilla, which appears from the West Indies to the Venezuelan islands. The laughing gull was long placed in the genus Larus until its present placement in Leucophaeus.
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 slender-billed gull is a mid-sized gull which breeds very locally around the Mediterranean and the north of the western Indian Ocean on islands and coastal lagoons. Most of the population is somewhat migratory, wintering further south to as far as North Africa and India. A few birds have wandered to western Europe. A vagrant individual was reportedly seen on Antigua, April 24, 1976.
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 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.
The Caspian gull is a large gull and a member of the herring and lesser black-backed gull complex. The scientific name is from Latin. Larus appears to have referred to a gull or other large seabird, and cachinnans means 'laughing', from cachinnare 'to laugh'.
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.
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.