Saunders's gull | |
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Summer plumage | |
Winter plumage | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Charadriiformes |
Family: | Laridae |
Genus: | Saundersilarus Dwight, 1926 |
Species: | S. saundersi |
Binomial name | |
Saundersilarus saundersi (Swinhoe, 1871) | |
Synonyms | |
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Saunders's gull (Saundersilarus saundersi) or Chinese black-headed gull, [1] is a species of gull in the family Laridae. It is found in China, Japan, North Korea, South Korea, Macau, Russia, Taiwan, and Vietnam. [1] Its natural habitats are estuarine waters and intertidal marshes. As with many other gulls, it has traditionally been placed in the genus Larus , but based on phylogenetic work some have moved it to Chroicocephalus , while others argue it is sufficiently distinct for placement in the monotypic Saundersilarus. [2] In 2023, this transfer was accepted by the International Ornithologists' Union. [3]
It is threatened by habitat loss, particularly by conversion of saltmarsh to agricultural land or fish farms, and industrial development including oil extraction. [4] One of its few remaining strongholds are the Yancheng Coastal Wetlands, which hosts about 20% of the world's population.
Saunders's gull is named after the British ornithologist Howard Saunders. [5]
This is a very small species of gull with a length of just 33 cm (13 in) and, among gulls, only the little gull is smaller. Adults have a black hood and nape during the breeding season. [6] It is very pale with a white body and tail, pale grey wings. Non-breeding birds have a mottled grey hood and nape, and white-tipped wings with black markings on the primaries. Immatures are distinguished by having a narrow black tail band and some dark mottling on the upperwing. The legs are dark red-brown, and the short bill is black; the body is squat. [4] [7]
Saunders's gull breeds in eastern China and the west coast of Korea. It breeds in saltmarshes dominated by the Suaeda species Suaeda glauca. It overwinters in southern China, Hong Kong, Macau, Taiwan, South Korea, southwestern Japan and Vietnam. Its winter habitats are estuaries and aquaculture ponds and some populations move inland to lakes and marshes. [7]
Saunders's gull catches its prey by flying above the ground at about ten metres (yards) and dropping swiftly on any suitable prey it finds. In this way it catches mudskippers, crabs, fish and worms. It is also a kleptoparasite, stealing food items from other species of birds. It is a poor swimmer, having only partially webbed feet, and usually stays on land, moving up the beach in front of the rising tide. [7]
It breeds in saltmarshes, its nest being a simple scrape in the ground. The birds are monogamous and each pair occupies a territory. Two or three eggs are laid in May and incubation takes about 22 days. Adults and young birds leave for their winter quarters in October. [7]
The total population of this gull is estimated as being 14,400 individuals [1] but perhaps as low as 7,100–9,600, [4] and seems to be in decline. The IUCN has rated it as "vulnerable". The main threats it faces are the degradation of its habitat as it is very dependent on saltmarshes dominated by Suaeda. In China, Taiwan, South Korea, Japan and elsewhere, saltmarshes are being drained to make way for aquaculture. The introduction of the strong-growing Spartina alterniflora (smooth cord-grass) has also had deleterious effects. The disturbance of adults also results in greater predation on the eggs and chicks. [1]
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.
The common gull is a medium-sized gull that breeds in cool temperate regions of the Palearctic from Iceland and Scotland east to Kamchatka in the Russian Far East. Most common gulls migrate further south in winter, reaching the Mediterranean Sea, the southern Caspian Sea, and the seas around China and Japan; northwest European populations are at least partly resident. The closely related short-billed gull was formerly often included in this species, which was then sometimes known collectively as "mew gull".
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 little tern is a seabird of the family Laridae. It was first described by the German naturalist Peter Simon Pallas in 1764 and given the binomial name Sterna albifrons. It was moved to the genus Sternula when the genus Sterna was restricted to the larger typical terns. The genus name Sternula is a diminutive of Sterna, 'tern', while the specific name albifrons is from Latin albus, 'white', and frons, 'forehead'.
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.
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.
Pallas's gull, also known as the great black-headed gull, is a large bird species. As is the case with many gulls, it has traditionally been placed in the genus Larus. The scientific name is from Ancient Greek. Ichthyaetus is from ikhthus, "fish", and aetos, "eagle".
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 is a small gull. It is usually treated as the only species placed in the genus Xema, though some authors include it with other gulls in a wide view of the genus Larus. It has also been known historically as fork-tailed gull or "xeme". It breeds in colonies on arctic 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 brown-headed gull is a small gull which breeds in the high plateaus of central Asia from Tajikistan to Ordos in Inner Mongolia. It is migratory, wintering on the coasts and large inland lakes of the Indian Subcontinent. As is the case with many gulls, was traditionally placed in the genus Larus.
The grey-headed gull, also known as the gray-hooded gull, is a small species of gull which breeds patchily in South America and Africa south of the Sahara. It is not truly migratory, but is more widespread in winter. This species has occurred as a rare vagrant to North America, Italy and Spain. As is the case with many gulls, it has traditionally been placed in the genus Larus.
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.
The California gull is a medium-sized gull, smaller on average than the herring gull, but larger on average than the ring-billed gull. It lives not just in California, but up and down the entire Western coast of North America, and has breeding ground inland.
The black skimmer is a tern-like seabird, one of three similar bird species in the skimmer genus Rynchops in the gull family Laridae. It breeds in North and South America. Northern populations winter in the warmer waters of the Caribbean and the tropical and subtropical Pacific and Atlantic coasts, but South American populations make only shorter movements in response to annual floods which extend their feeding areas in the river shallows.
The relict gull or Central Asian gull is a medium-sized gull. It was believed to be an eastern race of the Mediterranean gull until 1971 and was traditionally placed in the genus Larus.
Belcher's gull, also known as the band-tailed gull, is a bird in the family Laridae found along the Pacific coast of South America. It formerly included the very similar Olrog's gull as a subspecies, but that bird occurs on the Atlantic coast of South America and is now accepted as Larus atlanticus. Belcher's gull is a medium-sized gull with a blackish mantle, white head and underparts, a black band on the otherwise white tail, and a yellow bill with a red and black tip. Non-breeding adults have a brownish-black head and a white eye-ring. The name of this bird commemorates the British explorer Sir Edward Belcher who performed survey work on the Pacific coast of South America.
The white-eyed gull is a small gull that is endemic to the Red Sea. Its closest relative is the sooty gull. The species is classed as Least Concern by the IUCN; human pressure and oil pollution are deemed the major threats. As is the case with many gulls, it has traditionally been placed in the genus Larus.
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.