Short-billed gull | |
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Adult short-billed gull, Anchorage Coastal Wildlife Refuge, Alaska | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Charadriiformes |
Family: | Laridae |
Genus: | Larus |
Species: | L. brachyrhynchus |
Binomial name | |
Larus brachyrhynchus Richardson, 1831 | |
The short-billed gull (Larus brachyrhynchus) is a medium-sized species of gull that breeds in northwestern North America. In North America it was previously known as the mew gull, when it was considered conspecific with the palearctic common gull (Larus canus). Most authorities, including the American Ornithological Society in 2021, have split the two populations as distinct species. [1]
The species was first described by Scottish naturalist John Richardson in 1831 as the 'short-billed mew gull', Larus brachyrhynchus. [2]
Though some authorities, including the American Ornithologist's Union from 1931 onwards, have long considered brachyrhynchus to be a subspecies of the common gull, others have recognized the two as distinct species. [3] In 2021, the American Ornithological Society agreed to split the short-billed gull as a distinct species based on differences in genetics, plumage, morphology and vocalizations. [1] Though 'mew gull' has been used as name for the species in North America, the name short-billed gull was chosen due to the usage of "mew gull" in recent literature to denote all forms of L. canus and the fact that short-billed gull was previously used in older AOS checklists since 1886. [4]
The short-billed gull is a small gull with a length 40–45 cm (16–18 in) and a wingspan 100–120 cm (39–47 in). It is smaller than other gulls in the Common gull complex, with a shorter bill and longer wings. [5] Its wings appear long and narrow in flight relative to its short body. In breeding plumage, adults have a white head, pale eyes surrounded by a red orbital skin, yellow legs and bill with not markings. In winter, the head is marked with brown mottling, the eye orbital skin becomes greyish and the bill becomes duller with a faint dark marking. In flight, the two outermost primary feathers (p9 and p10) have conspicuous white spots or "mirrors". Between p5 and p8, the primaries have white "tongue tips" which form a 'string of pearls' transitioning to the broad white trailing edge. p4 usually has a black markings in many birds. In comparison, common gulls have a larger bill and shorter wings. The wingtips of common gulls have more extensive black wingtips with smaller mirrors on p9-10, a narrower trailing edge, and typically lack black markings on p4 as well as the white tongue tip on p8. [5]
Short-billed gulls take 3 years to attain breeding plumage. Juveniles are brownish overall with dark brown wingtips. They appear darker and more smudged on the head and neck, compared to the paler and finely-marked common gull, which more closely resembles Ring-billed gull at this stage. Many first-year birds retain juvenile plumage through the winter, but some grow greyish saddle feathers intermixed with juvenile feathers. The bill becomes pink at the base with a black tip by the first winter. Second-year birds resemble adults but may have brown wing covert feathers and black markings on the tertials, lacking white spots on the wingtips except the p10 mirror. Third-year birds are similar to adults but may have dark markings on primary coverts, secondaries, underwing and tail, with more extensive black on the wingtips. [5]
The short-billed gull breeds in colonies along coastal areas and inland wetlands, mainly in Alaska and Northwest Canada. Most birds winter along the Pacific coast down to the Sacramento Valley, and less frequently to Baja California, the Northern Rockies and Ontario. [5] It is a very rare visitor to eastern North America and a vagrant to east Asia. There is one recent record of a short-billed gull in Europe, on the Azores in 2003. [6]
The common gull or sea mew is a medium-sized gull that breeds in the Palearctic, northern Europe. 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 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, which follows the American Ornithologists' Union.
The European herring gull is a large gull, up to 66 cm (26 in) long. One of the best-known of all gulls along the shores of Western Europe, it was once abundant. It breeds across Northern Europe, Western Europe, Central Europe, Eastern Europe, Scandinavia, and the Baltic states. Some European herring gulls, especially those resident in colder areas, migrate further south in winter, but many are permanent residents, e.g. 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 glaucous-winged gull is a large, white-headed gull. The genus name is from Latin Larus which appears to have referred to a gull or other large seabird. The specific glaucescens is New Latin for "glaucous" from the Ancient Greek, glaukos, denoting the grey color of its wings.
The white-eyed gull is a small gull that is endemic to the Red Sea. Its closest relative is the sooty gull. It is one of the world's rarest gulls, with a population of 4,000 – 6,500 pairs. The species is classed as Near Threatened 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 American herring gull or Smithsonian gull is a large gull that breeds in North America, where it is treated by the American Ornithologists' Union as a subspecies of herring gull.