Short-billed gull

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Short-billed gull
Larus brachyrhynchus, Potter's Marsh, Anchorage, Alaska.jpg
Adult short-billed gull, Anchorage Coastal Wildlife Refuge, Alaska
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Laridae
Genus: Larus
Species:
L. brachyrhynchus
Binomial name
Larus brachyrhynchus
Richardson, 1831
Larus brachyrhynchus map.svg

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]

Contents

Taxonomy

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]

Description

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 no markings. In winter, the head is marked with brown mottling, the eye orbital skin becomes grayish 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]

First-winter short-billed gull Mew Gull (American) - Flickr - Fyn Kynd.jpg
First-winter short-billed gull

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 grayish 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]

Subadult (third-year) short-billed gull in flight. Note the white tongue tips forming a "string of pearls" between primaries 5 and 8. Mew Gull, Lake Spenard, Anchorage, Alaska.jpg
Subadult (third-year) short-billed gull in flight. Note the white tongue tips forming a "string of pearls" between primaries 5 and 8.

Distribution

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]

Related Research Articles

<span class="mw-page-title-main">Common gull</span> Species of bird

The common gull is a gull that breeds in cool temperate regions of the Palearctic. 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 known collectively as "mew gull".

<span class="mw-page-title-main">European herring gull</span> Species of bird

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.

<span class="mw-page-title-main">Great black-backed gull</span> Species of bird

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.

<span class="mw-page-title-main">Slaty-backed gull</span> Species of bird

The slaty-backed gull is a large, white-headed gull that breeds on the north-eastern coast of the Palearctic, but travels widely during nonbreeding seasons. It is similar in appearance to the western gull and the glaucous-winged gull. Another alternate name is Pacific gull, though it also applies to a Southern Hemisphere species, L. pacificus.

<span class="mw-page-title-main">Glaucous-winged gull</span> Species of bird

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 Neo-Latin for "glaucous" from the Ancient Greek, glaukos, denoting the grey color of its wings.

<i>Gulls of Europe, Asia and North America</i> 2004 book by Klaus Malling Olsen and Hans Larsson

Gulls of Europe, Asia and North America by Klaus Malling Olsen and Hans Larsson is a volume in the Helm Identification Guides series of bird identification books.

<span class="mw-page-title-main">Thayer's gull</span> Subspecies of bird

Thayer's gull is a subspecies of the Iceland gull. It is a large gull native to North America.

<span class="mw-page-title-main">American herring gull</span> Species of bird

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.

References

  1. 1 2 Chesser, R Terry; Billerman, Shawn M; Burns, Kevin J; Cicero, Carla; Dunn, Jon L; Hernández-Baños, Blanca E; Kratter, Andrew W; Lovette, Irby J; Mason, Nicholas A; Rasmussen, Pamela C; Remsen, J V (2021-06-29). "Sixty-second Supplement to the American Ornithological Society's Check-list of North American Birds". Ornithology. 138 (3): ukab037. doi: 10.1093/ornithology/ukab037 . ISSN   0004-8038.
  2. Swainson, William; Richardson, Sir John (1831). The Birds. John Murray.
  3. Olsen, Klaus Malling (2004). Gulls of Europe, Asia and North America. Hans Larsson. London: Christopher Helm. ISBN   0-7136-7087-8. OCLC   57006518.
  4. Rasmussen, Pamela C. (10 November 2020). "Split Mew Gull Larus canus brachyrhynchus and rename as Short-billed Gull". AOS Classification Committee – North and Middle America. Proposal Set 2021-A: 187–188.
  5. 1 2 3 4 Olsen, Klaus Malling (2018). Gulls of the world : a photographic guide. Princeton, New Jersey. ISBN   978-0-691-18059-5. OCLC   1005861102.{{cite book}}: CS1 maint: location missing publisher (link)
  6. Alfrey, P.; Ahmad, M. (2007). "Short-billed Gull on Terceira, Azores, in February–March 2003 and identification of the 'Mew Gull complex'". Dutch Birding . 29 (4): 201–212.