Biology:Larus

Short description: Genus of birds

Larus
European herring gull (Larus argentatus)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Charadriiformes
Family:	Laridae
Subfamily:	Larinae
Genus:	Larus Linnaeus, 1758
Type species
Larus marinus Linnaeus, 1758
Species
See list

Larus is a large genus of gulls with worldwide distribution (by far the greatest species diversity is in the Northern Hemisphere).

Many of its species are abundant and well-known birds in their ranges. Until about 2005–2007, most gulls were placed in this genus, but this arrangement is now known to be polyphyletic, leading to the resurrection of the genera Ichthyaetus, Chroicocephalus, Leucophaeus, and Hydrocoloeus (this last had been recognized more often than the other genera) for several species traditionally included in Larus.

They are in general medium to large birds, typically grey or white, often with black markings on their heads or wings. They have stout, longish bills and webbed feet.

The taxonomy of the large gulls in the herring and lesser black-backed complex is very complicated, with different authorities recognising between two and eight species.

Taxonomy

The genus Larus was introduced in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae. The genus name is from Ancient Greek laros (λάῥος) or Latin larus, which appears to have referred to a gull or other large seabird. The type species is the great black-backed gull (Larus marinus).

Species

The genus contains 25 extant species.

Image	Common Name	Scientific name	Distribution
	Pacific gull	L. pacificus	Australia.
	Belcher's gull	L. belcheri	the Pacific coast of South America.
	Olrog's gull	L. atlanticus	Atlantic coast of southern Brazil, Uruguay, and northern Argentina.
	Black-tailed gull	L. crassirostris	coastlines of the East China Sea, Japan, Manchuria and the Kuril Islands, to Alaska and North America
	Heermann's gull	L. heermanni	the United States, Mexico and extreme southwestern British Columbia
	Common gull or mew gull	L. canus	the Palearctic, northern Europe
	Short-billed gull	L. brachyrhynchus	northwestern North America
	Ring-billed gull	L. delawarensis	Canada and the northern United States
	California gull	L. californicus	western North America from the Northwest Territories, Canada south to eastern California and Colorado.
	Great black-backed gull	L. marinus	European and North American coasts and islands of the North Atlantic
	Kelp gull (called southern black-backed gull or karoro in New Zealand)	L. dominicanus	South America, parts of Australia, and New Zealand
	Glaucous-winged gull	L. glaucescens	western coast of Alaska to the coast of Washington, coast of California, Oregon, Baja California, Baja California Sur, and Sonora
	Western gull	L. occidentalis	from British Columbia, Canada to Baja California, Mexico.
	Yellow-footed gull	L. livens	Gulf of California in Mexico
	Glaucous gull	L. hyperboreus	North Atlantic and North Pacific Oceans as far south as the British Isles and northernmost states of the United States, also on the Great Lakes.
	Iceland gull	L. glaucoides	Canada and Greenland
	European herring gull	L. argentatus	shores of Western Europe
	American herring gull	L. smithsonianus	North America from central and southern Alaska to the Great Lakes and north-east coast of the United States from Maine south to North Carolina.
	Yellow-legged gull	L. michahellis	Mediterranean Sea.
	Caspian gull	L. cachinnans	Black and Caspian Seas, extending eastwards across Central Asia to north-west China.
	Vega gull (or East Siberian gull)	L. vegae	northeastern Siberia and winter in Japan, Korea, southern and eastern China, and Taiwan.
	Armenian gull	L. armenicus	the Caucasus and the Middle East
	Slaty-backed gull	L. schistisagus	the north-eastern coast of the Palearctic
	Lesser black-backed gull	L. fuscus	Atlantic coasts of Europe
	White-eyed gull	L. leucophthalmus	Siyal Islands, in the Red Sea

Fossils

Fossils of Larus gulls are known from the Middle Miocene, about 20-15 million years ago; allocation of earlier fossils to this genus is generally rejected. Biogeography of the fossil record suggests that the genus evolved in the northern Atlantic and spread globally during the Pliocene, when species diversity seems to have been highest, as with most seabirds.

• Larus sp. (Middle Miocene of Grund, Austria)
• Larus sp. (Middle Miocene of Romania)
• Larus sp. (Late? Miocene/Early Pliocene of Lee Creek Mine, U.S.) - several species
• Larus elmorei (Middle Pliocene of Bone Valley, southeastern U.S.)
• Larus lacus (Late Pliocene of Pinecrest, southeastern U.S.)
• Larus perpetuus (Pliocene of southeastern U.S.)
• Larus sp. (San Diego Late Pliocene of the southwestern U.S.)
• Larus oregonus (Late Pliocene - Late Pleistocene of the west-central U.S.)
• Larus robustus (Late Pliocene - Late Pleistocene of the west-central U.S.)
• Larus sp. (Late Pleistocene of Lake Manix western U.S.)

"Larus" raemdonckii (Early Oligocene of Belgium) is now at least tentatively believed to belong in the procellariiform genus Puffinus. "L." elegans (Late Oligocene?/Early Miocene of St-Gérand-le-Puy, France) and "L." totanoides (Late Oligocene?/Early Miocene of southeastern France) are now in Laricola, while "L." dolnicensis (Early Miocene of the Czech Republic) was actually a pratincole; it is now placed in Mioglareola.

The Early Miocene "Larus" desnoyersii (southeastern France) and "L." pristinus (John Day Formation, Willow Creek, U.S.) probably do not belong in this genus; the former may be a skua.

Ring species

The Larus gulls interbreed in a ring around the Arctic: 1. L. fuscus graellsii & L. f. intermedius (Westerm European lesser black-backed gulls); 2. L. fuscus fuscus (North East European lesser black-backed gull); 3. L. fuscus heuglini (Heuglin's gull); 4. L. vegae birulai (Birula's gull); 5. L. vegae sensu stricto (Vega gull); 6. L. smithsonianus (American herring gull); 7. L. argentatus (European herring gull)

sensu strictoThe circumpolar group of Larus gull species has often been cited as a classic example of the ring species. The range of these gulls forms a ring around the North Pole. The European herring gull, which lives primarily in Great Britain and Northern Europe, can hybridize with the American herring gull (living in North America), which can also interbreed with the Vega or East Siberian gull, the western subspecies of which, Birula's gull, can hybridize with Heuglin's gull which, in turn, can interbreed with the Siberian lesser black-backed gull (all four of these live across the north of Siberia). The last is the eastern representative of the lesser black-backed gulls back in northwestern Europe, including Great Britain. However, the lesser black-backed gulls and herring gull are sufficiently different that they rarely interbreed; thus, the group of gulls forms a continuum except in Europe, where the two lineages meet. However, a recent genetic study has shown that this example is far more complicated than presented here, and probably does not constitute a true ring species.

See also

• Hybridisation in gulls
• Gull eggs

References

Wikidata ☰ Q1887740 entry