genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
gull
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 only distantly related to auks, and even more distantly to waders. Until the 21st century, m ...
s with worldwide distribution (by far the greatest species diversity is in the
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
).
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
''Ichthyaetus'' is a genus of gulls. The genus name is from Ancient Greek ''ikhthus'', "fish", and ''aetos'', "eagle". They were previously included in the genus ''Larus
''Larus'' is a large genus of gulls with worldwide distribution (by fa ...
'', ''
Chroicocephalus
''Chroicocephalus'' is a genus of medium to relatively small gulls which were included in the genus ''Larus'' until recently. Some authorities also include the Saunders's gull in ''Chroicocephalus''. The genus name '' Chroicocephalus'' is from A ...
Hydrocoloeus
The little gull (''Hydrocoloeus minutus'' or ''Larus minutus''), is a small gull that breeds in northern Europe and across the Palearctic. The genus name ''Hydrocoloeus'' is from Ancient Greek , "water", and , a sort of web-footed bird. The speci ...
'' (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
bill
Bill(s) may refer to:
Common meanings
* Banknote, paper cash (especially in the United States)
* Bill (law), a proposed law put before a legislature
* Invoice, commercial document issued by a seller to a buyer
* Bill, a bird or animal's beak
Plac ...
s and webbed feet.
The taxonomy of the large gulls in the
herring
Herring are forage fish, mostly belonging to the family of Clupeidae.
Herring often move in large schools around fishing banks and near the coast, found particularly in shallow, temperate waters of the North Pacific and North Atlantic Oceans, i ...
and lesser black-backed complex is very complicated, with different authorities recognising between two and eight species.
Taxonomy
The
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''Larus'' was introduced in 1758 by the Swedish naturalist
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
Systema Naturae
' (originally in Latin written ' with the ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial nomen ...
''. The genus name is from
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
''laros'' (λάῥος) or
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''larus'', which appears to have referred to a gull or other large seabird. The
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
s of ''Larus'' gulls are known from the
Middle Miocene
The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene.
The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...
, about 20-15 million years ago; allocation of earlier fossils to this genus is generally rejected.
Biogeography
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...
of the fossil record suggests that the genus evolved in the northern
Atlantic
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
and spread globally during the
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Lee Creek Mine, U.S.) - several species
*''Larus elmorei'' (Early/Middle Pliocene of Bone Valley, southeastern U.S.)
*''Larus lacus'' ( Late Pliocene of Pinecrest, southeastern U.S.)
*''Larus perpetuus'' (Late Pliocene of Pinecrest, 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
Procellariiformes is an order of seabirds that comprises four families: the albatrosses, the petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still called tubenoses in English, procellariiforms are oft ...
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
The pratincoles or greywaders are a group of birds which together with the coursers make up the family Glareolidae. They have short legs, very long pointed wings and long forked tails.
Description
Their most unusual feature for birds classed as ...
; 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
The skuas are a group of predatory seabirds with seven species forming the genus ''Stercorarius'', the only genus in the family Stercorariidae. The three smaller skuas, the long-tailed skua, the Arctic skua, and the pomarine skua are called jae ...
.(Olson, 1985).
Ring species
The 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 North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface. It is called the True North Pole to distinguish from the Mag ...
Great Britain
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...
and
Northern Europe
The northern region of Europe has several definitions. A restrictive definition may describe Northern Europe as being roughly north of the southern coast of the Baltic Sea, which is about 54th parallel north, 54°N, or may be based on other g ...
, can
hybridize
Hybridization (or hybridisation) may refer to:
*Hybridization (biology), the process of combining different varieties of organisms to create a hybrid
*Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals
*Nu ...
with the
American herring gull
The American herring gull or Smithsonian gull (''Larus smithsonianus'' or ''Larus argentatus smithsonianus'') is a large gull that breeds in North America, where it is treated by the American Ornithological Society as a subspecies of herring gull ...
(living in North America), which can also interbreed with the
Vega
Vega is the brightest star in the northern constellation of Lyra. It has the Bayer designation α Lyrae, which is Latinised to Alpha Lyrae and abbreviated Alpha Lyr or α Lyr. This star is relatively close at only from the Sun, an ...
or East Siberian gull, the western subspecies of which, Birula's gull, can hybridize with
Heuglin's gull
Heuglin's gull (''Larus fuscus heuglini'') or the Siberian gull, is a seabird in the genus ''Larus''. Taxonomy
It is sometimes considered as a separate species (''Larus heuglini'') but is now usually treated as a subspecies of the lesser black- ...
which, in turn, can interbreed with the Siberian lesser black-backed gull (all four of these live across the north of
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
). 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.Supplemental material: Electronic appendices /ref>
See also
*
Hybridisation in gulls
Hybridisation in gulls occurs quite frequently, although to varying degrees depending on the species involved.
Hybrid large white-headed gulls
* Herring gulls and lesser black-backed gulls interbreed to a limited degree where their ranges overlap, ...