![Flying seagulls at Kiama beach during Christmas, Sydney 2013](https://upload.wikimedia.org/wikipedia/commons/0/0f/Flying_seagulls_at_Kiama_beach_during_Christmas%2C_Sydney_2013.jpg)
Gulls, or colloquially seagulls, are
seabirds
Seabirds (also known as marine birds) are birds that are adaptation, adapted to life within the marine (ocean), marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent ev ...
of the family
Laridae
Laridae is a family of seabirds in the order Charadriiformes that includes the gulls, terns, skimmers and kittiwakes. It includes around 100 species arranged into 22 genera. They are an adaptable group of mostly aerial birds found worldwide. ...
in the suborder
Lari. They are most closely related to the
tern
Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of e ...
s and
skimmers and only distantly related to
auk
An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (a ...
s, and even more distantly to
wader
245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots
Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...
s. Until the 21st century, most gulls were placed in the genus ''
Larus
''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 ...
'', but that arrangement is now considered
polyphyletic
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...
, 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.
Gulls are typically medium to large in size, usually grey or white, often with black markings on the head or wings. They typically have harsh wailing or squawking calls; stout, longish bills; and webbed feet. Most gulls are ground-nesting ]carnivore
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...
s which take live food or scavenge opportunistically, particularly the ''Larus'' species. Live food often includes crustaceans, molluscs, fish and small birds. Gulls have unhinging jaws which allow them to consume large prey. Gulls are typically coastal or inland species, rarely venturing far out to sea, except for the kittiwake
The kittiwakes (genus ''Rissa'') are two closely related seabird species in the gull family Laridae, the black-legged kittiwake (''Rissa tridactyla'') and the red-legged kittiwake (''Rissa brevirostris''). The epithets "black-legged" and "red-l ...
s. The large species take up to four years to attain full adult plumage, but two years is typical for small gulls. Large white-headed gulls are typically long-lived birds, with a maximum age of 49 years recorded for the herring gull Herring gull is a common name for several birds in the genus '' Larus'', all formerly treated as a single species.
Three species are still combined in some taxonomies:
* American herring gull (''Larus smithsonianus'') - North America
* European ...
.
Gulls nest in large, densely packed, noisy colonies. They lay two or three speckled eggs in nests composed of vegetation. The young are precocial
In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...
, born with dark mottled down and mobile upon hatching. Gulls are resourceful, inquisitive, and intelligent, the larger species in particular, demonstrating complex methods of communication and a highly developed social structure. For example, many gull colonies display mobbing
Mobbing, as a sociological term, means bullying of an individual by a group, in any context, such as a family, peer group, school, workplace, neighborhood, community, or online. When it occurs as physical and emotional abuse in the workplace, suc ...
behavior, attacking and harassing predators and other intruders. Certain species have exhibited tool-use behavior, such as the herring gull, using pieces of bread as bait with which to catch goldfish
The goldfish (''Carassius auratus'') is a freshwater fish in the family Cyprinidae of order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the wild have bec ...
, for example. Many species of gulls have learned to coexist successfully with humans and have thrived in human habitats. Others rely on kleptoparasitism
Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when f ...
to get their food. Gulls have been observed preying on live whales, landing on the whale as it surfaces to peck out pieces of flesh.
Description and morphology
Gulls range in size from the little gull
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 ...
, at and , to the great black-backed gull
The great black-backed gull (''Larus marinus'') 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 t ...
, at and . They are generally uniform in shape, with heavy bodies, long wings, and moderately long necks. The tails of all but three species are rounded; the exceptions being Sabine's gull
Sabine's gull ( ) (''Xema sabini'') also known as the fork-tailed gull or xeme, is a small gull. It is the only species placed in the genus ''Xema''. It breeds in colonies on coasts and tundra, laying two or three spotted olive-brown eggs in a gr ...
and swallow-tailed gull
The swallow-tailed gull (''Creagrus furcatus'') is an equatorial seabird in the gull family, Laridae. It is the only species in the genus ''Creagrus'', which derives from the Latin ''Creagra'' and the Greek ''kreourgos'' which means butcher, al ...
s, which have forked tails, and Ross's gull
Ross's gull (''Rhodostethia rosea'') is a small gull, the only species in its genus, although it has been suggested it should be moved to the genus '' Hydrocoloeus'', which otherwise only includes the little gull.
This bird is named after the B ...
, which has a wedge-shaped tail. Gulls have moderately long legs, especially when compared to the similar terns, with fully webbed feet. The bill is generally heavy and slightly hooked, with the larger species having stouter bills than the smaller species. The bill colour is often yellow with a red spot for the larger white-headed species and red, dark red or black in the smaller species.
The gulls are generalist feeders. Indeed, they are the least specialised of all the seabirds, and their morphology allows for equal adeptness in swimming, flying, and walking. They are more adept walking on land than most other seabirds, and the smaller gulls tend to be more manoeuvrable while walking. The walking gait of gulls includes a slight side to side motion, something that can be exaggerated in breeding displays. In the air, they are able to hover and they are also able to take off quickly with little space.
The general pattern of plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
in adult gulls is a white body with a darker mantle; the extent to which the mantle is darker varies from pale grey to black. A few species vary in this, the ivory gull is entirely white, and some like the lava gull
The lava gull (''Leucophaeus fuliginosus''), also known as the dusky gull, is a medium-sized gull and a member of the "hooded gull" group. It is most closely related to the Laughing gull and Franklin's gull and is the rarest gull in the world. It ...
and Heermann's gull
Heermann's gull (''Larus heermanni'') is a gull resident in the United States, Mexico and extreme southwestern British Columbia, nearly all nesting on Isla Rasa in the Gulf of California. They are usually found near shores or well out to sea, very ...
have partly or entirely grey bodies. The wingtips of most species are black, which improves their resistance to wear and tear, usually with a diagnostic pattern of white markings. The head of a gull may be covered by a dark hood or be entirely white. The plumage of the head varies by breeding season; in nonbreeding dark-hooded gulls, the hood is lost, sometimes leaving a single spot behind the eye, and in white-headed gulls, nonbreeding heads may have streaking.
Distribution and habitat
The gulls have a worldwide cosmopolitan distribution
In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...
. They breed on every continent, including the margins of Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...
, and are found in the high Arctic as well. They are less common on tropical islands, although a few species do live on islands such as the Galapagos and New Caledonia
)
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, image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg
, map_alt = Location of New Caledonia
, map_caption = Location of New Caledonia
, mapsize = 290px
, subdivision_type = Sovereign st ...
. Many species breed in coastal colonies, with a preference for islands, and one species, the grey gull
The grey gull, also known as garuma gull (''Leucophaeus modestus'') is a medium-sized gull native to South America. Unusual among gulls, it breeds inland in the extremely dry Atacama Desert in northern Chile, although it is present as a non-bree ...
, breeds in the interior of dry deserts far from water. Considerable variety exists in the family and species may breed and feed in marine, freshwater, or terrestrial habitats.
Most gull species are migratory, with birds moving to warmer habitats during the winter, but the extent to which they migrate varies by species. Some migrate long distances, like Franklin's gull
Franklin's gull (''Leucophaeus pipixcan'') is a small (length 12.6–14.2 in, 32–36 cm) gull. The genus name ''Leucophaeus'' is from Ancient Greek ''leukos'', "white", and ''phaios'', "dusky". The specific ''pipixcan'' is a Nahuatl name f ...
, which migrates from Canada to wintering grounds in the south of South America. Other species move much shorter distances and may simply disperse along the coasts near their breeding sites.
A big influence on non-breeding gull distribution are food patches. Human fisheries especially have an impact since they often provide an abundant and predictable food resource. Looking at two species of gulls dependent on human fisheries, Audouin (''Ichthyaetus audouinii'') and black-backed gulls (''Larus fuscus)'', their breeding distributions (especially the black-backed gull) was heavily impacted by human fishing discards and fishing ports.
Looking further at environmental drivers that structure bird habitat and distribution are human and climate impacts. Looking at waterbird distribution in wetlands, changes in salinity, water depth, water body isolation and hydroperiod altered bird community structure in both a species and guild specific way. Gulls in particular had high associations with salinity levels, being the main environmental predictor for waterbird assemblage.
Behaviour
Diet and feeding
Charadriiform birds drink salt water, as well as fresh water, as they possess exocrine glands located in supraorbital grooves of the skull by which salt can be excreted through the nostrils to assist the kidneys in maintaining electrolyte balance.
Gulls are highly adaptable feeders that opportunistically take a wide range of prey. The food taken by gulls includes fish and marine and freshwater invertebrates, both alive and already dead, terrestrial arthropods
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
and invertebrates such as insects and earthworms, rodents, eggs, carrion, offal
Offal (), also called variety meats, pluck or organ meats, is the organs of a butchered animal. The word does not refer to a particular list of edible organs, which varies by culture and region, but usually excludes muscle. Offal may also refe ...
, reptiles, amphibians, plant items such as seeds and fruit, human refuse, and even other birds. No gull species is a single-prey specialist, and no gull species forages using only a single method. The type of food depends on circumstances, and terrestrial prey such as seeds, fruit, and earthworms are more common during the breeding season while marine prey is more common in the nonbreeding season when birds spend more time on large bodies of water.
In addition to taking a wide range of prey, gulls display great versatility in how they obtain prey. Prey can be obtained in the air, on water, or on land. In the air, a number of hooded species are able to hawk insects on the wing; larger species perform this feat more rarely. Gulls on the wing also snatch items both off water and off the ground, and over water they also plunge-dive to catch prey. Again, smaller species are more manoeuvrable and better able to hover-dip fish from the air. Dipping is also common when birds are sitting on the water, and gulls may swim in tight circles or foot paddle to bring marine invertebrates up to the surface. Food is also obtained by searching the ground, often on the shore among sand, mud or rocks. Larger gulls tend to do more feeding in this way. In shallow water gulls may also engage in foot paddling. One method of obtaining prey involves dropping heavy shells of clams and mussels onto hard surfaces. Gulls may fly some distance to find a suitable surface on which to drop shells, and apparently a learned component to the task exists, as older birds are more successful than younger ones. While overall feeding success is a function of age, the diversity in both prey and feeding methods is not. The time taken to learn foraging skills may explain the delayed maturation in gulls.
Gulls have only a limited ability to dive below the water to feed on deeper prey. To obtain prey from deeper down, many species of gulls feed in association with other animals, where marine hunters drive prey to the surface when hunting. Examples of such associations include four species of gulls feeding around plumes of mud brought to the surface by feeding grey whale
The gray whale (''Eschrichtius robustus''), also known as the grey whale,Britannica Micro.: v. IV, p. 693. gray back whale, Pacific gray whale, Korean gray whale, or California gray whale, is a baleen whale that migrates between feeding and bree ...
s, and also between orca
The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus '' Orcinus'' and is recognizable by its black-and-white ...
s (largest dolphin species) and kelp gull
The kelp gull (''Larus dominicanus''), also known as the Dominican gull, is a gull that breeds on coasts and islands through much of the Southern Hemisphere. The nominate ''L. d. dominicanus'' is the subspecies found around South America, part ...
s (and other seabirds).
Looking at the effect of humans on gull diet, overfishing of target prey such as sardines have caused a shift in diet and behavior. Analysis of yellow-legged gull's (''Larus michahellis
The yellow-legged gull (''Larus michahellis'') 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 Casp ...
)'' pellets off the northwest coast of Spain revealed a shift from a sardine to crustacean-based diet. This shift was linked to higher fishing efficiency and thus overall fish stock depletion. Lastly, closure of nearby open-air landfills limited food availability for the gulls, furthering creating a stress on their shift in diet. Between the years of 1974–1994, yellow-legged gull populations in Berlenga Island, Portugal, increased from 2600 to 44,698 individuals. Analyzing both adult and chick remains, researchers found a mixture of both natural prey and human refuse. The gulls relied substantially on the Henslow's swimming crab (''Polybius henslowii
''Polybius henslowii'' is a species of crab, the only species in the genus ''Polybius''. It is a capable swimmer and feeds in open water in the north-east Atlantic Ocean and western Mediterranean Sea.
Description
The carapace of ''P. henslo ...
''). Yet, in times when local prey availability is low, the gulls shift to human-related food. These temporal shifts from a marine to terrestrial prey highlight the resilience adult gulls have and their ability to keep chick condition consistent. Human disturbance has also shown to have an effect on gull breeding, in which hatching failure is directly proportional to the amount of disturbance in a given plot. Certain gull breeds have been known to feast on the eye balls of baby seals, and directly pilfer milk from the elephant seal
Elephant seals are very large, oceangoing earless seals in the genus ''Mirounga''. Both species, the northern elephant seal (''M. angustirostris'') and the southern elephant seal (''M. leonina''), were hunted to the brink of extinction for oi ...
's teat.
File:Seagull eating starfish.jpg, 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 gul ...
eating a starfish
File:Gull attacking coot.jpg, Gull attacking a coot – this gull is probably going after the bread or other food item in the bill of this American coot
The American coot (''Fulica americana''), also known as a mud hen or pouldeau, is a bird of the family Rallidae. Though commonly mistaken for ducks, American coots are only distantly related to ducks, belonging to a separate order. Unlike the w ...
, though great black-backed gull
The great black-backed gull (''Larus marinus'') 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 t ...
s are known to kill and eat coots
Coots are medium-sized water birds that are members of the rail family, Rallidae. They constitute the genus ''Fulica'', the name being the Latin term for "coot". Coots have predominantly black plumage, and—unlike many rails—they are usually ...
File:Flying ducks.jpg, Lesser black-backed gulls in a feeding frenzy
In ecology, a feeding frenzy occurs when predators are overwhelmed by the amount of prey available. The term is also used as an idiom in the English language.
Examples in nature
For example, a large school of fish can cause nearby sharks, such a ...
File:Seagull taking off the Sandy Hook shore.jpg, Juvenile ring-billed gull
The ring-billed gull (''Larus delawarensis'') is a medium-sized gull. The genus name is from Latin ''Larus'' which appears to have referred to a gull or other large seabird. The specific ''delawarensis'' refers to the Delaware River.
Description ...
at Sandy Hook, New Jersey
Sandy Hook is a barrier spit in Middletown Township, Monmouth County, New Jersey, United States.
The barrier spit, approximately in length and varying from wide, is located at the north end of the Jersey Shore. It encloses the southern ...
File:Birdsniper.jpg, European herring gull
The European herring gull (''Larus argentatus'') is a large gull, up to 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 ...
stealing food from a man's hand
Breeding
Gulls are monogamous and colonial
Colonial or The Colonial may refer to:
* Colonial, of, relating to, or characteristic of a colony or colony (biology)
Architecture
* American colonial architecture
* French Colonial
* Spanish Colonial architecture
Automobiles
* Colonial (1920 au ...
breeders that display mate fidelity that usually lasts for the life of the pair. Divorce of mated pairs does occur, but it apparently has a social cost that persists for a number of years after the break-up. Gulls also display high levels of site fidelity, returning to the same colony after breeding there once and even usually breeding in the same location within that colony. Colonies can vary from just a few pairs to over a hundred thousand pairs, and may be exclusive to that gull species or shared with other seabird species. A few species nest singly, and single pairs of band-tailed gulls may breed in colonies of other birds. Within colonies, gull pairs are territorial
A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal.
In international politics, a territory is usually either the total area from which a state may extract power resources or a ...
, defending an area of varying size around the nesting site from others of their species. This area can be as large as a 5-m radius around the nest in the herring gull Herring gull is a common name for several birds in the genus '' Larus'', all formerly treated as a single species.
Three species are still combined in some taxonomies:
* American herring gull (''Larus smithsonianus'') - North America
* European ...
to just a tiny area of cliff ledge in the kittiwake
The kittiwakes (genus ''Rissa'') are two closely related seabird species in the gull family Laridae, the black-legged kittiwake (''Rissa tridactyla'') and the red-legged kittiwake (''Rissa brevirostris''). The epithets "black-legged" and "red-l ...
s.
Most gulls breed once a year and have predictable breeding seasons lasting for three to five months. Gulls begin to assemble around the colony for a few weeks prior to occupying the colony. Existing pairs re-establish their pair-bonds, and unpaired birds begin courting. Birds then move back into their territories and new males establish new territories and attempt to court females. Gulls defend their territories from rivals of both sexes through calls and aerial attacks.
Nest building is also part of the pair-bonding. Gull nests are usually mats of herbaceous matter with a central nest cup. Nests are usually built on the ground, but a few species build nests on cliffs, including the kittiwakes, which almost always nest in such habitats, and in some cases in trees, and high places like Bonaparte's gull
Bonaparte's gull (''Chroicocephalus philadelphia'') is a member of the gull family Laridae found mainly in northern North America. At in length, it is one of the smallest species of gull. Its plumage is mainly white with grey upperparts. During ...
s. Species that nest in marshes must construct a nesting platform to keep the nest dry, particularly in species that nest in tidal marshes. Both sexes gather nesting material and build the nest, but the division of labour is not always exactly equal. In coastal towns, many gulls nest on rooftops and can be observed by nearby human residents.
Clutch size
__NOTOC__
A clutch of egg (biology), eggs is the group of eggs produced by birds, amphibians, or reptiles, often at a single time, particularly those laid in a nest.
In birds, destruction of a clutch by predators (or removal by humans, for exam ...
is typically three eggs, although it is two in some of the smaller species and only one egg for the swallow-tailed gull. Within colonies, birds synchronise their laying, with synchronisation being higher in larger colonies, although after a certain point, this levels off. The eggs of gulls are usually dark tan to brown or dark olive with dark splotches and scrawl markings, and are well camouflaged. Both sexes incubate the eggs, with incubation bouts lasting between one and four hours during the day and one parent incubating through the night. Research on various bird species including the gull suggests that females form pair bonds with other females to obtain alloparental care
Alloparenting (also referred to as alloparental care) is a term used to classify any form of parental care provided by an individual towards young that aren't its own direct offspring. These are often referred to as "non-descendant" young, even th ...
for their dependent offspring, a behavior seen in other animal species, like the elephants, wolves, and the fathead minnow
Fathead minnow (''Pimephales promelas''), also known as fathead or tuffy, is a species of temperate freshwater fish belonging to the genus ''Pimephales'' of the cyprinid family. The natural geographic range extends throughout much of North Amer ...
.
Incubation lasts between 22 and 26 days, and begins after laying the first egg, although it is discontinuous until the second egg is laid. This means the first two chicks are born close together, and the third chick some time later. Young chicks are brooded by their parents for about one or two weeks, and often at least one parent remains with them, until they fledge
Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight.
This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...
, to guard them. Both parents feed the chicks, although early on in the rearing period, the male does most of the feeding and the female most of the brooding and guarding.
Taxonomy
The family Laridae was introduced (as Laridia) by the French polymath
A polymath ( el, πολυμαθής, , "having learned much"; la, homo universalis, "universal human") is an individual whose knowledge spans a substantial number of subjects, known to draw on complex bodies of knowledge to solve specific pro ...
Constantine Samuel Rafinesque
Constantine Samuel Rafinesque-Schmaltz (; October 22, 1783September 18, 1840) was a French 19th-century polymath born near Constantinople in the Ottoman Empire and self-educated in France. He traveled as a young man in the United States, ultimat ...
in 1815. The taxonomy
Taxonomy is the practice and science of categorization or classification.
A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
of gulls is confused by their widespread distribution zones of hybridization leading to geneflow
In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent a ...
. Some have traditionally been considered ring species
In biology, a ring species is a connected series of neighbouring populations, each of which interbreeds with closely sited related populations, but for which there exist at least two "end" populations in the series, which are too distantly relate ...
, but recent evidence suggests that this assumption is questionable. Until recently, most gulls were placed in the genus ''Larus'', but this arrangement is now known to be polyphyletic
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...
, 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''.Pons J.M., Hassanin, A., and Crochet P.A.(2005). ''Phylogenetic relationsh ...
'', ''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 ...
'', ''Leucophaeus
''Leucophaeus'' is a small genus of medium-sized New World gulls, most of which are dark in plumage, usually with white crescents above and below the eyes. They were placed in the genus ''Larus'' until recently. The genus name ''Leucophaeus'' is ...
'', '' Saundersilarus'', and '' Hydrocoloeus''. Some English names refer to species complexes within the group:
* Large white-headed gull is used to describe the 18 or so herring gull-like species from California gull
The California gull (''Larus californicus'') is a medium-sized gull, smaller on average than the herring gull but larger on average than the ring-billed gull, though it may overlap in size greatly with both.
Description
Adults are similar in ap ...
to lesser black-backed gull
The lesser black-backed gull (''Larus fuscus'') is a large gull that breeds on the Atlantic coasts of Europe. It is migratory, wintering from the British Isles south to West Africa. It has increased dramatically in North America, most common alo ...
in the taxonomic list below.
* White-winged gull is used to describe the four pale-winged, high Arctic-breeding taxa within the former group; these are Iceland gull, glaucous gull, Thayer's gull
Thayer's gull (''Larus glaucoides thayeri'') is a subspecies of the Iceland gull. It is a large gull native to North America that breeds in the Arctic islands of Canada and winters primarily on the Pacific coast, from southern Alaska to the Gulf ...
, and Kumlien's gull
Kumlien's gull (''Larus glaucoides kumlieni'') is a subspecies of the Iceland gull. It is a large gull which breeds in the Arctic regions of Canada. It is migratory, wintering from Labrador south to New England and west across the Great Lakes. ...
.
In common usage, members of various gull species are often referred to as sea gulls or seagulls; however, "seagull" is a layperson's term that is not used by most ornithologists and biologists. This name is used informally to refer to a common local species or all gulls in general, and has no fixed taxonomic meaning. In common usage, gull-like seabirds that are not technically gulls (e.g. albatrosses, fulmar
The fulmars are tubenosed seabirds of the family Procellariidae. The family consists of two extant species and two extinct fossil species from the Miocene.
Fulmars superficially resemble gulls, but are readily distinguished by their flight on ...
s, tern
Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of e ...
s, and 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 ...
s) may also be referred to as seagulls by the layperson.
The American Ornithologists' Union
The American Ornithological Society (AOS) is an ornithological organization based in the United States. The society was formed in October 2016 by the merger of the American Ornithologists' Union (AOU) and the Cooper Ornithological Society. Its m ...
combines the Sternidae, Stercorariidae, and Rhynchopidae as subfamilies in the family Laridae, but recent research indicates this is incorrect.
A molecular phylogenetic study published in 2022 found the following relationships between the genera. Some authorities place the Saunders's gull in its own genus ''Saundersilarus''.
List of species
This is a list of the 54 gull species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
, presented in taxonomic sequence
Taxonomic sequence (also known as systematic, phyletic or taxonomic order) is a sequence followed in listing of taxa which aids ease of use and roughly reflects the evolutionary relationships among the taxa. Taxonomic sequences can exist for taxa ...
.
Evolutionary history
The Laridae are known from not-yet-published 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 ...
evidence since the Early Oligocene
The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene Epoch/ Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian ...
, some 30–33 million years ago. Three gull-like species were described by Alphonse Milne-Edwards
Alphonse Milne-Edwards (Paris, 13 October 1835 – Paris, 21 April 1900) was a French mammalogist, ornithologist, and carcinologist. He was English in origin, the son of Henri Milne-Edwards and grandson of Bryan Edwards, a Jamaican planter who se ...
from the early Miocene of Saint-Gérand-le-Puy, France. A fossil gull from the Middle to Late Miocene
The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...
of Cherry County, Nebraska
Cherry County is a county located in the U.S. state of Nebraska. As of the 2010 United States Census, the population was 5,713. Its county seat is Valentine. The county was named for Lt. Samuel A. Cherry, an Army officer who was stationed ...
, USA
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
, is placed in the prehistoric genus '' Gaviota''; apart from this and the undescribed Early Oligocene fossil, all prehistoric species were tentatively assigned to the modern genus ''Larus''. Among those of them that have been confirmed as gulls, Milne-Edwards' ''"Larus" elegans'' and ''"L." totanoides'' from the Late Oligocene/Early Miocene
The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages.
The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...
of southeast France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
have since been separated in '' Laricola''.
References
Further reading
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External links
Rudy's Gull-index
Pictures of less well-known plumages of large gulls
Gull videos
on the Internet Bird Collection
{{Authority control
Articles containing video clips
Bird common names
Laridae
Seabirds