Gull
Encyclopedia
Gulls are birds in the family
Laridae. They are most closely related to the tern
s (family Sternidae) and only distantly related to auk
s, skimmer
s, and more distantly to the wader
s. Until the twenty-first century most gulls were placed in the genus
Larus
, but this arrangement is now known to be polyphyletic
, leading to the resurrection of several genera
.
Gulls are typically medium to large birds, usually grey or white, often with black markings on the head or wings. They typically have harsh wailing or squawking calls, stout, longish bill
s, and webbed feet. Most gulls, particularly Larus species, are ground-nesting carnivore
s, which will take live food or scavenge
opportunistically. Live food often includes crab
s and small fish
. Gulls have prophylactic unhinging jaws which allow them to consume large prey. Apart from the kittiwake
s, gulls are typically coastal or inland species, rarely venturing far out to sea 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.
Gulls nest in large, densely packed noisy colonies
. They lay two to three speckled eggs
in nests
composed of vegetation. The young are precocial
, being born with dark mottled down
, and mobile upon hatching.
Gulls—the larger species in particular—are resourceful, inquisitive and intelligent birds, demonstrating complex methods of communication and a highly developed social structure. For example, many gull colonies display mobbing behaviour, attacking and harassing would-be predators and other intruders. Certain species (e.g. the Herring Gull
) have exhibited tool use behaviour
, using pieces of bread as bait
with which to catch goldfish
, for example. Many species of gull have learned to coexist successfully with humans and have thrived in human habitats
. Others rely on kleptoparasitism
to get their food. Gulls have been observed preying on live whale
s, landing on the whale as it surfaces to peck out pieces of flesh.
Gull species range in size from the Little Gull
, at 120 g (4.2 oz) and 29 cm (11.5 inches), to the Great Black-backed Gull
, at 1.75 kg (3.8 lbs) and 76 cm (30 inches). They are generally uniform in shape, with heavy bodies, long wings, moderately long necks . The tails of all but three species are rounded; the exceptions being the Sabine's Gull
and Swallow-tailed Gull
s, which have forked tails, and the Ross's Gull
, which has a wedge-shaped tail. Gulls have moderately long legs (certainly longer than the 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
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
and Heermann's Gull
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 makings. The head of gulls may be covered by a dark hood or be entirely white. The plumage of the head varies by breeding season; in non-breeding dark-hooded gulls the hood is lost, sometimes leaving a single spot behind the eye, and in white-headed gulls non-breeding heads may have streaking.
. They breed on every continent, including the margins of Antarctica, 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
. Many species breed in costal colonies, with a preference for islands, and one species, the Grey Gull
, breeds in the interior of dry deserts far from water. There is considerable variety 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 species migrate long distances, like the Franklin's Gull
, 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 costs near their breeding sites.
In addition to taking a wide range prey items 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 will also snatch items both off water and off the ground, and over water they will 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. A unique method of obtaining prey to gulls involves dropping heavy shells of clams and mussels onto hard surfaces. Gulls may fly some distance in order to find a suitable surface on which to drop shells, and there is apparently a learnt component to the task 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. It has been suggested that the time taken to learn foraging skills explains the delayed maturation in gulls.
Gulls have only a limited ability to dive below the water in order to feed on deeper prey. In order to obtain prey from deeper down many species of gull feed in association with other animals, where marine hunters drive prey to the surface when hunting. Examples of such associations include four species of gull feeding around plumes of mud brought to the surface by feeding Grey Whales, and also between Orca
s and Kelp Gull
s (and other seabirds).
and colonial 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 cost that persists for a number of years after the break up, and is thought to be selected against. 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
, 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
to just a tiny area of cliff ledge in the kittiwake
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, like Bonaparte's Gull
s. Species that nest in marshes must construct a nesting platform in order 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 isn't always exactly equal.
Clutch size
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 will synchronise their laying, with synchronisation being higher in larger colonies, although after a certain level 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.
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 are often at least one parent will remain with them until they fledge
in order 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.
of gulls is confused by their widespread distribution zones of hybridization leading to geneflow. Some have traditionally been considered ring species
, 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, leading to the resurrection of the genera Ichthyaetus
, Chroicocephalus
, Leucophaeus
, Saundersilarus and Hydrocoloeus. Some English names refer to species complexes within the group:
Hybridisation between species of gull occurs quite frequently, although to varying degrees depending on the species involved (see Hybridisation in gulls
). The taxonomy of the large white-headed gulls is particularly complicated.
In common usage, members of various gull species are often referred to as sea gulls or seagulls. This name is used informally to refer to a common local species or all gulls in general, and has no fixed taxonomic meaning.
The American Ornithologists' Union
combines Sternidae
, Stercorariidae
, and Rhynchopidae
as subfamilies
in the family Laridae, but recent research indicates that this is incorrect.
This is a list of gull species, presented in taxonomic sequence
.
Genus Larus
Genus Ichthyaetus
Genus Leucophaeus
Genus Chroicocephalus
Genus Saundersilarus
Genus Hydrocoloeus
Genus Rhodostethia
Genus Rissa
Genus Pagophila
Genus Xema
Genus Creagrus
evidence since the Early Oligocene, some 30-33 ma (million years) ago. A fossil gull from the Middle
to Late
Miocene
of Cherry County, Nebraska
, USA
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, "Larus" elegans and "L." totanoides from the Late Oligocene/Early Miocene
of southeast France
have since been separated in Laricola.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Laridae. They are most closely related to the tern
Tern
Terns are seabirds in the family Sternidae, previously considered a subfamily of the gull family Laridae . They form a lineage with the gulls and skimmers which in turn is related to skuas and auks...
s (family Sternidae) and only distantly related to auk
Auk
An auk is a bird of the family Alcidae in the order Charadriiformes. Auks are superficially similar to penguins due to their black-and-white colours, their upright posture and some of their habits...
s, skimmer
Skimmer
The Skimmers, Rynchopidae, are a small family of tern-like birds in the order Charadriiformes, which also includes the waders, gulls and auks. The family comprises three species found in South Asia, Africa, and the Americas....
s, and more distantly to the wader
Wader
Waders, called shorebirds in North America , are members of the order Charadriiformes, excluding the more marine web-footed seabird groups. The latter are the skuas , gulls , terns , skimmers , and auks...
s. Until the twenty-first century most gulls were placed in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Larus
Larus
Larus is a large genus of gulls with worldwide distribution . Many of its species are abundant and well-known birds in their ranges...
, but this arrangement is now known to be polyphyletic
Polyphyly
A polyphyletic group is one whose members' last common ancestor is not a member of the group.For example, the group consisting of warm-blooded animals is polyphyletic, because it contains both mammals and birds, but the most recent common ancestor of mammals and birds was cold-blooded...
, leading to the resurrection of several genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...
.
Gulls are typically medium to large birds, usually grey or white, often with black markings on the head or wings. They typically have harsh wailing or squawking calls, stout, longish bill
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
s, and webbed feet. Most gulls, particularly Larus species, are ground-nesting carnivore
Carnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
s, which will take live food or scavenge
Scavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...
opportunistically. Live food often includes crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s and small fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
. Gulls have prophylactic unhinging jaws which allow them to consume large prey. Apart from the kittiwake
Kittiwake
The kittiwakes are two closely related seabird species in the gull family Laridae, the Black-legged Kittiwake and the Red-legged Kittiwake . The epithets "Black-legged" and "Red-legged" are used to distinguish the two species in North America, but in Europe, where R...
s, gulls are typically coastal or inland species, rarely venturing far out to sea 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.
Gulls nest in large, densely packed noisy colonies
Bird colony
A bird colony is a large congregation of individuals of one or more species of bird that nest or roost in close proximity at a particular location. Many kinds of birds are known to congregate in groups of varying size; a congregation of nesting birds is called a breeding colony...
. They lay two to three speckled eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
in nests
Bird nest
A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American Robin or Eurasian Blackbird, or the elaborately woven hanging nest of the...
composed of vegetation. The young are precocial
Precocial
In biology, the term precocial refers to species in which the young are relatively mature and mobile from the moment of birth or hatching. The opposite developmental strategy is called "altricial," where the young are born or hatched helpless. Extremely precocial species may be called...
, being born with dark mottled down
Down feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...
, and mobile upon hatching.
Gulls—the larger species in particular—are resourceful, inquisitive and intelligent birds, demonstrating complex methods of communication and a highly developed social structure. For example, many gull colonies display mobbing behaviour, attacking and harassing would-be predators and other intruders. Certain species (e.g. the Herring Gull
Herring Gull
The European Herring Gull is a large gull , and is the most abundant and best known of all gulls along the shores of western Europe. It breeds across Northern Europe, Western Europe, Scandinavia and the Baltic states...
) have exhibited tool use behaviour
Tool use by animals
Tools are used by some animals, particularly primates, to perform simple tasks such as the acquisition of food, or grooming. Originally thought to be a skill only possessed by humans, tool use requires some level of intelligence. Primates have been observed exploiting sticks and stones to...
, using pieces of bread as bait
Bait (luring substance)
Bait is any substance used to attract prey, e.g. in a mousetrap.-In Australia:Baiting in Australia refers to specific campaigns to control foxes, wild dogs and dingos by poisoning in areas where they are a problem...
with which to catch goldfish
Goldfish
The goldfish is a freshwater fish in the family Cyprinidae of order Cypriniformes. It was one of the earliest fish to be domesticated, and is one of the most commonly kept aquarium fish....
, for example. Many species of gull have learned to coexist successfully with humans and have thrived in human habitats
Urban wildlife
Urban wildlife is wildlife that can live or thrive in urban environments. Some urban wildlife, such as house mice, are synanthropic, ecologically associated with humans. Different types of urban area support different kinds of wildlife...
. Others rely on kleptoparasitism
Kleptoparasitism
Kleptoparasitism or cleptoparasitism is a form of feeding in which one animal takes prey or other food from another that has caught, collected, or otherwise prepared the food, including stored food...
to get their food. Gulls have been observed preying on live whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
s, landing on the whale as it surfaces to peck out pieces of flesh.
Description and morphology
Little Gull
The Little Gull, Hydrocoloeus minutus or Larus minutus, is a small gull which breeds in northern Europe and Asia. It also has small colonies in parts of southern Canada. It is migratory, wintering on coasts in western Europe, the Mediterranean and the northeast USA. As is the case with many gulls,...
, at 120 g (4.2 oz) and 29 cm (11.5 inches), to the Great Black-backed Gull
Great Black-backed Gull
The Great Black-backed Gull is the largest gull in the world, which breeds on the European and North American coasts and islands of the North Atlantic...
, at 1.75 kg (3.8 lbs) and 76 cm (30 inches). They are generally uniform in shape, with heavy bodies, long wings, moderately long necks . The tails of all but three species are rounded; the exceptions being the Sabine's Gull
Sabine's Gull
The Sabine's Gull is a small gull. Its generic placement is disputed; some authors treat it as the sole species in the genus Xema as Xema sabini, while others retain it in the genus Larus as Larus sabini. It breeds in the arctic and has a circumpolar distribution through northernmost North America...
and Swallow-tailed Gull
Swallow-tailed Gull
The Swallow-tailed Gull 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, also from kreas, meat; according to Jobling it would mean "hook for meat" referring to the...
s, which have forked tails, and the Ross's Gull
Ross's Gull
The Ross's Gull 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....
, which has a wedge-shaped tail. Gulls have moderately long legs (certainly longer than the 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
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
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
Ivory Gull
The Ivory Gull Pagophila eburnea is a small gull, the only species in its genus. It breeds in the high arctic and has a circumpolar distribution through Greenland, northernmost North America, and Eurasia.-Taxonomy:...
is entirely white, and some like the Lava Gull
Lava Gull
The Lava Gull is a large gull. One of the rarest gulls in the world, the entire population lives on the Galapagos Islands and is estimated at 400 pairs....
and Heermann's Gull
Heermann's Gull
The Heermann's Gull is a gull resident in the United States, Mexico and extreme southwestern British Columbia. Of the current population of about 150,000 pairs, 90% nest on the island of Isla Rasa off Baja California in the Gulf of California, with smaller colonies as far north as California and...
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 makings. The head of gulls may be covered by a dark hood or be entirely white. The plumage of the head varies by breeding season; in non-breeding dark-hooded gulls the hood is lost, sometimes leaving a single spot behind the eye, and in white-headed gulls non-breeding heads may have streaking.
Distribution and habitat
The gulls have a worldwide cosmopolitan distributionCosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
. They breed on every continent, including the margins of Antarctica, 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
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
. Many species breed in costal colonies, with a preference for islands, and one species, the Grey Gull
Grey Gull
This article is about the bird. For the record label, see Grey Gull Records.The Grey Gull is a gull found along the Pacific coast of South America...
, breeds in the interior of dry deserts far from water. There is considerable variety in the family and species may breed and feed in marine, freshwater or terrestrial habitats.
Most gull species are migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, with birds moving to warmer habitats during the winter, but the extent to which they migrate varies by species. Some species migrate long distances, like the Franklin's Gull
Franklin's Gull
The Franklin's Gull is a small gull.-Description:It breeds in central provinces of Canada and adjacent states of the northern United States...
, 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 costs near their breeding sites.
Diet and feeding
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 and invertebrates such as insects and earthworms, rodents, eggs, carrion, offal, 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 non-breeding season when birds spend more time on large bodies of water.In addition to taking a wide range prey items 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
Hawking (birds)
Hawking is a feeding strategy in birds involving catching flying insects in the air. The term usually refers to a technique of sallying out from a perch to snatch an insect and then returning to the same or a different perch...
insects on the wing; larger species perform this feat more rarely. Gulls on the wing will also snatch items both off water and off the ground, and over water they will 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. A unique method of obtaining prey to gulls involves dropping heavy shells of clams and mussels onto hard surfaces. Gulls may fly some distance in order to find a suitable surface on which to drop shells, and there is apparently a learnt component to the task 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. It has been suggested that the time taken to learn foraging skills explains the delayed maturation in gulls.
Gulls have only a limited ability to dive below the water in order to feed on deeper prey. In order to obtain prey from deeper down many species of gull feed in association with other animals, where marine hunters drive prey to the surface when hunting. Examples of such associations include four species of gull feeding around plumes of mud brought to the surface by feeding Grey Whales, and also between Orca
Orca
The killer whale , commonly referred to as the orca, and less commonly as the blackfish, is a toothed whale belonging to the oceanic dolphin family. Killer whales are found in all oceans, from the frigid Arctic and Antarctic regions to tropical seas...
s and Kelp Gull
Kelp Gull
The Kelp Gull , also known as the Dominican Gull, breeds on coasts and islands through much of the southern hemisphere. The race L. d. vetula occurs around southern Africa, and nominate L. d...
s (and other seabirds).
Breeding
Gulls are monogamousMonogamy
Monogamy /Gr. μονός+γάμος - one+marriage/ a form of marriage in which an individual has only one spouse at any one time. In current usage monogamy often refers to having one sexual partner irrespective of marriage or reproduction...
and colonial 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 cost that persists for a number of years after the break up, and is thought to be selected against. Gulls also display high levels of site fidelity
Philopatry
Broadly, philopatry is the behaviour of remaining in, or returning to, an individual's birthplace. More specifically, in ecology philopatry is the behaviour of elder offspring sharing the parental burden in the upbringing of their siblings, a classic example of kin selection...
, 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
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
, 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
The European Herring Gull is a large gull , and is the most abundant and best known of all gulls along the shores of western Europe. It breeds across Northern Europe, Western Europe, Scandinavia and the Baltic states...
to just a tiny area of cliff ledge in the kittiwake
Kittiwake
The kittiwakes are two closely related seabird species in the gull family Laridae, the Black-legged Kittiwake and the Red-legged Kittiwake . The epithets "Black-legged" and "Red-legged" are used to distinguish the two species in North America, but in Europe, where R...
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.
Bonaparte's Gull
The Bonaparte's Gull is a small gull.The Bonaparte's Gull is a small species, larger only than the Little Gull and the Saunders's Gull among all gull species. Adults are long with a wingspan and a body mass of . They have a black hood and a short thin dark bill. The body is mainly white with...
s. Species that nest in marshes must construct a nesting platform in order 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 isn't always exactly equal.
Clutch size
Clutch (eggs)
A clutch of eggs refers to all the eggs produced by birds or reptiles, often at a single time, particularly those laid in a nest.In birds, destruction of a clutch by predators, , results in double-clutching...
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 will synchronise their laying, with synchronisation being higher in larger colonies, although after a certain level 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.
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 are often at least one parent will remain with them until they fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
in order 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 taxonomyTaxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
of gulls is confused by their widespread distribution zones of hybridization leading to geneflow. Some have traditionally been considered ring species
Ring species
In biology, a ring species is a connected series of neighboring populations, each of which can interbreed with closely sited related populations, but for which there exist at least two "end" populations in the series, which are too distantly related to interbreed, though there is a potential gene...
, 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, leading to the resurrection of the genera Ichthyaetus
Ichthyaetus
Ichthyaetus is a genus of gulls. They were included in the genus Larus until recently.-Species:*White-eyed Gull, Ichthyaetus leucophthalmus*Sooty Gull, Ichthyaetus hemprichii...
, Chroicocephalus
Chroicocephalus
Chroicocephalus is a genus of medium to relatively small gulls which were once included in the genus Larus. Some authorities also include the Saunders's Gull in Chroicocephalus...
, Leucophaeus
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...
, 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-likeHerring GullThe European Herring Gull is a large gull , and is the most abundant and best known of all gulls along the shores of western Europe. It breeds across Northern Europe, Western Europe, Scandinavia and the Baltic states...
species from California GullCalifornia GullThe 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 may overlap in size greatly with both....
to Lesser Black-backed GullLesser Black-backed GullThe Lesser Black-backed Gull is a large gull that breeds on the Atlantic coasts of Europe. It is migratory, wintering from the British Isles south to West Africa...
in the taxonomic list below. - White-winged gull is used to describe the 4 pale-winged, High Arctic-breeding taxa within the former group; these are Iceland GullIceland GullThe Iceland Gull, Larus glaucoides, is a large gull which breeds in the Arctic regions of Canada and Greenland, but not Iceland, where it is only seen in the winter. It is migratory, wintering from in the North Atlantic as far south as the British Isles and northernmost states of the eastern USA,...
, Glaucous GullGlaucous GullThe Glaucous Gull is a large gull which breeds in the Arctic regions of the northern hemisphere and the Atlantic coasts of Europe. It is migratory, wintering from in the North Atlantic and North Pacific oceans as far south as the British Isles and northernmost states of the USA, also on the Great...
, Thayer's GullThayer's GullThe Thayer's Gull is a large gull native to North America that breeds in the Arctic islands of Canada and primarily winters on the Pacific coast, from southern Alaska to the Gulf of California, though there are also wintering populations on the Great Lakes and the upper Mississippi River...
, and Kumlien's GullKumlien's GullKumlien's Gull, Larus [glaucoides] kumlieni, 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...
.
Hybridisation between species of gull occurs quite frequently, although to varying degrees depending on the species involved (see Hybridisation in gulls
Hybridisation in gulls
Hybridisation in gulls occurs quite frequently, although to varying degrees depending on the species involved.-Hybrid large white-headed gulls:...
). The taxonomy of the large white-headed gulls is particularly complicated.
In common usage, members of various gull species are often referred to as sea gulls or seagulls. This name is used informally to refer to a common local species or all gulls in general, and has no fixed taxonomic meaning.
The American Ornithologists' Union
American Ornithologists' Union
The American Ornithologists' Union is an ornithological organization in the USA. Unlike the National Audubon Society, its members are primarily professional ornithologists rather than amateur birders...
combines Sternidae
Tern
Terns are seabirds in the family Sternidae, previously considered a subfamily of the gull family Laridae . They form a lineage with the gulls and skimmers which in turn is related to skuas and auks...
, Stercorariidae
Skua
The skuas are a group of seabirds with about seven species forming the family Stercorariidae and the genus Stercorarius. The three smaller skuas are called jaegers in North America....
, and Rhynchopidae
Skimmer
The Skimmers, Rynchopidae, are a small family of tern-like birds in the order Charadriiformes, which also includes the waders, gulls and auks. The family comprises three species found in South Asia, Africa, and the Americas....
as subfamilies
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
in the family Laridae, but recent research indicates that this is incorrect.
List of species
Taxonomic sequence
Taxonomic sequence is a sequence followed in listing of taxa which aids ease of use and roughly reflects the evolutionary relationships among the taxa...
.
Larus
Larus is a large genus of gulls with worldwide distribution . Many of its species are abundant and well-known birds in their ranges...
- Pacific GullPacific GullThe Pacific Gull is a very large gull, native to the coasts of Australia. It is moderately common between Carnarvon in the west, and Sydney in the east, although it has become scarce in some parts of the south-east, as a result of competition from the Kelp Gull, which has "self-introduced" since...
, Larus pacificus - Belcher's GullBelcher's GullThe Belcher's Gull , also known as the or Band-tailed Gull, is a gull found along the Pacific coast of South America. It formerly included the very similar Olrog's Gull as a subspecies. It is a medium-sized gull with a blackish mantle, white head and underparts, a black band in the otherwise white...
, Larus belcheri - Olrog's GullOlrog's GullOlrog's Gull is a species of gull found along the Atlantic coast of southern Brazil, Uruguay and northern Argentina. It was formerly considered a subspecies of the very similar L. belcheri. It is a medium-sized gull with a blackish mantle, white head and underparts, a black band in the otherwise...
, Larus atlanticus - Black-tailed GullBlack-tailed GullThe Black-tailed Gull is a medium-sized gull, with a wingspan of 126-128 cm. The bird is resident in East Asia, including China, Taiwan, Japan and Korea. It is a vagrant to Alaska and northeastern North America....
, Larus crassirostris - Heermann's GullHeermann's GullThe Heermann's Gull is a gull resident in the United States, Mexico and extreme southwestern British Columbia. Of the current population of about 150,000 pairs, 90% nest on the island of Isla Rasa off Baja California in the Gulf of California, with smaller colonies as far north as California and...
, Larus heermanni - Common GullCommon GullThe Common Gull or Mew Gull Larus canus is a medium-sized gull which breeds in northern Asia, northern Europe and northwestern North America. It migrates further south in winter...
or Mew Gull, Larus canus - Ring-billed GullRing-billed GullThe Ring-billed Gull is a medium-sized gull.Adults are length and with a wingspan. The head, neck and underparts are white; the relatively short bill is yellow with a dark ring; the back and wings are silver gray; and the legs are yellow. The eyes are yellow with red rims...
, Larus delawarensis - California GullCalifornia GullThe 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 may overlap in size greatly with both....
, Larus californicus - Great Black-backed GullGreat Black-backed GullThe Great Black-backed Gull is the largest gull in the world, which breeds on the European and North American coasts and islands of the North Atlantic...
, Larus marinus - Kelp GullKelp GullThe Kelp Gull , also known as the Dominican Gull, breeds on coasts and islands through much of the southern hemisphere. The race L. d. vetula occurs around southern Africa, and nominate L. d...
, Larus dominicanus (called "Southern Black-backed Gull" or "Karoro" in New Zealand)- Cape Gull, Larus dominicanus vetula
- Glaucous-winged GullGlaucous-winged GullThe Glaucous-winged Gull, Larus glaucescens, is a large, white-headed gull residing from the western coast of Alaska to the coast of Washington. It also breeds on the northwest coast of Alaska. During non-breeding seasons they can be found along the coast of California...
, Larus glaucescens - Western GullWestern GullThe Western Gull, Larus occidentalis, is a large white-headed gull that lives on the western coast of North America. It was previously considered conspecific, the same species, with the Yellow-footed Gull of the Gulf of California...
, Larus occidentalis - Yellow-footed GullYellow-footed GullThe Yellow-footed Gull, Larus livens, is a large gull, closely related to the Western Gull and thought to be a subspecies until the 1960s....
, Larus livens - Glaucous GullGlaucous GullThe Glaucous Gull is a large gull which breeds in the Arctic regions of the northern hemisphere and the Atlantic coasts of Europe. It is migratory, wintering from in the North Atlantic and North Pacific oceans as far south as the British Isles and northernmost states of the USA, also on the Great...
, Larus hyperboreus - Iceland GullIceland GullThe Iceland Gull, Larus glaucoides, is a large gull which breeds in the Arctic regions of Canada and Greenland, but not Iceland, where it is only seen in the winter. It is migratory, wintering from in the North Atlantic as far south as the British Isles and northernmost states of the eastern USA,...
, Larus glaucoides- Kumlien's GullKumlien's GullKumlien's Gull, Larus [glaucoides] kumlieni, 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...
, Larus glaucoides kumlieni
- Kumlien's Gull
- Thayer's GullThayer's GullThe Thayer's Gull is a large gull native to North America that breeds in the Arctic islands of Canada and primarily winters on the Pacific coast, from southern Alaska to the Gulf of California, though there are also wintering populations on the Great Lakes and the upper Mississippi River...
, Larus thayeri - European Herring Gull, Larus argentatus
- Heuglin's GullHeuglin's GullHeuglin's Gull or Siberian Gull, Larus heuglini, is a seabird in the genus Larus. It is closely related to the Lesser Black-backed Gull, Larus fuscus, and is often classified as a subspecies of it...
, Larus heuglini - American Herring GullAmerican Herring GullThe American Herring Gull or Smithsonian Gull is a large gull which breeds in North America. It is often treated as a subspecies of the European Herring Gull but is now regarded as a separate species by some authorities.Adults are white with gray back and wings, black wingtips with white spots,...
, Larus smithsonianus - Yellow-legged GullYellow-legged GullThe Yellow-legged Gull , sometimes referred to as Western Yellow-legged Gull , is a large gull of Europe, the Middle East and North Africa, which has only recently achieved wide recognition as a distinct species...
, Larus michahellis - Caspian GullCaspian GullCaspian Gull is a name applied to the gull taxon Larus cachinnans, a member of the Herring Gull/Lesser Black-backed Gull complex.- Description :...
, Larus cachinnans - East Siberian Herring Gull, Larus vegae
- Armenian GullArmenian GullThe Armenian Gull is a large gull found in the Caucasus and Middle East. It was formerly classified as a subspecies of the Herring Gull but is now generally considered to be a separate species although BirdLife International lumps it with the Yellow-legged Gull The Armenian Gull (Larus armenicus)...
, Larus armenicus - Slaty-backed GullSlaty-backed GullThe Slaty-backed Gull , is a large white-headed gull that breeds on the western coast of Alaska but travels widely during nonbreeding seasons. Claims have been made as to its presence throughout North America as well as the eastern coast of Asia. It is similar in appearance to the Western Gull...
, Larus schistisagus - Lesser Black-backed GullLesser Black-backed GullThe Lesser Black-backed Gull is a large gull that breeds on the Atlantic coasts of Europe. It is migratory, wintering from the British Isles south to West Africa...
, Larus fuscus
Genus Ichthyaetus
Ichthyaetus
Ichthyaetus is a genus of gulls. They were included in the genus Larus until recently.-Species:*White-eyed Gull, Ichthyaetus leucophthalmus*Sooty Gull, Ichthyaetus hemprichii...
- White-eyed GullWhite-eyed GullThe White-eyed Gull is a small gull which 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 just 4,000 - 6,500 pairs. The species is classed as Near Threatened by the IUCN; human pressure and oil pollution are deemed the...
, Ichthyaetus leucophthalmus - Sooty GullSooty GullThe Sooty Gull is a species of gull in the Laridae family.It is found in Bahrain, Djibouti, Egypt, Eritrea, India, Iran, Israel, Jordan, Kenya, Lebanon, Maldives, Mozambique, Oman, Pakistan, Qatar, Saudi Arabia, Somalia, Sri Lanka, Sudan, Tanzania, United Arab Emirates, and Yemen...
, Ichthyaetus hemprichii - Great Black-headed GullGreat Black-headed GullThe Pallas's Gull or Great Black-headed Gull, Ichthyaetus ichthyaetus, is a large gull. As is the case with many gulls, it has traditionally been placed in the genus Larus....
, Ichthyaetus ichthyaetus - Audouin's GullAudouin's GullThe Audouin's Gull is a large gull restricted to the Mediterranean and the western coast of Saharan Africa. It breeds on small islands colonially or alone, laying 2-3 eggs on a ground nest...
, Ichthyaetus audouinii - Mediterranean GullMediterranean GullThe Mediterranean Gull, Ichthyaetus melanocephalus, is a small gull which breeds almost entirely in Europe, mainly in the south east, especially around the Black Sea, and in central Turkey. There are colonies elsewhere in southern Europe, and this species has undergone a dramatic range expansion in...
, Ichthyaetus melanocephalus - Relict GullRelict GullThe Relict Gull, Ichthyaetus relictus, is a medium-sized gull. It was believed to be an eastern race of the Mediterranean Gull until 1971 and was traditionally placed in the genus Larus.-Description:...
, Ichthyaetus relictus
Genus Leucophaeus
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...
- Dolphin GullDolphin GullThe Dolphin Gull , sometimes erroneously called the Red-billed Gull , is a gull native to southern Chile and Argentina, and the Falkland Islands. It is a coastal bird inhabiting rocky, muddy and sandy shores and is often found around seabird colonies...
, Leucophaeus scoresbii - Laughing GullLaughing GullThe Laughing Gull, Leucophaeus atricilla, is a medium-sized gull of North and South America. It breeds on the Atlantic coast of North America, the Caribbean, and northern South America. Northernmost populations migrate further south in winter, and this species occurs as a rare vagrant to western...
, Leucophaeus atricilla - Franklin's GullFranklin's GullThe Franklin's Gull is a small gull.-Description:It breeds in central provinces of Canada and adjacent states of the northern United States...
, Leucophaeus pipixcan - Lava GullLava GullThe Lava Gull is a large gull. One of the rarest gulls in the world, the entire population lives on the Galapagos Islands and is estimated at 400 pairs....
, Leucophaeus fuliginosus - Gray Gull, Leucophaeus modestus
Genus Chroicocephalus
Chroicocephalus
Chroicocephalus is a genus of medium to relatively small gulls which were once included in the genus Larus. Some authorities also include the Saunders's Gull in Chroicocephalus...
- Silver GullSilver GullThe Silver Gull also known simply as "seagull" in Australia, is the most common gull seen in Australia. It has been found throughout the continent, but particularly coastal areas. The South African Hartlaub's Gull and the New Zealand Red-billed Gull The Silver Gull (Chroicocephalus...
, Chroicocephalus novaehollandiae - Red-billed GullRed-billed GullThe Red-billed Gull , once also known as the Mackerel Gull, is a native of New Zealand, being found throughout the country and on outlying islands including the Chatham Islands and Sub-antarctic islands.The Māori name of this species is Tarapunga or Akiaki...
, Chroicocephalus scopulinus - Hartlaub's GullHartlaub's GullThe Hartlaub's Gull or King Gull, is a small gull, which is a non-migratory breeding resident endemic to the Atlantic Ocean coastline of South Africa and Namibia. Although it is predominantly coastal or estuarine, it is not a pelagic species, and is rarely seen at sea far from land...
, Chroicocephalus hartlaubii - Brown-hooded GullBrown-hooded GullThe Brown-hooded Gull is a species of gull in the Laridae family. As is the case with many gulls, it has traditionally been placed in the genus Larus....
, Chroicocephalus maculipennis - Gray-hooded Gull, Chroicocephalus cirrocephalus
- Andean GullAndean GullThe Andean Gull is a species of gull in the Laridae family. As is the case with many gulls, it has traditionally been placed in the genus Larus.It is found in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru....
, Chroicocephalus serranus - Black-billed GullBlack-billed GullThe Black-billed Gull is a species of gull in the Laridae family.It is endemic to New Zealand. As is the case with many gulls, it has traditionally been placed in the genus Larus, but is now considered to be the genus Chroicocephalus...
, Chroicocephalus bulleri - Brown-headed GullBrown-headed GullThe Brown-headed Gull, Chroicocephalus brunnicephalus, is a small gull which breeds in the high plateaus of central Asia from Turkmenistan to Mongolia. It is migratory, wintering on the coasts and large inland lakes of tropical southern Asia...
, Chroicocephalus brunnicephalus - Black-headed GullBlack-headed GullThe Black-headed Gull is a small gull which breeds in much of Europe and Asia, and also in coastal eastern Canada. Most of the population is migratory, wintering further south, but some birds in the milder westernmost areas of Europe are resident...
, Chroicocephalus ridibundus - Slender-billed GullSlender-billed GullThe Slender-billed Gull, Chroicocephalus genei, is a mid-sized gull which breeds very locally around the Mediterranean and the north of the western Indian Ocean on islands and coastal lagoons. Most of the population is somewhat migratory, wintering further south to north Africa and India, and a...
, Chroicocephalus genei - Bonaparte's GullBonaparte's GullThe Bonaparte's Gull is a small gull.The Bonaparte's Gull is a small species, larger only than the Little Gull and the Saunders's Gull among all gull species. Adults are long with a wingspan and a body mass of . They have a black hood and a short thin dark bill. The body is mainly white with...
, Chroicocephalus philadelphia
Genus Saundersilarus
- Saunders's GullSaunders's GullSaunders's Gull is a species of gull in the Laridae family.It is found in China, Hong Kong, Japan, North Korea, South Korea, Macau, Russia, Taiwan, and Vietnam....
, Saundersilarus saundersi
Genus Hydrocoloeus
- Little GullLittle GullThe Little Gull, Hydrocoloeus minutus or Larus minutus, is a small gull which breeds in northern Europe and Asia. It also has small colonies in parts of southern Canada. It is migratory, wintering on coasts in western Europe, the Mediterranean and the northeast USA. As is the case with many gulls,...
, Hydrocoloeus minutus
Genus Rhodostethia
- Ross's GullRoss's GullThe Ross's Gull 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....
, Rhodostethia rosea
Genus Rissa
Kittiwake
The kittiwakes are two closely related seabird species in the gull family Laridae, the Black-legged Kittiwake and the Red-legged Kittiwake . The epithets "Black-legged" and "Red-legged" are used to distinguish the two species in North America, but in Europe, where R...
- Black-legged KittiwakeBlack-legged KittiwakeThe Black-legged Kittiwake is a seabird species in the gull family Laridae.This species was first described by Linnaeus in his Systema naturae in 1758 as Larus tridactylus....
, Rissa tridactyla - Red-legged KittiwakeRed-legged KittiwakeThe Red-legged Kittiwake is a seabird species in the gull family Laridae. It breeds in the Pribilof, Bogoslof and Buldir islands of the USA, and the Commander Islands, Russia. Adults are long, with an wingspan and a body mass of ....
, Rissa brevirostris
Genus Pagophila
- Ivory GullIvory GullThe Ivory Gull Pagophila eburnea is a small gull, the only species in its genus. It breeds in the high arctic and has a circumpolar distribution through Greenland, northernmost North America, and Eurasia.-Taxonomy:...
, Pagophila eburnea
Genus Xema
- Sabine's GullSabine's GullThe Sabine's Gull is a small gull. Its generic placement is disputed; some authors treat it as the sole species in the genus Xema as Xema sabini, while others retain it in the genus Larus as Larus sabini. It breeds in the arctic and has a circumpolar distribution through northernmost North America...
, Xema sabini
Genus Creagrus
- Swallow-tailed GullSwallow-tailed GullThe Swallow-tailed Gull 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, also from kreas, meat; according to Jobling it would mean "hook for meat" referring to the...
, Creagrus furcatus'
Evolution
The Laridae are known from fossilFossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
evidence since the Early Oligocene, some 30-33 ma (million years) ago. A fossil gull from the Middle
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....
to Late
Late Miocene
The Late Miocene is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch....
Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
of Cherry County, Nebraska
Cherry County, Nebraska
Cherry County is unusual in being split between two time zones, Mountain Time and Central Time. The lines between the two runs roughly north to south along the eastern third of the county. Cherry County is also the location of the Valentine National Wildlife Refuge, the Fort Niobrara National...
, USA
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
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, "Larus" elegans and "L." totanoides from the Late Oligocene/Early Miocene
Early Miocene
The Early Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages....
of southeast France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
have since been separated in Laricola.
External links
- Rudy's Gull-index Pictures of less well-known plumages of large gulls
- Gull videos on the Internet Bird Collection
- Gullpix Pictures of gulls, sorted by species