Gulls or seagulls are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns (family Sternidae) and only distantly related to auks, skimmers, and more distantly to the waders. Until the 21st century, most gulls were placed in the genus Larus, but this arrangement is now considered polyphyletic, leading to the resurrection of several genera. An older name for gulls is mews, cognate with German Möwe, Danish måge, Dutch meeuw, and French mouette; this term can still be found in certain regional dialects.
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 bills; and webbed feet. Most gulls are ground-nesting carnivores which take live food or scavenge opportunistically, particularly the Larus species. Live food often includes crabs and small fish. 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 kittiwakes. 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 or three speckled eggs in nests composed of vegetation. The young are precocial, 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 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, for example. Many species of gulls 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 whales, landing on the whale as it surfaces to peck out pieces of flesh.
|Adult ring-billed gull|
11, see text
Gulls range in size from the little gull, at 120 g (4.2 oz) and 29 cm (11 in), to the great black-backed gull, at 1.75 kg (3.9 lb) and 76 cm (30 in). 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 and swallow-tailed gulls, which have forked tails, and Ross's gull, 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 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 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.
The gulls have a worldwide cosmopolitan distribution. 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 coastal colonies, with a preference for islands, and one species, the grey gull, 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, 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.
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 and invertebrates such as insects and earthworms, rodents, eggs, carrion, offal, reptiles, amphibians, plant items such as seeds and fruit, human refuse, chips, 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 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. A method of obtaining prey unique to gulls 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 that are known to reside in areas where there is a season of plentiful mice have, over the centuries, developed a specialized method of eating them. First, the gull captures the mouse in a field. Next, the gull flies to a convenient body of water. The gull then regurgitates the mouse and dips it in the water. Biologists who first observed this habit observed it between mating pairs of gulls. This initially led them to believe that the female was washing off the mouse after it had been transported to the breeding area. But when lone gulls, both male and female, began to be seen doing this, it was finally concluded that the mouse, being dry the first time it was swallowed, could become lodged in the gull's throat, a conclusion further corroborated when a male gull was seen to struggle with the ejection of the mouse, the mouse being partially ejected before getting stuck in the gull's throat. After 5 to 6 sizable gulps of water, the mouse was sufficiently moistened to allow the gull to completely eject the mouse. By wetting the mouse, the gull ensures that the mouse does not become lodged in its throat.
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 whales, and also between orcas (largest dolphin species) and kelp gulls (and other seabirds).
Gulls are monogamous 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 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, 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 kittiwakes.
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 gulls. 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 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 for their dependent offspring, a behavior seen in other animal species, like the elephants, wolves, and the fathead minnow.
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, 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.
The family Laridae was introduced (as Laridia) by the French polymath Constantine Samuel Rafinesque in 1815. The taxonomy 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. 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; 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, fulmars, terns, and skuas) may also be referred to as seagulls by the layperson.
Genus Hydrocoloeus (may include Rhodostethia)
The Laridae are known from not-yet-published fossil evidence since the Early Oligocene, some 30–33 million years ago. Three gull-like species were described by Alphonse Milne-Edwards from the early Miocene of Saint-Gérand-le-Puy, France. 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, Milne-Edwards' "Larus" elegans and "L." totanoides from the Late Oligocene/Early Miocene of southeast France have since been separated in Laricola.
The black-headed gull (Chroicocephalus ridibundus) is a small gull that breeds in much of Europe and Asia, and also in coastal eastern Canada. Most of the population is migratory and winters further south, but some birds reside in the milder westernmost areas of Europe. Some black-headed gulls also spend the winter in northeastern North America, where it was formerly known as the common black-headed gull. As is the case with many gulls, it was previously placed in the genus Larus.
The genus name Chroicocephalus is from Ancient Greek khroizo, "to colour", and kephale, "head". The specific ridibundus is Latin for "laughing", from ridere "to laugh".Black-legged kittiwake
The black-legged kittiwake (Rissa tridactyla) 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. The English name is derived from its call, a shrill 'kittee-wa-aaake, kitte-wa-aaake'. The genus name Rissa is from the Icelandic name Rita for this bird, and the specific tridactyla is from Ancient Greek tridaktulos, "three-toed", from tri-, "three-" and daktulos, "toe".In North America, this species is known as the black-legged kittiwake to differentiate it from the red-legged kittiwake, but in Europe, where it is the only member of the genus, it is often known just as kittiwake.Bonaparte's gull
Bonaparte's gull (Chroicocephalus philadelphia) is a member of the gull family Laridae found mainly in northern North America. At 28 to 38 cm (11 to 15 in) in length, it is one of the smallest species of gull. Its plumage is mainly white with grey upperparts. During breeding season, Bonaparte's gull gains a slate-grey hood. The sexes are similar in appearance.Common gull
For the common gull butterfly, see Cepora nerissa.
The common gull (Larus canus) is a medium-sized gull that breeds in northern Asia, northern Europe, and northwestern North America. The North American subspecies is commonly referred to as the mew gull, although that name is also used by some authorities for the whole species. It migrates further south in winter. There are differing accounts as to how the species acquired its vernacular name (see Etymology section below).European herring gull
The European herring gull (Larus argentatus) is a large gull (up to 26 in (66 cm) 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 Europe, Scandinavia and the Baltic states. Some European herring gulls, especially those resident in colder areas, migrate further south in winter, but many are permanent residents, e.g. in Ireland, Britain, Iceland, or on the North Sea shores. European herring gulls have a varied diet, including fish, crustaceans and dead animals as well as some plants.
While herring gull numbers appear to have been harmed in recent years, possibly by fish population declines and competition, they have proved able to survive in human-adapted areas and can often be seen in towns acting as scavengers.Franklin's gull
The 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 for a type of gull.Glaucous gull
The glaucous gull (Larus hyperboreus) is a large gull, the second largest gull in the world. It breeds in Arctic regions of the Northern Hemisphere and winters south to shores of the Holarctic. The genus name is from Latin Larus, which appears to have referred to a gull or other large seabird. The specific hyperboreus is Latin for "northern" from the Ancient Greek Huperboreoi people from the far north "Glaucous" is from Latin glaucus and denotes a bluish-green or grey colour.This gull is migratory, wintering from in the North Atlantic and North Pacific oceans as far south as the British Isles and northernmost states of the United States, also on the Great Lakes. A few birds sometimes reach the southern USA and northern Mexico.Great black-backed gull
The great black-backed gull (Larus marinus), mistakenly called greater black-backed gull by some, is the largest member of the gull family. It breeds on the European and North American coasts and islands of the North Atlantic and is fairly sedentary, though some move farther south or inland to large lakes or reservoirs. The adult great black-backed gull has a white head, neck and underparts, dark grey wings and back, pink legs and yellow bill.Gull-billed tern
The gull-billed tern (Gelochelidon nilotica), formerly Sterna nilotica, is a tern in the family Laridae. It is now considered to be in its own genus. The genus name is from Ancient Greek gelao, "to laugh", and khelidon, "swallow". The specific niloticus is from Latin and means of the Nile.Gull-wing door
A gull-wing door, also known as a falcon-wing door, is an automotive industry term describing car doors that are hinged at the roof rather than the side, as pioneered by the 1952 Mercedes-Benz 300SL race car (W194) and its road-legal version (W198) introduced in 1954.
Opening upwards, the doors evoke the image of a seagull's wings. In French they are portes papillon (butterfly doors). The papillon door, slightly different in its architecture from a gullwing door – designed by Jean Bugatti in 1939 Type 64, 14 years before Mercedes-Benz produced its similar, famous 300SL gullwing door – is a precursor, but is often overlooked when discussing gull-wing design. Conventional car doors are typically hinged at the front-facing edge of the door, with the door swinging outward horizontally.
Apart from the Mercedes-Benz 300SL of the mid-1950s and the experimental Mercedes-Benz C111 of the early 1970s, the best-known examples of road-cars with gull-wing doors are the Bricklin SV-1 from the 1970s, the DMC DeLorean from the 1980s, and the Tesla Model X of the 2010s. Gull-wing doors have also been used in aircraft designs, such as the four-seat single-engine Socata TB series built in France.Kelp gull
The kelp gull (Larus dominicanus), also known as the Dominican gull, is a gull which breeds on coasts and islands through much of the southern hemisphere. The nominate L. d. dominicanus is the subspecies found around South America, parts of Australia (where it overlaps with the Pacific gull), and New Zealand (where it is known as the southern black-backed gull, simply the black-backed gull, or by its Māori name karoro). L. d. vetula (known as the Cape gull) is a subspecies occurring around southern Africa.
The specific name comes from the Dominican Order of friars, who wear black and white habits.Laughing gull
The laughing gull (Leucophaeus atricilla) is a medium-sized gull of North and South America. Named for its laugh-like call, it is an opportunistic omnivore and scavenger. It breeds in large colonies mostly along the Atlantic coast of North America, the Caribbean, and northern South America. The two subspecies are: L. a. megalopterus – which can be seen from southeast Canada down to Central America, and L. a. atricilla which appears from the West Indies to the Venezuelan islands. The laughing gull was long placed in the genus Larus until its present placement in Leucophaeus, which follows the American Ornithologists' Union.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 is a regular winter visitor to the east coast of North America, probably from the breeding population in Iceland.Little gull
The little gull (Hydrocoloeus minutus or Larus minutus), is a small gull that breeds in northern Europe and Asia. The genus name Hydrocoloeus is from Ancient Greek hydro, "water", and koloios, a sort of web-footed bird. The specific minutuscode: lat promoted to code: la is Latin for "small".It also has small colonies in parts of southern Canada. It is migratory, wintering on coasts in western Europe, the Mediterranean and (in small numbers) the northeast United States; in recent years non-breeding birds have summered in western Europe in increasing numbers and in 2016 they successfully nested for the first time in Great Britain at the Royal Society for the Protection of Birds reserve at Loch of Strathbeg reserve in Aberdeenshire. As is the case with many gulls, it has traditionally been placed in the genus Larus. It is the only member of the genus Hydrocoloeus, although it has been suggested that Ross's gull also should be included in this genus.
This species breeds colonially on freshwater marshes, making a lined nest on the ground amongst vegetation. Normally 2–6 eggs are laid.
This is the smallest gull species, with a length of 25–30 cm (9.8–11.8 in), a wingspan of 61–78 cm (24–31 in), and a mass of 68–162 g (2.4–5.7 oz). It is pale grey in breeding plumage with a black hood, dark underwings and often a pinkish flush on the breast. In winter, the head goes white apart from a darker cap and eye-spot. The bill is thin and black and the legs dark red. The flight on rounded wings is somewhat tern-like.
Young birds have black markings on the head and upperparts, and "W" pattern across the wings. They take three years to reach maturity.
These gulls pick food off the water surface, and will also catch insects in the air like a black tern.Pacific gull
The Pacific gull (Larus pacificus) 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 the 1940s.
Much larger than the ubiquitous silver gull, and nowhere near as common, Pacific gulls are usually seen alone or in pairs, loafing around the shoreline, steadily patrolling high above the edge of the water, or (sometimes) zooming high on the breeze to drop a shellfish or sea urchin onto rocks.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.Rural Municipality of Gull Lake No. 139
Gull Lake No. 139 is a rural municipality of 221 rural residents (2006 census) in the southwestern region of Saskatchewan, Canada. The RM was incorporated January 1, 1913. Other urban municipalities in the area include the Town of Gull Lake, and the Village of TompkinsA rural municipality is an administrative district consisting of an elected reeve, councillors, and administrator who provide essential services within their area.Sabine's gull
The Sabine's gull (Xema sabini), also known as the fork-tailed gull or xeme, 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.The Sabine's gull breeds in colonies on coasts and tundra, laying two or three spotted olive-brown eggs in a ground nest lined with grass. It is very pelagic outside the breeding season. It takes a wide variety of mainly animal food, and will eat any suitable small prey. It also steals eggs from nesting colonies of Arctic terns.Silver gull
The silver gull (Chroicocephalus novaehollandiae or Larus novaehollandiae) is the most common gull seen in Australia. It has been found throughout the continent, but particularly at or near coastal areas.
It is smaller than the pacific gull, which is also found in Australia.
The silver gull should not be confused with the herring gull, which is called "silver gull" in many other languages (scientific name Larus argentatus, German Silbermöwe, French Goéland argenté, Dutch zilvermeeuw), but is a much larger, robust gull with no overlap in range.
Gulls (family: Laridae)