Encyclopedia
| Gull
Encyclopedia
|
| Tutorials | Encyclopedia | Dictionary | Directory |
|
Gull
Gulls (often informally Seagulls) are birds in the family Laridae. They are most closely related to the terns (family Sternidae) and only distantly related to auks, and skimmers, and more distantly to the waders. Until recently, most gulls were placed in the genus Larus, but this arrangement is now known to be polyphyletic, leading to the resurrection of several genera.[1] They 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. They have stout, longish bills, and webbed feet. 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).
Biology and habitsMost gulls, particularly Larus species, are ground nesting carnivores, which will take live food or scavenge opportunistically. The live food often includes crabs and small fish. Apart from the kittiwakes, 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. Gulls nest in large, densely packed, and 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 from birth[2]. Gulls?the larger species in particular?are resourceful and highly 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.[3] In addition, certain species (e.g. the Herring Gull) have exhibited tool use behaviour. 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. The urban gull population in the United Kingdom has been growing quickly, probably due to laws such as the Clean Air Act 1956 which prohibited the burning of garbage by local landfill owners, thus increasing the availability of food for the gullshttp://www.ehj-online.com/archive/2000/may2003/may1.htmlhttp://www.birdnomore.com/gulls.htm. TaxonomyThe taxonomy of gulls is confused by their widespread distribution and geneflow leading to zones of hybridization. Some have traditionally been considered ring species, but recent evidence suggest this assumption is questionable.[4] 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, and Hydrocoloeus.[1] 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 by the layman 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 [5][6][7] indicates that this is incorrect. List of speciesThis is a list of gull species, presented in taxonomic sequence. 
Gulls oftentimes take food from people 
A gull hovering 
Gulls flying in the city 
A gull eating a crayfish 
A gull scavenging for food 
A gull attacking a coot 
Gull flying in Prague 
A Seagull defecating
Genus Ichthyaetus
Genus Chroicocephalus
Genus Leucophaeus
Genus Hydrocoloeus
Genus Rissa
Genus Pagophila
Genus Rhodostethia
Genus Xema
Genus Creagrus
EvolutionThe Laridae are known from fossil evidence since the Early Oligocene, some 30-33 mya. A fossil gull from the Middle to Late Miocene of Cherry County, 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. Gallery<gallery> Image:Seagull dropping clam.jpg|Gull dropping a clam Image:Flock of gulls - various species.jpg|An assorted flock of gulls Image:Goeland adulte et juvénile.jpg|Lesser Black-backed Gull - adult gull and her chick Image:Gull ca usa.jpg|Western Gull at Monterey, United States Image:Hatchling Gull chick in egg.jpg|Newly-hatched Lesser Black-backed Gull chick at Steep Holm, Bristol Channel Image:Baby_gull.jpg|Gull chick at Trondheim, Norway Image:Larus ridibundus.jpg|A Black-headed Gull at Devon, England Image:Creagrus furcatus.JPG|The Swallow-tailed Gull, endemic inhabitant of the Galápagos Islands Image:Creagrus furcatus flight.jpg|Swallow-tailed Gull in flight, displaying wing patterns Image:herring.gull.northdevon.arp.750pix.jpg|Herring Gull on the North Devon coast, England Image:Seagull on sale pier.jpg|Silver Gull at Sale, Australia Image:Chesapeake Bay gulls soaring.jpg|Ring-billed Gulls at Chesapeake Bay Image:Larus-delawarensis-021.jpg|Ring-billed Gull at Toronto, Ontario, Canada Image:Dolphin Gull.jpg|Dolphin Gull at Ushuaia, Tierra del Fuego Image:Seagull_lakes_entrance.jpg|Silver Gull at Lakes Entrance Image:Gulls in air13.jpg|Black-tailed Gulls feeding in flight Image:Heermann's Gull breeding adult.jpg|Heermann's Gulls have mostly greyish plumage with a white head during the breeding season. Image:Lava gull.jpg|Lava Gull at Santa Cruz Island, Galapagos Image:Oeufs goeland argenté.jpg|Herring Gull eggs Image:Larus smithsonianus-USFWS.jpg|American Herring Gull on its nest Image:JuvenileSeaGull.JPG|A juvenile Seagull on Cramond coastal village, Edinburgh </gallery> ReferencesBibliography
External links
ar:???? br:Gouelan ca:Laridae da:Måge de:Möwen eo:Mevo et:Kajaklased es:Gaviota eu:Kaio fa:??? ?????? fr:Goéland fy:Seefûgels gd:Faoileag ko:??? hr:Galebi io:Muevo it:Laridae sw:Shakwe lt:Kiriniai hu:Sirályfélék nl:Meeuwen (vogels) ja:???? (Sibley) no:Måser nn:Måsefamilien nrm:Mauve oc:Laridae pl:Mewy pt:Gaivota (ave) ru:???????? scn:Laridae fi:Lokit sv:Måsar och trutar th:???????? tl:Bako tr:Mart? wa:Måwete zh:? Source: Wikipedia | The above article is available under the GNU FDL. | Edit this article
|
|
top
©2008-2009 TutorGig.com. All Rights Reserved. Privacy Statement
