Omissus (Larus argentatus omissus) is a variant of European herring gull. It is largely similar to a common herring gull, but unlike the common species, it has yellow legs.
There is very little research and documentation about the omissus variant, some authors believe that it may be a species of its own.
Omissus can be confused with the Yellow-legged gull, but the omissus does not have as distinctly bright yellow legs as the yellow-legged gull.
Omissus was first described in 1928 by the Russian ornithologist Theodor Pleske
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and distantly related to auks, and even more distantly to waders. Until the 21st century, most gulls were placed in the genus Larus, but that arrangement is now considered polyphyletic, leading to the resurrection of several genera. An older name for gulls is mews, which is cognate with German Möwe, Danish måge, Swedish mås, Dutch meeuw, Norwegian måke/måse, and French mouette, and can still be found in certain regional dialects.
The common gull or sea mew is a medium-sized gull that breeds in the Palearctic. The closely related short-billed gull is sometimes included in this species, which may be known collectively as "mew gull". Many common gulls migrate further south in winter. There are differing accounts as to how the species acquired its vernacular name.
The European herring gull is a large gull, up to 66 cm (26 in) long. It breeds throughout the northern and western coasts of Europe. Some European herring gulls, especially those resident in colder areas, migrate further south in winter, but many are permanent residents, such as in Ireland, Britain, Iceland, or on the North Sea shores. They have a varied diet, including fish, crustaceans, as well as some plants, and are also scavengers, consuming carrion and food left by or stolen from humans.
The 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. However, it has increased dramatically in North America, especially along the east coast. Formerly just a winter visitor to North America, it has increased and occurs in large numbers some winters and birds are now recorded year-round. However, there is serious concern about decline in many parts of its range. The species is on the UK Amber List because the UK is home to 40 per cent of the European population and more than half of these are found at fewer than ten breeding sites.
The yellow-legged gull is a large gull found in Europe, the Middle East and North Africa, which has only recently achieved wide recognition as a distinct species. It was formerly treated as a subspecies of either the Caspian gull L. cachinnans, or more broadly as a subspecies of the herring gull L. argentatus. The genus name is from Latin Larus which appears to have referred to a gull or other large seabird, and the species name honours the German zoologist Karl Michahelles.
The Caspian gull is a large gull and a member of the herring and lesser black-backed gull complex. The scientific name is from Latin. Larus appears to have referred to a gull or other large seabird, and cachinnans means 'laughing', from cachinnare 'to laugh'.
The black-legged kittiwake is a seabird species in the gull family Laridae.
Hybridisation in gulls occurs quite frequently, although to varying degrees depending on the species involved.
Gulls of Europe, Asia and North America by Klaus Malling Olsen and Hans Larsson is a volume in the Helm Identification Guides series of bird identification books.
Thayer's gull is a subspecies of the Iceland gull. It is a large gull native to North America.
The Armenian gull is a large gull found in the Caucasus and the Middle East. It was formerly classified as a subspecies of the European herring gull, but is now generally considered to be a separate species, although BirdLife International lumps it with the yellow-legged gull.
The Vega gull, East Siberian gull, or East Siberian herring gull is a large gull of the herring gull/lesser black-backed gull complex which breeds in Northeast Asia. Its classification is still controversial and uncertain. It is variously treated as a separate species, as a subspecies of the American herring gull or included with both the American herring gull and European herring gull in L. argentatus. The Mongolian gull, Larus mongolicus, has previously been regarded as a subspecies of the Caspian gull but is now sometimes lumped with the Vega gull.
The American herring gull or Smithsonian gull is a large gull that breeds in North America, where it is treated by the American Ornithological Society as a subspecies of herring gull.
Herring gull is a common name for several birds in the genus Larus, all formerly treated as a single species.