The red-legged kittiwake (''Rissa brevirostris'') is a

seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ...

species in the

gull 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 only distantly related to auks, and even more distantly to waders. Until the 21st century, m ...

family Laridae. It breeds in the

Pribilof Islands The Pribilof Islands (formerly the Northern Fur Seal Islands; ale, Amiq, russian: Острова Прибылова, Ostrova Pribylova) are a group of four volcanic islands off the coast of mainland Alaska, in the Bering Sea, about north of ...

Bogoslof Island Bogoslof Island or Agasagook Island ( ale, Aĝasaaĝux̂) is the summit of a submarine stratovolcano at the south edge of the Bering Sea, northwest of Unalaska Island of the Aleutian Island chain. It has a land area of and is uninhabited. The pe ...

and

Buldir Island Buldir Island (also sometimes written Buldyr; ale, Idmaax; russian: Булдырь) is a small island in the western Aleutian Islands of the U.S. state of Alaska. It is long and wide with an area of . Buldir is farther from the nearest lan ...

in the

Bering Sea The Bering Sea (, ; rus, Бе́рингово мо́ре, r=Béringovo móre) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and The Ameri ...

off the coast of

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

, and the

Commander Islands The Commander Islands, Komandorski Islands, or Komandorskie Islands (russian: Командо́рские острова́, ''Komandorskiye ostrova'') are a series of treeless, sparsely populated Russian islands in the Bering Sea located about ea ...

, Russia and spends the winter at sea.

Description

The red-legged kittiwake is a very localised

subarctic The subarctic zone is a region in the Northern Hemisphere immediately south of the true Arctic, north of humid continental regions and covering much of Alaska, Canada, Iceland, the north of Scandinavia, Siberia, and the Cairngorms. Generally, ...

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

species. Apart from the distinguishing feature implicit in its name, it is very similar to its better known relative, the

black-legged kittiwake The black-legged kittiwake (''Rissa tridactyla'') is a seabird species in the gull family Laridae. This species was first described by Carl Linnaeus in his landmark 1758 10th edition of ''Systema Naturae'' as ''Larus tridactylus''. The English ...

; other differences include the shorter bill, larger eyes, a larger, rounder head and darker grey wings, and in the juveniles, which barely differ from the adults, lacking the black tail band and 'W' across the wings of juvenile black-legged kittiwakes. Juveniles take three years to reach maturity. Adults are long, with an wingspan and a body mass of .''CRC Handbook of Avian Body Masses'' by John B. Dunning Jr. (Editor). CRC Press (1992), . Like the Pacific race of black-legged kittiwake, the red-legged kittiwake has a well-developed hind toe. As occasional individual black-legged kittiwakes have reddish legs, any reports of red-legged away from the subarctic Pacific must record all of the other differences, not just the leg colour, for acceptance by bird recording authorities.

Behavior

The red-legged kittiwake feeds on fish such as

lanternfish Lanternfishes (or myctophids, from the Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family Myctophidae. One of two families in the order Myctophiformes, the Myctophidae are represente ...

(Myctophidae), squid and invertebrates. It spends the summer at the cliff breeding colonies, nesting on ledges, and migrates out to sea in September to overwinter in the north western Pacific Ocean and the

Gulf of Alaska The Gulf of Alaska (Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, ...

Status

This species is listed as " Vulnerable" by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

as its population appears to be in decline. It has a global population in the region of 337,000 to 377,000 mature individuals and its breeding range is . Its numbers are thought to have decreased by about 35% between the mid-1970s and the mid-1990s though numbers may have stabilized since. It is unclear why they have declined, but it may be related to a change in the availability of prey, possibly associated excessive commercial fishing or with climate change.

Gallery

Image:Rlegkittiwake6.jpg, Red-legged kittiwake Image:Red-legged Kittiwake RWD1.jpg, Alaska SeaLife Center in Seward, Alaska Image:Red-legged Kittiwake RWD3.jpg, Alaska SeaLife Center in Seward, Alaska Image:Rissa brevirostris7.jpg, Red-legged kittiwake chick Image:Red-legged Kittiwake colony, St. George Island, Alaska.jpg, Red-legged kittiwake colony, St. George Island, Alaska

References

* Harrison, Peter (1988). ''Seabirds: An Identification Guide''. London: Christopher Helm. * Malling Olsen, Klaus and Hans Larsson, ''

Gulls of Europe, Asia and North America ''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. The book is intended to succeed Peter J. Grant's '' Gulls: A Guide to Iden ...

'' {{Taxonbar, from=Q1274310 Birds of the Arctic Native birds of Alaska Birds of the Aleutian Islands

red-legged kittiwake The red-legged kittiwake (''Rissa brevirostris'') is a seabird species in the gull family Laridae. It breeds in the Pribilof Islands, Bogoslof Island and Buldir Island in the Bering Sea off the coast of Alaska, and the Commander Islands, Russia ...

Kittiwakes Endemic fauna of Alaska