Sabine's Gull
Encyclopedia
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 Eurasia
. It migrates
south in autumn; most of the population winters at sea in the Pacific off western South America
in the cold waters of the Humboldt Current
, while Greenland
and eastern Canadian bird
s cross the Atlantic
by way of the westernmost fringes of Europe
to winter off southwest Africa
in the cold waters of the Benguela Current
. Occasionally individual Sabine's Gulls can be seen off other coasts such as the northeastern United States
or further east in Europe, typically following autumn storms.
This species is easy to identify through its striking wing pattern. The adult has a pale grey back and wing coverts, black primary flight feathers and white secondaries. The white tail is forked. The male's hood darkens during breeding season. Their bills are black with a yellow tip. Young birds have a similar tricoloured wing pattern, but the grey is replaced by brown, and the tail has a black terminal band. The juveniles take two years to attain full adult plumage. They have a very high-pitched and squeaking call.
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 Tern
s.
The specific epithet and common name honour the Irish scientist Sir Edward Sabine
, who had sent a specimen to his brother Joseph Sabine
; the first description was in 1819.
of the Galapagos. On the basis of this the two species were often thought to be each other's closest relatives, a hypothesis ruled out by a number of behaviour and ecological differences. Mitochondrial DNA studies confirmed this, and the closest relative of the Sabine's Gull is now thought to be the Ivory Gull
, another Arctic species. The two species are thought to have separated a long time ago, around 2 million years ago.
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
. 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
Larus
Larus is a large genus of gulls with worldwide distribution . Many of its species are abundant and well-known birds in their ranges...
as Larus sabini. It breeds in the arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...
and has a circumpolar distribution through northernmost North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
. It migrates
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...
south in autumn; most of the population winters at sea in the Pacific off western South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
in the cold waters of the Humboldt Current
Humboldt Current
The Humboldt Current , also known as the Peru Current, is a cold, low-salinity ocean current that flows north-westward along the west coast of South America from the southern tip of Chile to northern Peru. It is an eastern boundary current flowing in the direction of the equator, and can extend...
, while Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
and eastern Canadian bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s cross the Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
by way of the westernmost fringes of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
to winter off southwest Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
in the cold waters of the Benguela Current
Benguela Current
The Benguela Current is the broad, northward flowing ocean current that forms the eastern portion of the South Atlantic Ocean gyre. The current extends from roughly Cape Point in the south, to the position of the Angola-Benguela Front in the north, at around 16°S. The current is driven by the...
. Occasionally individual Sabine's Gulls can be seen off other coasts such as the northeastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
or further east in Europe, typically following autumn storms.
This species is easy to identify through its striking wing pattern. The adult has a pale grey back and wing coverts, black primary flight feathers and white secondaries. The white tail is forked. The male's hood darkens during breeding season. Their bills are black with a yellow tip. Young birds have a similar tricoloured wing pattern, but the grey is replaced by brown, and the tail has a black terminal band. The juveniles take two years to attain full adult plumage. They have a very high-pitched and squeaking call.
The Sabine's Gull breeds in colonies on coasts and tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
, 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 Tern
Arctic Tern
The Arctic Tern is a seabird of the tern family Sternidae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe, Asia, and North America...
s.
The specific epithet and common name honour the Irish scientist Sir Edward Sabine
Edward Sabine
General Sir Edward Sabine KCB FRS was an Irish astronomer, geophysicist, ornithologist and explorer.Two branches of Sabine's work in particular deserve very high credit: Determination of the length of the seconds pendulum, a simple pendulum whose time period on the surface of the Earth is two...
, who had sent a specimen to his brother Joseph Sabine
Joseph Sabine
Joseph Sabine was an English lawyer, naturalist and writer on horticulture.He was born into a prominent Anglo-Irish family in Tewin, Hertfordshire, the eldest son of Joseph Sabine. His younger brother was Sir Edward Sabine....
; the first description was in 1819.
Taxonomy and evolution
The Sabine's Gull is usually treated as comprising a monotypic genus, it is only placed within the genus Larus when the genus is enlarged. The black bill and notched tail is almost unique within the gulls, characteristics shared only with the Swallow-tailed GullSwallow-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...
of the Galapagos. On the basis of this the two species were often thought to be each other's closest relatives, a hypothesis ruled out by a number of behaviour and ecological differences. Mitochondrial DNA studies confirmed this, and the closest relative of the Sabine's Gull is now thought to be 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:...
, another Arctic species. The two species are thought to have separated a long time ago, around 2 million years ago.