Thayer's Gull
Encyclopedia
The Thayer's Gull is a large gull
native to North America
that breeds in the Arctic islands of Canada
and primarily winters on the Pacific
coast, from southern Alaska
to the Gulf of California
, though there are also wintering populations on the Great Lakes
and the upper Mississippi River
. The species has occurred a vagrant to Tamaulipas
, Mexico
,1 Japan
,3 Denmark
, and other parts of western Europe
.
Somewhat intermediate between American Herring Gull
and Iceland Gull
in habit and appearance and at times considered conspecific with either species, the adult Thayer's Gull in nonbreeding plumage has a pale gray mantle, with obvious blackish wingtips, and extensive brown streaking on the head and neck. The head, neck, breast, belly, and underwings are primarily white, and the legs are pink. There is a red spot on the lower mandible, and the color of the iris is generally dark. Thayer's Gull reaches a length of 58–63 cm, with a wingspan of 130–140 cm and a weight of approximately 0.72–1.5 kg (del Hoyo et al. 1996). In summer, the head and neck are white, with the bill turning bright yellow with a larger red spot on the lower mandible. Juvenile gulls are brown, with black bills, and black legs which quickly fade to adult pink.
During winter, it is found in small numbers among mixed flocks of large gulls, though it may gather in large numbers in certain locations. In summer, it is found on the tundra of high Arctic islands. These gulls with lay 3 bluish or greenish eggs in nests lined with grass, moss or lichens. Their voice consists of mostly mewing and squealing notes.
There is continuing debate about the taxonomic status of this species, and some authorities consider Thayer's Gull to be the dark-mantled form of Iceland Gull, with Kumlien's Gull
(variously treated as a subspecies of either Thayer's or Iceland Gulls) as an intermediate example, forming a cline
rather than separate species. The American Ornithologists' Union
considered Thayer's Gull a subspecies of American Herring Gull from 1917 until 1973, when they determined it was a separate species from Herring Gull. While numerous papers have since been written suggesting downgrading this species to a subspecies or even a morph of Iceland Gull, the AOU as well as all North American field guides continue to treat Thayer's Gull as a separate species. The British Ornithologists' Union
follows the publication Birds of North America in lumping the three as forms of Iceland Gull.
Both the common and species names honor ornithologist John Eliot Thayer
.
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...
native to 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...
that breeds in the Arctic islands of Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and primarily winters on the Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
coast, from southern Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
to the Gulf of California
Gulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
, though there are also wintering populations on the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
and the upper Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
. The species has occurred a vagrant to Tamaulipas
Tamaulipas
Tamaulipas officially Estado Libre y Soberano de Tamaulipas is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 43 municipalities and its capital city is Ciudad Victoria. The capital city was named after Guadalupe Victoria, the...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
,1 Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
,3 Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
, and other parts of western 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...
.
Somewhat intermediate between American Herring Gull
American Herring Gull
The American Herring Gull or Smithsonian Gull is a large gull which breeds in North America. It is often treated as a subspecies of the European Herring Gull but is now regarded as a separate species by some authorities.Adults are white with gray back and wings, black wingtips with white spots,...
and Iceland Gull
Iceland Gull
The Iceland Gull, Larus glaucoides, is a large gull which breeds in the Arctic regions of Canada and Greenland, but not Iceland, where it is only seen in the winter. It is migratory, wintering from in the North Atlantic as far south as the British Isles and northernmost states of the eastern USA,...
in habit and appearance and at times considered conspecific with either species, the adult Thayer's Gull in nonbreeding plumage has a pale gray mantle, with obvious blackish wingtips, and extensive brown streaking on the head and neck. The head, neck, breast, belly, and underwings are primarily white, and the legs are pink. There is a red spot on the lower mandible, and the color of the iris is generally dark. Thayer's Gull reaches a length of 58–63 cm, with a wingspan of 130–140 cm and a weight of approximately 0.72–1.5 kg (del Hoyo et al. 1996). In summer, the head and neck are white, with the bill turning bright yellow with a larger red spot on the lower mandible. Juvenile gulls are brown, with black bills, and black legs which quickly fade to adult pink.
During winter, it is found in small numbers among mixed flocks of large gulls, though it may gather in large numbers in certain locations. In summer, it is found on the tundra of high Arctic islands. These gulls with lay 3 bluish or greenish eggs in nests lined with grass, moss or lichens. Their voice consists of mostly mewing and squealing notes.
There is continuing debate about the taxonomic status of this species, and some authorities consider Thayer's Gull to be the dark-mantled form of Iceland Gull, with Kumlien's Gull
Kumlien's Gull
Kumlien's Gull, Larus [glaucoides] kumlieni, is a large gull which breeds in the Arctic regions of Canada. It is migratory, wintering from Labrador south to New England and west across the Great Lakes...
(variously treated as a subspecies of either Thayer's or Iceland Gulls) as an intermediate example, forming a cline
Cline (population genetics)
In biology, an ecocline or simply cline describes an ecotone in which a series of biocommunities display continuous gradient...
rather than separate species. The American Ornithologists' Union
American Ornithologists' Union
The American Ornithologists' Union is an ornithological organization in the USA. Unlike the National Audubon Society, its members are primarily professional ornithologists rather than amateur birders...
considered Thayer's Gull a subspecies of American Herring Gull from 1917 until 1973, when they determined it was a separate species from Herring Gull. While numerous papers have since been written suggesting downgrading this species to a subspecies or even a morph of Iceland Gull, the AOU as well as all North American field guides continue to treat Thayer's Gull as a separate species. The British Ornithologists' Union
British Ornithologists' Union
The British Ornithologists' Union aims to encourage the study of birds in Britain, Europe and elsewhere, in order to understand their biology and to aid their conservation....
follows the publication Birds of North America in lumping the three as forms of Iceland Gull.
Both the common and species names honor ornithologist John Eliot Thayer
John Eliot Thayer
John Eliot Thayer was an American amateur ornithologist.Thayer was born in Boston, Massachusetts, the son of Nathaniel Thayer, a banker who built Harvard's Thayer Hall. After graduating from Harvard, Thayer married Evelyn Forbes and settled at the family farm at Lancaster, thirty-five miles west...
.
External links
- Thayer's Gull at Avibase
- Thayer's Gull at eNature
- Thayer's Gull taxonomic history, at Ontario Birds
- Thayer's Gull at USGS
- Flicker Field Guide Birds of the World Photographs