Pigeon Guillemot
Encyclopedia
The Pigeon Guillemot is a medium-sized alcid endemic
to the Pacific. They closely resemble the other members of the genus
Cepphus
, particularly the Black Guillemot
, which is slightly smaller.
Adult birds have black bodies with a white wing patch broken by a black wedge, a thin dark bill and red legs and feet. They are similar in appearance to the Black Guillemot
but show dark wing linings in flight. In winter, the upper parts are mottled grey and black and the underparts are white. They walk well and habitually have an upright posture.
Their breeding habitat is rocky shores, cliffs and islands on northern often forming small loose colonies. They usually lay their eggs in rocky cavities near water, but will often nest in any available cavity including caves, disused burrows of other seabirds and even old bomb casings. Unlike many alcids, Pigeon Guillemots are diurnal
and lay two eggs
. Because they can feed their chicks constantly throughout the day, the chicks fledge
faster than equivalent sized auks that are only provisioned at night.
Pigeon Guillemots range across the Northern Pacific from the Kuril Islands
and the Kamchatka Peninsula
in Siberia
to coasts in western North America
from Alaska
to California
. After the breeding season birds in Alaska migrate
south to open waters, whereas some birds from California move north to the waters off British Columbia
. Birds usually return to their natal colony to breed.
They dive for food from the surface, swimming underwater, feeding on benthic prey, which is usually obtained close to shore. They mainly eat fish and other aquatic animals, particularly sculpin
s, sandfish
(Trichodon), cod
s, capelin
, and crab
s. Chick diet varies slightly, with more fish than invertebrates, particularly rockfish
.
Endemism in birds
An endemic bird area is a region of the world that contains two or more restricted-range species, while a "secondary area" contains one or more restricted-range species. Both terms were devised by Birdlife International....
to the Pacific. They closely resemble the other members of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Cepphus
Cepphus
Cepphus is a genus of seabirds in the auk family also referred to as true guillemots or, in North America, simply as guillemots. These are medium-sized birds with mainly black plumage in the breeding season, thin dark bills and red legs and feet. Two species have white wing patches, the third has...
, particularly the Black Guillemot
Black Guillemot
The Black Guillemot or Tystie is a medium-sized alcid.Adult birds have black bodies with a white wing patch, a thin dark bill, and red legs and feet. They show white wing linings in flight. In winter, the upperparts are pale grey and the underparts are white. The wings remain black with the large...
, which is slightly smaller.
Adult birds have black bodies with a white wing patch broken by a black wedge, a thin dark bill and red legs and feet. They are similar in appearance to the Black Guillemot
Black Guillemot
The Black Guillemot or Tystie is a medium-sized alcid.Adult birds have black bodies with a white wing patch, a thin dark bill, and red legs and feet. They show white wing linings in flight. In winter, the upperparts are pale grey and the underparts are white. The wings remain black with the large...
but show dark wing linings in flight. In winter, the upper parts are mottled grey and black and the underparts are white. They walk well and habitually have an upright posture.
Diurnal animal
Diurnality is a plant or animal behavior characterized by activity during the day and sleeping at night.-In animals:Animals that are not diurnal might be nocturnal or crepuscular . Many animal species are diurnal, including many mammals, insects, reptiles and birds...
and lay two eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
. Because they can feed their chicks constantly throughout the day, the chicks fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
faster than equivalent sized auks that are only provisioned at night.
Kuril Islands
The Kuril Islands , in Russia's Sakhalin Oblast region, form a volcanic archipelago that stretches approximately northeast from Hokkaidō, Japan, to Kamchatka, Russia, separating the Sea of Okhotsk from the North Pacific Ocean. There are 56 islands and many more minor rocks. It consists of Greater...
and the Kamchatka Peninsula
Kamchatka Peninsula
The Kamchatka Peninsula is a peninsula in the Russian Far East, with an area of . It lies between the Pacific Ocean to the east and the Sea of Okhotsk to the west...
in Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
to coasts in western 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...
from 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 California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. After the breeding season birds in Alaska migrate
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 to open waters, whereas some birds from California move north to the waters off British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
. Birds usually return to their natal colony to breed.
They dive for food from the surface, swimming underwater, feeding on benthic prey, which is usually obtained close to shore. They mainly eat fish and other aquatic animals, particularly sculpin
Sculpin
A Sculpin is a fish that belongs to the order Scorpaeniformes, suborder Cottoidei and superfamily Cottoidea, that contains 11 families, 149 genera, and 756 species...
s, sandfish
Sandfish
Sandfish is a common name of:* Scincus scincus, a skink* Holothuria scabra, a sea cucumber* Beaked sandfish, a genus of fish, see Gonorynchus* Southern sandfish, a familia of fish* Belted sandfish, a species of fish...
(Trichodon), cod
Cod
Cod is the common name for genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
s, capelin
Capelin
The capelin or caplin, Mallotus villosus, is a small forage fish of the smelt family found in the Atlantic and Arctic oceans. In summer, it grazes on dense swarms of plankton at the edge of the ice shelf. Larger capelin also eat a great deal of krill and other crustaceans...
, and crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s. Chick diet varies slightly, with more fish than invertebrates, particularly rockfish
Sebastidae
Sebastidae is a family of marine fish in the order Scorpaeniformes. Their common names include rockfishes, thornyheads and rockcods. Despite the latter name, they are not closely related to the cods in the genus Gadus, nor the rock cod, Lotella rhacina.Not all authorities recognise this family as...
.