Pigeon guillemot | |
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Adult in breeding plumage | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Charadriiformes |
Family: | Alcidae |
Genus: | Cepphus |
Species: | C. columba |
Binomial name | |
Cepphus columba Pallas, 1811 | |
Range |
The pigeon guillemot (Cepphus columba) ( /ˈɡɪlɪmɒt/ ) is a species of bird in the auk family, Alcidae. One of three species in the genus Cepphus , it is most closely related to the spectacled guillemot. There are five subspecies of the pigeon guillemot; all subspecies, when in breeding plumage , are dark brown with a black iridescent sheen and a distinctive wing patch broken by a brown-black wedge. Its non-breeding plumage has mottled grey and black upperparts and white underparts . The long bill is black, as are the claws. The legs, feet, and inside of the mouth are red. It closely resembles the black guillemot, which is slightly smaller and lacks the dark wing wedge present in the pigeon guillemot.
This seabird is found on North Pacific coastal waters, from Siberia through Alaska to California. The pigeon guillemot breeds and sometimes roosts on rocky shores, cliffs, and islands close to shallow water. In the winter, some birds move slightly south in the northernmost part of their range in response to advancing ice and migrate slightly north in the southern part of their range, generally preferring more sheltered areas.
This species feeds on small fish and marine invertebrates, mostly near the sea floor, that it catches by pursuit diving. Pigeon guillemots are monogamous breeders, nesting in small colonies close to the shore. They defend small territories around a nesting cavity, in which they lay one or two eggs. Both parents incubate the eggs and feed the chicks. After leaving the nest the young bird is completely independent of its parents. Several birds and other animals prey on the eggs and chicks.
The pigeon guillemot is considered to be a least concern species by the International Union for Conservation of Nature due to its large, stable population and wide range. Threats to this bird include climate change, introduced mammalian predators, and oil spills.
The pigeon guillemot is one of three species of auk in the genus Cepphus , the other two being the black guillemot of the Atlantic Ocean and the spectacled guillemot from the Eastern Pacific. It was described in 1811 by Peter Simon Pallas in the second volume of his Zoographia Rosso-Asiatica. [2] A 1996 study looking at the mitochondrial DNA of the auk family found that the genus Cepphus is most closely related to the murrelets from the genus Synthliboramphus . [3] An alternative arrangement, proposed in 2001 using genetic and morphological comparisons, found them as a sister clade to the murres, razorbill, little auk and great auk. [4] Within the genus, the pigeon guillemot and spectacled guillemot are sister species, and the black guillemot is basal within the genus. [3] [4] The pigeon guillemot and the black guillemot form a superspecies. [lower-alpha 1] [5]
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Cladogram showing the relationship of the pigeon guillemot. Based on Friesen (1996). [3] |
There are five recognised subspecies of the pigeon guillemot: [6]
In the binomial name, the genus, Cepphus, is derived from the Greek kepphos, referring to an unknown pale waterbird mentioned by Aristotle among other classical writers, later variously identified as types of seabirds, including gulls, auks and gannets. The specific epithet, columba, is derived both from the Icelandic klumba, meaning "auk", and the Latin columba, meaning "pigeon". Pallas noted in his description of this species that the common name for the related black guillemot was Greenland dove. Snowi is dedicated to Captain Henry James Snow, a British seaman and hunter. The name of the subspecies kaiurka is derived from the Russian kachurka, meaning "petrel". Adiantus is derived from the Greek adiantos, "unwetted". The trinomial epithet of the subspecies C. c. eureka is from the motto of the state of California, which is derived from the Greek heurēka , meaning "I have found it". [7]
The pigeon guillemot is a medium-sized auk, 30 to 37 cm (12 to 15 in) in length and weighing 450 to 550 g (16 to 19 oz). Both sexes are alike in appearance and mass, except for Californian birds where females were found to have larger bills than males. The summer or breeding plumage of the adult is mostly dark brown with a black sheen, with a white wing patch broken by a brown-black wedge. In winter, the upperparts are iridescent black, often with black fringes giving a scalloped appearance, and the underparts and rump are white. The forehead, crown , lores , eye line and ear coverts are black with white tips, sometimes the tips are narrow and the head looks black. [8] In all plumages, the underwings are plain and dark. [9] Adults moult into their winter or non-breeding plumage between August and October, taking around a month to complete and leaving the bird unable to fly for around four weeks. Birds moult into their breeding plumage between January and March. The legs and feet are red, with black claws. The iris is brown and the eye is surrounded by a thin unbroken white eye-ring. The bill is long and black and the inside of the mouth is red. [8]
The juvenile pigeon guillemot resembles a winter adult but has underpart feathers tipped in brown, giving the appearance of barring, more brown feathers in the upperparts and its wing patch is smaller. Its legs are a grey-brown in color. It loses the brown underpart feathers after its first moult two to three months after fledging. Its moult to its first summer plumage is later than adults, happening between March and May, and first summer birds lack the glossy sheen of adults. [8]
The differences between the subspecies are based on body measurements such as the culmen and wing length. These are larger in southern subspecies and smaller further north. The amount of white on the outer primaries and underwing coverts increases in northern subspecies, except for Cepphus columba snowi, where the white is reduced or entirely absent. [6]
The pigeon guillemot walks well and habitually has an upright posture. When sitting it frequently rests on its tarsi. [8] The wings of the pigeon guillemot are shorter and rounder than other auks, reflecting greater adaptation towards diving than flying. It has difficulty taking off in calm conditions without a runway, but once in the air it is faster than the black guillemot, having been recorded at 77 km/h (48 mph), about 20 km/h (12 mph) faster than the black guillemot. [8] In the water it is a strong swimmer on the surface using its feet. [8] When diving, propulsion is provided both by the wings, which beat at a rate of 2.1/s, but unusually for auks also by the feet. [10] Pigeon guillemots have been recorded travelling 75 m (246 ft) horizontally on dives. [11]
The pigeon guillemot is similar to the related black guillemot, but can be distinguished by its larger size, and in the breeding season by its dusky-grey underwing and the dark brown wedge on the white wing patch. [8]
The pigeon guillemot ranges across the Northern Pacific, from the Kuril Islands and the Kamchatka Peninsula in Siberia to coasts in western North America from Alaska to California. This bird's wintering range is more restricted than its breeding season range, the pigeon guillemot usually wintering at sea or on the coasts, from the Pribilof and Aleutian Islands to Hokkaido and southern California. In Alaska, some migrate south because of advancing sea-ice, although others remain in ice leads or ice holes some distance from the edge of the ice sheet. Further south, birds banded in the Farallon Islands in central California have been recorded moving north, as far as Oregon and even British Columbia. [8] It generally is philopatric, meaning it returns to the colony where it hatched to breed, [12] but it sometimes moves long distances after fledging before settling, for example a chick ringed in the Farallones was recorded breeding in British Columbia. [8]
This bird's breeding habitats are rocky shores, cliffs, and islands close to shallow water less than 50 m (160 ft) deep. It is flexible about its breeding site location, the important factor being protection from predators, and it is more commonly found breeding on offshore islands than coastal sea cliffs. In the winter it forages along rocky coasts, often in sheltered coves. Sandy-bottomed water is avoided, presumably because this does not provide the right habitat to feed in. It occasionally can be found further offshore, as far as the continental shelf break. [8] In the Bering Sea and Alaska, it feeds in openings in ice sheets. [6]
Pigeon guillemots are generally diurnal, but have been recorded feeding before dawn and after sunset. They typically sleep in loose groups in sheltered waters or on shore close to water. They typically rest spaced apart, but mated pairs rest close together. Bathing and preening can also happen on shore or at sea. [8]
The pigeon guillemot usually lays its eggs in rocky cavities near water, but it often nests in any available cavity, including caves, disused burrows of other seabirds, and even old bomb casings. [13] It is noted that pigeon guillemots do not inhabit nests with gull eggs, specifically those of the western gull. [14] This guillemot usually retains its nest site, meaning that nest sites are generally used multiple times, although it does not display this behaviour if its mate does not return to breed. [12] The nests are found at a wide range of heights, from about 1 to 55 m (3.3 to 180.4 ft) above sea-level. [5] Nesting sites are defended by established pairs, as is a small territory around the nest entrance of between 1–4 m2 (11–43 sq ft). Both sexes defend the nesting site, although most defence is done by the male. [8]
Foreign eggs in this guillemot's nest are generally removed. Nest competition with Cassin's auklet is occasional, the pigeon guillemot almost always just removing the eggs, and rarely pithing before removal. [14] On the other hand, larger auk species, tufted puffins and rhinoceros auklets, have been reported evicting pigeon guillemots from their nesting crevices. [12]
This guillemot nests at a variety of densities, ranging from a single individual to dense colonies. The nesting density is generally not affected by predation, although on a very local scale, nesting closer to neighbors has a slight advantage. [15] Colonies are attended during the day and, except for birds incubating or brooding, adults do not remain in the colony at night. Birds usually arrive in the colony in the morning, with counts decreasing after early afternoon, when high tide is. Colony attendance is affected by the tide, more appearing when the tide is higher and less when the tide is lower, probably because the prey this bird feeds on is more accessible during low tide, thus more birds are away from the colony. The counts vary the most before laying, while they are relatively stable during incubation and egg laying. [16]
Pigeon guillemots form long-term pair bonds, the pairs usually reuniting each year, although occasionally pairs divorce. [8] The formation of the pair bond is poorly understood. It is thought that form of play known as "water games", which involves chasing of birds on and under the water at sea, and duet-trilling may have a function in maintaining the pair bond or act as a prelude to copulation. [8] [17] The red colour of the mouth may also be a sexual signal. [8]
Usually arriving at its breeding range 40 to 50 days before laying starts, [6] the pigeon guillemot breeds from late April to September. [8] During this time, it generally lays a clutch of one or two eggs. The eggs have grey and brown blotches near the larger end of the egg and range in colour from creamy to pale blue-green. [13] They measure 61.2 mm × 41.0 mm (2.41 in × 1.61 in) on average, but become longer when laid later in the breeding season. Incubated by both sexes, the eggs usually hatch after 26 to 32 days. [13] The chick is brooded continuously by both parents for three days, and then at intervals for another two to four days, after which it is able to control its own body temperature. Both parents are responsible for feeding the chicks, and bring single fish held in the bill throughout the day, but most frequently in the morning. [8]
The chicks usually fledge 34 to 42 days after hatching, [18] although the time taken to fledge has been known to take anywhere from 29 to 54 days. [8] Chicks fledge by leaving the colony and flying to sea, after which they are independent of their parents and receive no post-fledging care. [6] After this, the adult also leaves the colony. [18] Young birds do not breed until at least three years after fledging, [12] with most first breeding at four years of age. [6] While they may not return to breed, two or three year old birds may start attending the breeding colony before they reach sexual maturity, arriving in the colony after the breeding birds. Pigeon guillemots that reach adulthood have an average life-expectancy of 4.5 years, and the oldest recorded individual lived for 14 years. [8]
The pigeon guillemot is a very vocal bird, particularly during the breeding season, [6] and makes several calls, some of which are paired with displays, to communicate with others of its kind. One such display call pairing is the conspicuous hunch-whistle, where the tail is slightly raised, the wings held slightly out and the head thrown back 45-90° while whistling, before snapping back to horizontal. [19] The function of this call is to advertise ownership of a territory. Another call, the trill, denotes ownership over larger distances. Trills can be performed singly or as duets between pairs; if performed as a duet then the call also functions to help reinforce pair bond. [17] Trills are usually given from a resting position, except for the trill-waggle, which has the bird raising its tail, opening its wings and ruffling the feathers of its neck and head, followed by a waggling of its outstretched neck and head. [19] This display is antagonistic in a context where pigeon guillemots are in a group and often is the precursor to an attack. [17] Low whistles are made by unpaired males attempting to attract a mate, and are deeper than hunch-whistles and involve less movement of the head. [19] Other calls made include seeps and cheeps made between mates and screams made in the presence of predators. [17]
The pigeon guillemot forages by itself or in small groups, diving underwater for food, usually close to shore [20] and during the breeding season within 1 km (0.6 mi) of the colony. [6] It forages at depths from 6 to 45 m (20 to 148 ft), but it prefers depths between 15 and 20 m (50 and 70 ft). The dives can range from 10 to 144 seconds, [8] and usually average 87 seconds, with an intermission between dives lasting around 98 seconds. [21] Dives of two to ten seconds are typical when feeding on shoals of sandlance at the water's surface. [8] Smaller prey are probably consumed underwater, but larger organisms are brought to the surface to eat after capture. [8]
The pigeon guillemot mostly feeds on benthic prey found at the lowest level in a body of water close to the sea floor, but it also takes some prey from higher in the water column. It mainly eats fish and other aquatic animals. Fish taken include sculpins, sandfish, cod, and capelin; invertebrates include shrimp and crabs like the pygmy rock crab, and even rarely polychaete worms, gastropods, bivalves and squid. The diet varies greatly, based on where the individual bird is, the season, and also from year to year, as ocean conditions change prey availability. For example, invertebrates are more commonly taken in winter. [8] The foraging method used by this species differs from that of auks in other genera. It hangs upside down above the seafloor, probing with its head for prey and using its feet and wings to maintain position. [10] The chick's diet varies slightly, with more fish than invertebrates, particularly rockfish (family Sebastidae). [13] Specialization in the prey taken by a pigeon guillemot when foraging for its chicks generally results in greater reproductive success, with a high-lipid diet allowing for more growth. [20]
The adult pigeon guillemot requires about 20% of its own weight, or 90 grams (3.2 oz) of food each day. It doubles its rate of fishing when feeding the nestlings. As the nestlings get older, they are fed more, until 11 days after hatching, when the food generally levels out. The food they get, although, starts to decrease about 30 days after hatching. [22]
Avian predation is the most common cause of egg loss in the pigeon guillemot. Species that prey on the nests include the northwestern crow, a common predator of both eggs and chicks, as well as glaucous-winged gulls, stoats and garter snakes. [8] Raccoons are also common predators, preying on eggs, chicks, and adults. [16] Adults are sometimes hunted by bald eagles, peregrine falcons, great horned owls [8] and northern goshawks. [23] In the water, they have been reported to be taken by orca and giant Pacific octopuses. [8]
This bird, especially its chicks, is vulnerable to Aspergillus fumigatus , a fungal disease, while in captivity. [24] It is also vulnerable to the cestode Alcataenia campylacantha . [25] Ticks ( Ixodes uriae ) and fleas ( Ceratophyllus ) have been recorded on chicks as well. [8]
The pigeon guillemot is considered to be a least concern species by the International Union for Conservation of Nature. This is due to multiple factors, including its large population, estimated at 470,000 individuals, its stable population, and its large range, as this bird is thought to occur over a range of 15,400,000 km2 (5,950,000 sq mi). [1] This bird is vulnerable to introduced mammalian predators, [6] such as raccoons. [16] The removal of introduced predators from breeding islands allows the species to recover. [26] Climate change has a negative effect on this bird, and reproductive performance decreases with increased temperatures. [27] It is also particularly vulnerable to oil, [6] [28] and adults near oiled shores display symptoms of hepatocellular injury, where elevated levels of aspartate aminotransferase can be found in the liver. [29] Otherwise, the effects of oil spills on the pigeon guillemot are unclear. [6] [28] Unlike some seabirds, ingestion of plastic does not seem to be a problem for this species. [30]
An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The family contains 25 extant or recently extinct species that are divided into 11 genera.
Seabirds 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 environmental problems and feeding niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period, and modern seabird families emerged in the Paleogene.
The black-throated loon, also known as the Arctic loon and the black-throated diver, is a migratory aquatic bird found in the northern hemisphere, primarily breeding in freshwater lakes in northern Europe and Asia. It winters along sheltered, ice-free coasts of the north-east Atlantic Ocean and the eastern and western Pacific Ocean. This loon was first described by Carl Linnaeus in 1758 and has two subspecies. It was previously considered to be the same species as the Pacific loon, of which it is traditionally considered to be a sister species, although this is debated. In a study that used mitochondrial and nuclear intron DNA, the black-throated loon was found to be sister to a clade consisting of the Pacific loon and two sister species, the common loon and the yellow-billed loon.
Guillemot is the common name for several species of seabird in the Alcidae or auk family. In Europe, the term covers two genera: Uria and Cepphus. In North America the Uria species are called murres and only the Cepphus species are called "guillemots". This word of French origin derives from a form of the name William, cf. French: Guillaume.
The Atlantic puffin, also known as the common puffin, is a species of seabird in the auk family. It is the only puffin native to the Atlantic Ocean; two related species, the tufted puffin and the horned puffin are found in the northeastern Pacific. The Atlantic puffin breeds in Russia, Iceland, Ireland, Norway, Greenland, Newfoundland and Labrador, Nova Scotia, and the Faroe Islands, and as far south as Maine in the west and France in the east. It is most commonly found in the Westman Islands, Iceland. Although it has a large population and a wide range, the species has declined rapidly, at least in parts of its range, resulting in it being rated as vulnerable by the IUCN. On land, it has the typical upright stance of an auk. At sea, it swims on the surface and feeds on zooplankton, small fish, and crabs, which it catches by diving underwater, using its wings for propulsion.
The black-necked grebe or eared grebe is a member of the grebe family of water birds. It was described in 1831 by Christian Ludwig Brehm. There are currently three accepted subspecies, including the nominate subspecies. Its breeding plumage features distinctive ochre-coloured feathers which extend behind its eye and over its ear coverts. The rest of the upper parts, including the head, neck, and breast, are coloured black to blackish brown. The flanks are tawny rufous to maroon-chestnut, and the abdomen is white. In its non-breeding plumage, this bird has greyish-black upper parts, including the top of the head and a vertical stripe on the back of the neck. The flanks are also greyish-black. The rest of the body is a white or whitish colour. The juvenile has more brown in its darker areas. The subspecies californicus can be distinguished from the nominate by the former's usually longer bill. The other subspecies, P. n. gurneyi, can be differentiated by its greyer head and upper parts and by its smaller size. P. n. gurneyi can also be told apart by its lack of a non-breeding plumage. This species is present in parts of Africa, Eurasia, and the Americas.
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The black guillemot or tystie is a medium-sized seabird of the Alcidae family, native throughout northern Atlantic coasts and eastern North American coasts. It is resident in much of its range, but large populations from the high arctic migrate southwards in winter. The bird can be seen in and around its breeding habitat of rocky shores, cliffs and islands in single or smalls groups of pairs. They feed mainly by diving towards the sea floor feeding on fish, crustaceans or other benthic invertebrates. They are listed on the IUCN red list as a species of least concern.
The razorbill, razor-billed auk, or lesser auk is a North Atlantic colonial seabird and the only extant member of the genus Alca of the family Alcidae, the auks. It is the closest living relative of the extinct great auk.
The common murre, also called the common guillemot or foolish guillemot,(Uria aalge) is a large auk. It has a circumpolar distribution, occurring in low-Arctic and boreal waters in the North Atlantic and North Pacific. It spends most of its time at sea, only coming to land to breed on rocky cliff shores or islands.
The thick-billed murre or Brünnich's guillemot is a bird in the auk family (Alcidae). This bird is named after the Danish zoologist Morten Thrane Brünnich. The very deeply black North Pacific subspecies Uria lomvia arra is also called Pallas' murre after its describer. The genus name is from Ancient Greek ouria, a waterbird mentioned by Athenaeus. The species term lomvia is a Swedish word for an auk or diver. The English "guillemot" is from French guillemot probably derived from Guillaume, "William". "Murre" is of uncertain origins, but may imitate the call of the common guillemot.
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The horned puffin is an auk found in the North Pacific Ocean, including the coasts of Alaska, Siberia and British Columbia. It is a pelagic seabird that feeds primarily by diving for fish. It nests in colonies, often with other auks.
The greater crested tern, also called crested tern or swift tern, is a tern in the family Laridae that nests in dense colonies on coastlines and islands in the tropical and subtropical Old World. Its five subspecies breed in the area from South Africa around the Indian Ocean to the central Pacific and Australia, all populations dispersing widely from the breeding range after nesting. This large tern is closely related to the royal and lesser crested terns, but can be distinguished by its size and bill colour.
The black-legged kittiwake is a seabird species in the gull family Laridae.
The pink pigeon is a species of pigeon in the family Columbidae endemic to Mauritius. The pink pigeon nearly became extinct in the 1970s and the 1990s and is still very rare. It is the only Mascarene pigeon that has not become extinct. It was on the brink of extinction in 1991 when only 10 individuals remained, but its numbers have increased due to the efforts of the Durrell Wildlife Conservation Trust since 1977. While the population remains at below 500 birds as of 2011, the IUCN downlisted the species from Critically endangered to Endangered on the IUCN Red List in 2000, and then downlisted it again to Vulnerable in 2018.
The least tern is a species of tern that breeds in North America and locally in northern South America. It is closely related to, and was formerly often considered conspecific with, the little tern of the Old World. Other close relatives include the yellow-billed tern and Peruvian tern, both from South America.
The spectacled guillemot or sooty guillemot is a seabird in the auk family.
The fork-tailed storm petrel is a small seabird of the storm petrel family Hydrobatidae. It is the second-most abundant and widespread storm petrel and is the only bird in its family that is bluish-grey in colour.
The Antarctic tern is a seabird in the family Laridae. It ranges throughout the southern oceans and is found on small islands around Antarctica as well as on the shores of the mainland. Its diet consists primarily of small fish and crustaceans. It is very similar in appearance to the closely related Arctic tern, but it is stockier, and it is in its breeding plumage in the southern summer, when the Arctic tern has shed old feathers to get its non-breeding plumage. The Antarctic tern does not migrate like the Arctic tern does, but it can still be found on a very large range. This tern species is actually more closely related to the South American tern.