Rock shag | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Suliformes |
Family: | Phalacrocoracidae |
Genus: | Leucocarbo |
Species: | L. magellanicus |
Binomial name | |
Leucocarbo magellanicus (Gmelin, 1789) | |
Nonbreeding Year-round | |
Synonyms | |
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The rock shag (Leucocarbo magellanicus), also known as the Magellanic cormorant, is a marine cormorant found around the southernmost coasts of South America. Its breeding range is from around Valdivia, Chile, south to Cape Horn and Tierra del Fuego, and north to Punta Tombo in Argentina. In winter it is seen further north, with individuals reaching as far as Santiago, Chile on the west coast and Uruguay on the east. The birds also breed around the coasts of the Falkland Islands.
The rock shag was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae . He placed it in the genus Pelecanus and coined the binomial name Pelecanus magellanicus. [2] Gmelin based his description on the "Magellanic shag" that had been described in 1785 by the English ornithologist John Latham in his book A General Synopsis of Birds. Latham had in turn based his description on a specimen in the Leverian Museum and the account made by Georg Forster of his visit to Tierra del Fuego in December 1774 during James Cook's second voyage to the Pacific. [3] [4] The rock shag was formerly placed in the genus Phalacrocorax but based on the results of a molecular genetic study of the cormorants published in 2014, the species was moved to the genus Leucocarbo . [5] [6] [7] The genus had been introduced in 1856 by the French naturalist Charles Lucien Bonaparte. [8] The genus name combines the Ancient Greek leukos meaning "white" with the name Carbo introduced by Bernard Germain de Lacépède in 1799. [9] The species is monotypic: no subspecies are recognised. [7]
At a distance, the rock shag is a black and white bird, with head, neck and upperparts black and chest and underparts white. Closer up, the black areas vary from metallic blue to oily green, and are flecked with white in places. The legs and feet are a pink, fleshy colour, and the bare flesh around the beak and eyes is brick red. In breeding condition, there is a blackish though not very prominent crest on the forehead, and a distinctive white ear patch. There is even less sexual dimorphism than in most cormorant species, but males are 5%-10% larger on most size measurements.
Like all cormorants, the rock shag feeds by diving for underwater prey. It feeds close to shore, often diving at the edge of kelp beds and apparently finding small fish (predominantly cod icefishes, Patagonotothen species) sheltering among the weed. Studies with depth gauges suggest that it is a fairly shallow diver, typically going about 5 m below the surface with few individuals diving deeper than 10 m, although its prey mainly comes from the sea floor. Dive times are typically around 30 seconds. Its breeding range overlaps markedly with that of the imperial shag Leucocarbo atriceps, but the two species' foraging ranges are different since the imperial shag tends to dive in deeper water, further out from shore.
The rock shag usually nests on ledges on steep, bare, rocky cliffs. It normally lays three eggs, though nests of from two to five eggs have been seen. Nesting colonies range is size from five pairs to nearly 400.
Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the International Ornithologists' Union (IOU) adopted a consensus taxonomy of seven genera. The great cormorant and the common shag are the only two species of the family commonly encountered in Britain and Ireland and "cormorant" and "shag" appellations have been later assigned to different species in the family somewhat haphazardly.
The pelagic cormorant, also known as Baird's cormorant or violet-green cormorant, is a small member of the cormorant family Phalacrocoracidae. Analogous to other smallish cormorants, it is also called the pelagic shag occasionally. This seabird lives along the coasts of the northern Pacific; during winter it can also be found in the open ocean. Pelagic cormorants have relatively short wings due to their need for economical movement underwater, and consequently have the highest flight costs of any bird.
The European shag or common shag is a species of cormorant. It is the only member of the monotypic genus Gulosus. It breeds around the rocky coasts of western and southern Europe, southwest Asia and north Africa, mainly wintering in its breeding range except for the northernmost birds. In Britain this seabird is usually referred to as simply the shag. The scientific genus name derives from the Latin for glutton. The species name aristotelis commemorates the Greek philosopher Aristotle.
The Australian pied cormorant, also known as the pied cormorant, pied shag, or great pied cormorant, is a medium-sized member of the cormorant family. It is found around the coasts of Australasia. In New Zealand, it is usually known either as the pied shag or by its Māori name of kāruhiruhi. Older sources may refer to it as the "yellow-faced cormorant".
The pink-backed pelican is a bird of the pelican family. It is a resident breeder in the swamps and shallow lakes of Africa and southern Arabia; it has also apparently been extirpated from Madagascar.
The reed cormorant, also known as the long-tailed cormorant, is a bird in the cormorant family Phalacrocoracidae. It breeds in much of Africa south of the Sahara, and Madagascar. It is resident but undertakes some seasonal movements.
The neotropic cormorant or olivaceous cormorant is a medium-sized cormorant found throughout the American tropics and subtropics, from the middle Rio Grande and the Gulf and Californian coasts of the United States south through Mexico and Central America to southern South America, where it is called by the indigenous name of biguá. It also breeds in the Bahamas, Cuba, and Trinidad. It can be found both on coasts and in inland waters. There are at least two subspecies: N. b. mexicanum from Nicaragua northwards and N. b. brasilianum further south. In Peru, the neotropic cormorant is used by the Uru people for fishing.
The guanay cormorant or guanay shag is a member of the cormorant family found on the Pacific coast of Peru and northern Chile. After breeding it spreads south to southern parts of Chile and north to Ecuador, and has also been recorded as far north as Panama and Colombia – probably a result of mass dispersal due to food shortage in El Niño years. Its major habitats include shallow seawater and rocky shores.
The red-faced cormorant, red-faced shag or violet shag, is a bird species of the family Phalacrocoracidae.
The New Zealand king shag, also known as the rough-faced shag, king shag or kawau tūī, is a rare bird endemic to New Zealand. Some taxonomic authorities, including the International Ornithologists' Union, place this species in the genus Leucocarbo. Others place it in the genus Phalacrocorax.
The black-faced cormorant, also known as the black-faced shag, is a medium-sized member of the cormorant family. Upperparts, including facial skin and bill, are black, with white underparts. It is endemic to coastal regions of southern Australia.
The imperial shag or imperial cormorant is a black and white cormorant native to southern South America, primarily in rocky coastal regions, but locally also at large inland lakes. Some taxonomic authorities, including the International Ornithologists' Union, place it in the genus Leucocarbo, others in the genus Phalacrocorax. It is also known as the blue-eyed shag, blue-eyed cormorant and by many other names, and is one of a larger group of cormorants called blue-eyed shags. The taxonomy is very complex, and several former subspecies are often considered separate species.
The Magellanic tapaculo is a small passerine bird in the tapaculo family Rhinocryptidae that is found in southern South America.
The Chatham shag, also known as the Chatham Island shag, is a species of bird in the cormorant and shag family, Phalacrocoracidae. It is endemic to the Chatham Islands of New Zealand. For a long time the species was placed in the genus Phalacrocorax; today it is mostly placed with the other blue-eyed shags of New Zealand and Antarctica in the genus Leucocarbo. Its closest relative is the Otago shag of South Island.
The South Georgia shag, also known as the South Georgia cormorant, is a marine cormorant native to South Georgia and a few other subantarctic islands in the South Atlantic Ocean.
The Heard Island shag, or Heard Island cormorant, is a marine cormorant native to the Australian territory comprising the Heard and McDonald Islands in the Southern Ocean, which is about 4,100 km south-west of Perth, Western Australia.
The Macquarie shag, Macquarie Island shag or Macquarie Island cormorant, is a marine cormorant native to Macquarie Island in the Southern Ocean, about halfway between Australia and Antarctica.
The order Suliformes is an order recognised by the International Ornithologist's Union. Regarding the recent evidence that the traditional Pelecaniformes is polyphyletic, it has been suggested that the group be divided to reflect the true evolutionary relationships; a 2017 study indicated that they are most closely related to Otidiformes (bustards) and Ciconiiformes (storks).
The Crozet shag, also known as the South Georgia cormorant, is a marine cormorant native to the Crozet, Prince Edward and Marion islands in the South Atlantic Ocean.
The Antarctic shag, sometimes referred to as the imperial cormorant, king cormorant, imperial shag, blue-eyed shag or Antarctic cormorant, is the only species of the cormorant family found in the Antarctic. It is sometimes considered conspecific with the Imperial shag.