| Crozet shag | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Class: | Aves |
| Order: | Suliformes |
| Family: | Phalacrocoracidae |
| Genus: | Leucocarbo |
| Species: | L. melanogenis |
| Binomial name | |
| Leucocarbo melanogenis (Blyth, 1860) | |
| Synonyms | |
| |
The Crozet shag (Leucocarbo melanogenis), 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. [1]
The Crozet shag is a member of the blue-eyed shags group. It has slightly different plumage from other members of its group and occupies a highly specific range, which is why it is recognized as its own species. The breeding plumage of the Crozet shag features black upperparts with green to bluish sheen on the upper wing-coverts. [2] The head, face and neck are black with a slight white coloration below the ears. They possess an average wingspan of 125 cm (49 in) and body length of 70 cm (28 in) with the males of the species being slightly larger overall.
The bird was first described by Edward Blythe in 1860. [3] The name comes from the Crozet Islands, which falls within the habitat of the bird. [4]
The Crozet shag is normally included as a member of the blue-eyed shags. Mitochondrial DNA analysis has shown that the distinction between shags and cormorants, which was used to sort the Crozet shag as a member of the genera Leucocarbo, is not clearly defined. Therefore, the shag is currently conservatively listed as a member of the genus Phalacrocorax, a combination of shags and cormorants into a single genus. It is often treated as a full species, despite limited study into the differences between the genera. [5]
The Crozet shag is an island faring bird that is located primarily in the southern Atlantic and Indian Oceans in the region of sub-Antarctica. Common sightings of the Crozet shag occur on and around Prince Edward Island, Marion Island, and its native Crozet Island. These islands provide the shags with cliff tops and headlands from which to breed effectively and avoid strong coastal winds that have potential to disrupt and destroy potential nests. The Crozet shag is also able to maintain a wide-ranging diet of squid, octopus, molluscs, crustaceans and fish as a result of its heavily aquatic environment.[ citation needed ]
The Crozet shag forages for food during the daytime in the benthic zone of the ocean. [6] Female members of the species have been recorded as diving to a shallower depth than males, who can reach depths of about 50 m (160 ft) below the surface. This example of sexual dimorphism has been theorized to be because female shags will go after smaller prey than males. To make up for this, females are recorded as diving on average an hour more per day than their male counterparts.[ citation needed ]
Crozet shags are a diving bird in the cold polar waters, but they have little blubber and wettable feathers compared to penguins. [6] Their dives are therefore much shorter, usually around one or two minutes. Crozet shags use a lot of energy for these dives because they are easily impacted by the cold ocean waters.[ citation needed ]
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 great cormorant, known as the black shag or kawau in New Zealand, formerly also known as the great black cormorant across the Northern Hemisphere, the black cormorant in Australia, and the large cormorant in India, is a widespread member of the cormorant family of seabirds. The genus name is Latinised Ancient Greek, from φαλακρός and κόραξ, and carbo is Latin for "charcoal".
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 southern rockhopper penguin group, is a species of rockhopper penguin, that is sometimes considered distinct from the northern rockhopper penguin. It occurs in subantarctic waters of the western Pacific and Indian Oceans, as well as around the southern coasts of South America.
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 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 Socotra cormorant is a threatened species of cormorant that is endemic to the Persian Gulf and the south-east coast of the Arabian Peninsula. It is also sometimes known as the Socotran cormorant or, more rarely, as the Socotra shag. Individuals occasionally migrate as far west as the Red Sea coast. Despite its name, it was only confirmed in 2005 that it breeds on the Socotra islands in the Indian Ocean.
The rock shag, 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 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 Campbell shag, also known as the Campbell Island shag, is a species of bird in the family Phalacrocoracidae. It is endemic to Campbell Island. Its natural habitats are open seas and rocky shores. It is a medium-sized bird, around 63 cm in length, with a wingspan of 105 cm, weighing between 1.6 – 2 kg. They only breed on Campbell Island and forage within 10 km of the island. Its unique, looped head and elongated beak allows to easily feed on shellfish and marine invertebrates. This is done through foraging dive cycles of high speed and efficiency.
The red-legged cormorant, also known as the red-legged shag, red-footed cormorant, red-footed shag, Gaimard's cormorant and grey cormorant, is a species of cormorant resident to the coastline of South America. It is the only member of the genus Poikilocarbo. It is non-colonial unlike most seabirds. The red-legged cormorant has not been observed wing-spreading, which is unusual among cormorant species.
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 Kerguelen shag is a species of cormorant endemic to the Kerguelen Islands in the southern Indian Ocean, one of the most isolated places on Earth. Many authorities consider it a subspecies of the imperial shag.
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, about 4100 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. In regard to 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 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.