Crozet shag

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Crozet shag
Couple de cormorans de Crozet sur nid avec leurs poussins.jpg
Scientific classification OOjs UI icon edit-ltr.svg
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
  • Leucocarbo atriceps melanogenis
  • Phalacrocorax melanogenis

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]

Contents

Characteristics

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.

Taxonomy and distribution

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]

Habitat

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 ]

Behavior

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 ]

Related Research Articles

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<span class="mw-page-title-main">Pelagic cormorant</span> Species of bird

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<span class="mw-page-title-main">Great cormorant</span> Species of bird

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<span class="mw-page-title-main">European shag</span> Species of bird

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<span class="mw-page-title-main">Guanay cormorant</span> Species of bird

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.

<span class="mw-page-title-main">Socotra cormorant</span> Species of bird

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<span class="mw-page-title-main">Black-faced cormorant</span> Species of bird

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.

<span class="mw-page-title-main">Imperial shag</span> Species of bird

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.

<span class="mw-page-title-main">Campbell shag</span> Species of bird

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<span class="mw-page-title-main">Red-legged cormorant</span> Species of bird

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.

<span class="mw-page-title-main">Chatham shag</span> Species of bird

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<span class="mw-page-title-main">Kerguelen shag</span> Species of bird

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<span class="mw-page-title-main">South Georgia shag</span> A species of bird

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.

<span class="mw-page-title-main">Macquarie shag</span> Species of cormorant

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<span class="mw-page-title-main">Suliformes</span> Order of birds

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<span class="mw-page-title-main">Antarctic shag</span> Species of bird

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.

References

  1. Gill, Frank; Donsker, David (eds.). "Hamerkop, Shoebill, pelicans, boobies, cormorants". World Bird List v. 8.2. International Ornithologists' Union. Archived from the original on 23 April 2020. Retrieved 5 January 2019.
  2. Bouglouan, Nicole (ed.). "Crozet Shag" . Retrieved 7 March 2021.
  3. "Crozet Shag (Leucocarbo melanogenis)". Avibase. Retrieved 7 March 2021.
  4. Tremblay, Yann; Bost, Charles-André; Cherel, Yves; Cook, Timothée (2007). "Chick-rearing Crozet shags (Phalacrocorax melanogenis) display sex-specific foraging behaviour". Antarctic Science. Cambridge University Press. 19 (1): 55–63. Bibcode:2007AntSc..19...55C. doi:10.1017/S0954102007000089. S2CID   73552304 . Retrieved 7 March 2021.
  5. Kennedy, Martyn; Gray, Russell; Spencer, Hamish. "The Phylogenetic Relationships of the Shags and Cormorants: Can Sequence Data Resolve a Disagreement between Behavior and Morphology?" (PDF). The Phylogenetic Relationships of the Shags and Cormorants: Can Sequence Data Resolve a Disagreement between Behavior and Morphology?. Archived from the original (PDF) on 2016-05-06. Retrieved 7 March 2021.
  6. 1 2 Tremblay, Yann; Cook, Timothée; Cherel, Yves. "Time budget and diving behaviour of chick-rearing Crozet Shags". Time budget and diving behaviour of chick-rearing Crozet Shags. Canadian Journal of Zoology. Retrieved 7 March 2021.