Great cormorant

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Great cormorant
Phalacrocorax carbo Vic.jpg
In Victoria, Australia
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Suliformes
Family: Phalacrocoracidae
Genus: Phalacrocorax
Species:
P. carbo
Binomial name
Phalacrocorax carbo
PhalacrocoraxCarbo.png
Range of P. carbo
  Breeding
  Resident
  Passage
  Non-breeding
Synonyms

Pelecanus carboLinnaeus, 1758

Adult great cormorant in breeding plumage. Texel, Netherlands (2010)

The great cormorant (Phalacrocorax carbo), 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. [2] The genus name is Latinised Ancient Greek, from φαλακρός (phalakros, "bald") and κόραξ (korax, "raven"), and carbo is Latin for "charcoal". [3]

Contents

It breeds in much of the Old World, Australia, and the Atlantic coast of North America.

Taxonomy and etymology

The 80–100 cm (30–40 in) long white-breasted cormorant P. c. lucidus, found in sub-Saharan Africa, has a white neck and breast. It is often treated as a full species, Phalacrocorax lucidus (e.g. Sibley & Monroe 1990, Sinclair, Hockey & Tarboton 2002).

In addition to the Australasian and African forms, other geographically distinct subspecies are recognised, including P. c. sinensis (western Europe to east Asia), P. c. maroccanus (north-western Africa), and P. c. hanedae (Japan). [4]

Some authors[ who? ] treat all these as allospecies of a P. carbo superspecies group.[ citation needed ]

In New Zealand, the subspecies P. c. novaehollandiae is known as the black shag or by its Māori name: "kawau". [5] The syntype is in the collection of the Museum of New Zealand Te Papa Tongarewa. [6]

Description

The great cormorant is a large black bird, but there is a wide variation in size in the species' wide range. Weight is reported to vary from 1.5 kg (3 lb 5 oz) [7] to 5.3 kg (11 lb 11 oz). [8] Males are typically larger and heavier than females, with the nominate race (P. c. carbo) averaging about 10% larger in linear measurements than the smallest race in Europe (P. c. sinensis). [9] The lightest average weights cited are in Germany (P. c. sinensis), where 36 males averaged 2.28 kg (5 lb 1⁄2 oz) and 17 females averaged 1.94 kg (4 lb 4+1⁄2 oz). [10] The highest come from Prince Edward Island in Canada (P. c. carbo), where 11 males averaged 3.68 kg (8 lb 2 oz) and 11 females averaged 2.94 kg (6 lb 7+1⁄2 oz). [11] [12] Length can vary from 70 to 102 cm (27+1⁄2 to 40 in) and wingspan from 121 to 160 cm (47+1⁄2 to 63 in). [12] [13] They are tied as the second largest extant species of cormorant after the flightless cormorant, with the Japanese cormorant averaging at a similar size. In bulk if not in linear dimensions, the blue-eyed shag species complex of the Southern Oceans are scarcely smaller at average. [10] It has a longish tail and yellow throat-patch. Adults have white patches on the thighs and on the throat in the breeding season. In European waters it can be distinguished from the common shag by its larger size, heavier build, thicker bill, lack of a crest and plumage without any green tinge. In eastern North America, it is similarly larger and bulkier than double-crested cormorant, and the latter species has more yellow on the throat and bill and lack the white thigh patches frequently seen on great cormorants. Great cormorants are mostly silent, but they make various guttural noises at their breeding colonies. [4]

Variations

A very rare variation of the great cormorant is caused by albinism. The Phalacrocorax carbo albino suffers from poor eyesight and/or hearing, thus it rarely manages to survive in the wild.[ citation needed ]

Distribution

This is a very common and widespread bird species. It feeds on the sea, in estuaries, and on freshwater lakes and rivers. Northern birds migrate south and winter along any coast that is well-supplied with fish.[ citation needed ]

In Serbia, the cormorant lives in Vojvodina. However, after 1945 many artificial lakes were formed in Serbia; some of them became potential habitats for cormorants. Currently, on the Lake Ćelije, formed in 1980, there is a resident colony of cormorants, who nest there and are present throughout the year, except January–February 1985 and February 2012 when the lake surface was completely frozen.[ citation needed ]

The type subspecies, P. c. carbo, is found mainly in Atlantic waters and nearby inland areas: on western European coasts and east across the Palearctic to Siberia and to North Africa, the Faroe Islands, Iceland and Greenland; and on the eastern seaboard of North America. The subspecies P. c. novaehollandiae is found in Australian waters. [5]

Behaviour

Diving in Dambovita River, Bucharest GreatCormorantDiving.jpg
Diving in Dambovita River, Bucharest
Great cormorant with bronze featherback at Keoladeo Ghana National Park, Bharatpur Greater cormorant in Action 02.jpg
Great cormorant with bronze featherback at Keoladeo Ghana National Park, Bharatpur
Great cormorant trying to swallow bronze featherback at Keoladeo Ghana National Park, Bharatpur Greater cormorant in Action 01.jpg
Great cormorant trying to swallow bronze featherback at Keoladeo Ghana National Park, Bharatpur
Great cormorant at Ponnani, Malappuram, Kerala, India Great cormorant (Phalacrocorax carbo),.jpg
Great cormorant at Ponnani, Malappuram, Kerala, India
A great cormorant dries its wings in the sunset in Ystad. Storskarv - (Phalacrocorax carbo) - Ystad-2023.jpg
A great cormorant dries its wings in the sunset in Ystad.

Breeding

The great cormorant often nests in colonies near wetlands, rivers, and sheltered inshore waters. Pairs will use the same nest site to breed year after year. It builds its nest, which is made from sticks, in trees, on the ledges of cliffs, and on the ground on rocky islands that are free of predators. [14]

This cormorant lays a clutch of three to five eggs that measure 63 by 41 millimetres (2+1⁄2 by 1+5⁄8 in) on average. The eggs are a pale blue or green, and sometimes have a white chalky layer covering them. These eggs are incubated for a period of about 28 to 31 days. [14]

Feeding

The great cormorant feeds on fish caught through diving. [14] This bird feeds primarily on wrasses, but it also takes sand smelt, flathead and common soles. [15] The average weight of fish taken by great cormorants increased with decreasing air and water temperature. Cormorants consume all fish of appropriate size that they are able to catch in summer and noticeably select for larger, mostly torpedo-shaped fish in winter. Thus, the winter elevation of foraging efficiency described for cormorants by various researchers is due to capturing larger fish not due to capturing more fish. [16] In some freshwater systems, the losses of fish due to overwintering great cormorants were estimated to be up to 80 kg per ha each year (e.g. Vltava River, Czech Republic). [17]

This cormorant forages by diving and capturing its prey in its beak. [14] The duration of its dives is around 28 seconds, with the bird diving to depths of about 5.8 metres (19 ft 0 in). About 60% of dives are to the benthic zone and about 10% are to the pelagic zone, with the rest of the dives being to zones in between the two. [15] Studies suggest that their hearing has evolved for underwater usage, possibly aiding their detection of fish. [18] These adaptations also have a cost on their hearing ability in air which is of lowered sensitivity. [19]

Relationships with humans

Many fishermen see in the great cormorant a competitor for fish. Because of this, it was hunted nearly to extinction in the past. Due to conservation efforts, its numbers increased. At the moment, there are about 1.2 million birds in Europe (based on winter counts; late summer counts would show higher numbers). [20] Increasing populations have once again brought the cormorant into conflict with fisheries. [21] [22] For example, in Britain, where inland breeding was once uncommon, there are now increasing numbers of birds breeding inland, and many inland fish farms and fisheries now claim to be suffering high losses due to these birds. In the UK each year, some licences are issued to cull specified numbers of cormorants in order to help reduce predation; it is, however, still illegal to kill a bird without such a licence. [23]

Cormorant fishing is practised in China, Japan, and elsewhere around the globe. In this practice, fishermen tie a line around the throats of cormorants, tight enough to prevent swallowing the larger fish they catch, and deploy them from small boats. The cormorants catch fish without being able to fully swallow them, and the fishermen are able to retrieve the fish simply by forcing open the cormorants' mouths, apparently engaging the regurgitation reflex. [24]

In Norway, the cormorant is a traditional game bird. Each year approximately 10,000 cormorants are shot to be eaten. [25] In North Norway, cormorants are traditionally seen as semi-sacred.[ citation needed ] It is regarded as good luck to have cormorants gather near your village or settlement. An old legend states that for people who die far out at sea, whose bodies are never recovered, spend eternity on the island Utrøst – which can only occasionally be found by mortals. The inhabitants of Utrøst can only visit their homes in the shape of cormorants.[ citation needed ]

Cormorant fishing in Wuzhen Xizha, Zhejiang, China Wuzhen Xizha 2009-01-2.jpg
Cormorant fishing in Wuzhen Xizha, Zhejiang, China

Videos

Related Research Articles

<span class="mw-page-title-main">Cormorant</span> Family of aquatic birds

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.

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

The double-crested cormorant is a member of the cormorant family of water birds. It is found near rivers and lakes and in coastal areas and is widely distributed across North America, from the Aleutian Islands in Alaska down to Florida and Mexico. Measuring 70–90 cm (28–35 in) in length, it is entirely black except for a bare patch of orange-yellow facial skin and some extra plumage that it exhibits in the breeding season when it grows a double crest in which black feathers are mingled with white. Five subspecies are recognized. It mainly eats fish and hunts by swimming and diving. Its feathers, like all cormorants, are not waterproof, and it must dry them out after spending time in the water. Once threatened by the use of DDT, the numbers of this bird have increased markedly in recent years.

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

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.

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

The little pied cormorant, little shag or kawaupaka is a common Australasian waterbird, found around the coasts, islands, estuaries, and inland waters of Australia, New Guinea, New Zealand, Timor-Leste, and Indonesia, and around the islands of the south-western Pacific and the subantarctic. It is a small short-billed cormorant usually black above and white below with a yellow bill and small crest, although a mostly black white-throated form predominates in New Zealand. Three subspecies are recognised. Until recently most authorities referred to this species as Phalacrocorax melanoleucos.

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

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

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".

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

The spotted shag or pārekareka is a species of cormorant endemic to New Zealand. Though originally classified as Phalacrocorax punctatus, it is sufficiently different in appearance from typical members of that genus that for a time it was placed in a separate genus, Stictocarbo, along with a similar species, the Pitt shag. Subsequent genetic studies show that the spotted shag's lineage is nested within the typical shags.

In biology, trinomial nomenclature is the system of names for taxa below the rank of species. These names have three parts. The usage is different in zoology and botany.

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

The Indian cormorant or Indian shag is a member of the cormorant family. It is found mainly along the inland waters of the Indian Subcontinent but extends west to Sind and east to Thailand and Cambodia. It is a gregarious species that can be easily distinguished from the similar sized little cormorant by its blue eyes, small head with a sloping forehead and a long narrow bill ending in a hooked tip.

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

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.

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

The little black cormorant is a member of the cormorant family of seabirds. It is common in smaller rivers and lakes throughout most areas of Australia and northern New Zealand, where it is known as the little black shag. It is around sixty centimetres long, and is all black with blue-green eyes.

<span class="mw-page-title-main">European perch</span> Species of fish

The European perch, also known as the common perch, redfin perch, big-scaled redfin, English perch, Euro perch, Eurasian perch, Eurasian river perch, Hatch, poor man's rockfish or in Anglophone parts of Europe, simply the perch, is a predatory freshwater fish native to Europe and North Asia. It is the type species of the genus Perca.

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

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.

<span class="mw-page-title-main">White-breasted cormorant</span> Member of the cormorant family Phalacrocoracidae from Sub-Saharan Africa

The white-breasted cormorant is much like the widespread great cormorant and if not a regional variant of the same species, is at least very closely related. It is distinguished from other forms of the great cormorant by its white breast and by the fact that subpopulations are freshwater birds. Phalacrocorax lucidus is not to be confused with the smaller and very different endemic South Australian black-faced cormorant, which also is sometimes called the white-breasted cormorant.

<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">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">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">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. ↑ BirdLife International (2019). "Phalacrocorax carbo". IUCN Red List of Threatened Species . 2019: e.T22696792A155523636. doi: 10.2305/IUCN.UK.2018-2.RLTS.T22696792A155523636.en . Retrieved 13 November 2021.
  2. ↑ Ali, S. (1993). The Book of Indian Birds. Bombay: Bombay Natural History Society. ISBN   978-0-19-563731-1.
  3. ↑ Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp.  90, 301. ISBN   978-1-4081-2501-4.
  4. 1 2 Cramp, S; Simmons, K. E. L. (1977). The Birds of the Western Palearctic Volume 1. Ostrich to Ducks. Oxford, UK: Oxford University Press.
  5. 1 2 Heather, Barrie; Robertson, Hugh (2005). The Field guide to the Birds of New Zealand (revised ed.). Viking. ISBN   978-0143020400.
  6. ↑ "Phalacrocorax carbo novaehollandiae; syntype". Collections Online. Museum of New Zealand Te Papa Tongarewa. Retrieved 18 July 2010.
  7. ↑ Ribak, Gal; Weihs, Daniel; Arad, Zeev (2005). "Water retention in the plumage of diving great cormorants Phalacrocorax carbo sinensis". Journal of Avian Biology. 36 (2): 89. doi:10.1111/j.0908-8857.2005.03499.x.
  8. ↑ "Cormorant". The Canadian Encyclopedia. Retrieved 21 August 2012.
  9. ↑ Koffijberg, K.; Van Eerden, M.R. (1995). "Sexual dimorphism in the cormorant Phalacrocorax carbo sinensis: possible implications for differences in structural size" (PDF). Ardea. 83: 37–46.
  10. 1 2 Dunning Jr., John B., ed. (1992). CRC Handbook of Avian Body Masses. CRC Press. ISBN   978-0-8493-4258-5.
  11. ↑ Hogan, G. (1979). Breeding parameters of Great Cormorants (Phalacrocorax carbo) at mixed species colonies on Prince Edward Island, Canada (Master's Thesis). St. Catharines, ON: Brock University. hdl:10464/1789.
  12. 1 2 Hatch, Jeremy J.; Brown, Kevin M.; Hogan, Geoffrey G.; Morris, Ralph D. (2000). Poole, A. (ed.). "Great Cormorant (Phalacrocorax carbo)". The Birds of North America Online. Ithaca: Cornell Lab of Ornithology. doi:10.2173/bna.553.
  13. ↑ Stevenson, Terry; Fanshawe, John (2001). Field Guide to the Birds of East Africa: Kenya, Tanzania, Uganda, Rwanda, Burundi. Elsevier Science. ISBN   978-0-85661-079-0.
  14. 1 2 3 4 Hauber, Mark E. (1 August 2014). The Book of Eggs: A Life-Size Guide to the Eggs of Six Hundred of the World's Bird Species. Chicago: University of Chicago Press. p. 132. ISBN   978-0-226-05781-1.
  15. 1 2 Grémillet, D.; Argentin, G.; Schulte, B.; Culik, B. M. (2008). "Flexible foraging techniques in breeding cormorants Phalacrocorax carbo and shags Phalacrocorax aristotelis: benthic or pelagic feeding?". Ibis. 140 (1): 113–119. doi:10.1111/j.1474-919X.1998.tb04547.x. ISSN   0019-1019.
  16. ↑ Čech M., Čech P., Kubečka J., Prchalová M., Draštík V. (2008). "Size selectivity in summer and winter diets of great cormorant (Phalacrocorax carbo): Does it reflect season-dependent difference in foraging efficiency?". Waterbirds. 31 (3): 438–447. doi:10.1675/1524-4695-31.3.438. JSTOR   25148353. S2CID   84199917.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ↑ Čech M., Vejřík L. (2011). "Winter diet of great cormorant (Phalacrocorax carbo) on the River Vltava: estimate of size and species composition and potential for fish stock losses". Folia Zoologica. 60 (2): 129–142. doi:10.25225/fozo.v60.i2.a7.2011. S2CID   90464667.
  18. ↑ "Surprising hearing talents in cormorants". ScienceDaily. Retrieved 2020-10-08.
  19. ↑ Larsen, Ole Næsbye; Wahlberg, Magnus; Christensen-Dalsgaard, Jakob (2020-03-15). "Amphibious hearing in a diving bird, the great cormorant ( Phalacrocorax carbo sinensis )". The Journal of Experimental Biology. 223 (6): jeb217265. doi: 10.1242/jeb.217265 . ISSN   0022-0949. PMID   32098879. S2CID   211524892.
  20. ↑ "Cormorants in the western Palearctic, Distribution and numbers on a wider European scale" (PDF). Wetland International Cormorant Research Group. Archived from the original (PDF) on 7 June 2011.
  21. ↑ "Workshop on a European Cormorant management Plan, 20–21 November 2007" (PDF). EIFAC, European Inland Fisheries Advisory Commission.[ permanent dead link ]
  22. ↑ "European Parliament resolution". 4 December 2008. on the adoption of a European Cormorant Management Plan to minimise the increasing impact of cormorants on fish stocks, fishing and aquaculture
  23. ↑ Woolf, Marie (2004-07-28). "Anglers urge cull of cormorants for eating too many fish". The Independent. Archived from the original on December 31, 2014. Retrieved 2014-12-30.
  24. ↑ Larson-Wang, Jessica. "The History Behind the Cormorant Fishermen of Erhai Lake". Culture Trip. Archived from the original on 2020-08-16. Retrieved 2019-08-17.
  25. ↑ "Reducing the conflict between Cormorants and fisheries on a pan-European scale" (PDF). Final Report. REDCAFE. p. 12. Around 10,000 adult Cormorants (of the 'Atlantic' carbo race) are hunted legally as game in Norway outside the breeding season.

Further reading

Separation of carbo and sinensis
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