European shag

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European shag
Shag Phalacrocorax aristotelis.jpg
European shag on a rock
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Suliformes
Family: Phalacrocoracidae
Genus: Gulosus
Montagu, 1813
Species:
G. aristotelis
Binomial name
Gulosus aristotelis
(Linnaeus, 1761)
GulosusAristotelisIUCNver2018 2.png
Range of G. aristotelis
  Breeding
  Non-breeding
Synonyms

Phalacrocorax aristotelis

The European shag or common shag (Gulosus aristotelis) is a species of cormorant. It is the only member of the monotypic genus Gulosus. [2] 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. [3] The scientific genus name derives from the Latin for glutton. The species name aristotelis commemorates the Greek philosopher Aristotle. [4]

Contents

Taxonomy

The European shag was formerly classified within the genus Phalacrocorax , but a 2014 study found it to be significantly more diverged than the clade containing Phalacrocorax and Urile , but basal to the clade containing Nannopterum and Leucocarbo , and thus classified it in its own genus, Gulosus. [5] The IOC followed this classification in 2021. [6] Gulosus is thought to have split from the Nannopterum-Leucocarbo clade between 9.0 - 11.2 million years ago. [5]

Subspecies

There are three subspecies: [7]

The subspecies differ slightly in bill size and the breast and leg colour of young birds. Recent evidence suggests that birds on the Atlantic coast of southwest Europe are distinct from all three, and may be an as-yet undescribed subspecies. [8]

The name shag is also used in the Southern Hemisphere for several additional species of cormorants.

Description

This is a medium-large black bird, 68 to 78 cm (27 to 31 in) long and with a 95-to-110-centimetre (37 to 43 in) wingspan. It has a longish tail and a yellow throat patch. Adults have a small crest in the breeding season. It is distinguished from the great cormorant by its smaller size, lighter build, thinner bill, and, in breeding adults, by the crest and metallic green-tinged sheen on the feathers. Among those differences are that a shag has a lighter, narrower beak, and the juvenile shag has darker underparts. The European shag's tail has 12 feathers, as do the great cormorant's 14 feathers. The green sheen on the feathers results in the alternative name green cormorant sometimes being given to the European shag.

Biology

Shag in flight EuropeanShag.jpg
Shag in flight

It feeds in the sea, and, unlike the great cormorant, is rare inland. It will winter along any coast that is well-supplied with fish. The European shag is one of the deepest divers among the cormorant family. Using depth gauges, European shags recorded diving up to 61 m (200 ft) deep. [9] European shags are preponderantly benthic zone feeders, i.e. they find their prey on the sea bottom. They will eat a wide range of fish but their commonest prey is the sand eel. Shags will travel many kilometres from their roosting sites in order to feed.

European Shag dives to 18 m. for hunting

In UK coastal waters, dive times are typically around 20 to 45 seconds, with a recovery time of around 15 seconds between dives; this is consistent with aerobic diving, i.e. the bird depends on the oxygen in its lungs and dissolved in its bloodstream during the dive. When they dive, they jump out of the water first to give extra impetus to the dive.

It breeds on coasts, nesting on rocky ledges or in crevices or small caves. The nests are untidy heaps of rotting seaweed or twigs cemented together by the bird's own guano. The nesting season is long, beginning in late February but some nests are not started until May or even later. Three eggs are laid. Their chicks hatch without down and so they rely totally on their parents for warmth, often for a period of two months before they can fly. Fledging may occur at any time from early June to late August, exceptionally to mid-October.

Diet

The shag is a pursuit-diving seabird that feeds predominantly in benthic habitats. Due to the relative ease with which diet samples can be collected from this species (regurgitated food or pellets) and the perceived conflict between the Phalacrocoracidae and fisheries, shag diet competition has been the subject of substantial scientific interest. [10] [11] [12] [13] Evidence collected at one colony, the Isle of May, Scotland, between 1985 and 2014, suggests that shag chick diet composition in this population has diversified in response to ocean warming. [14] Shags also feed on fewer sandeel on windy days, presumably due to the strong effect of wind on flight in this species. [15] The year-round diet of full-grown shags at this colony has also changed over the past 3 decades, from sandeel specialists to an increasingly diverse prey base. [16]

Distribution

The European shag can be readily seen among the following locations during the breeding season, between late April and mid-July: Saltee Islands, Ireland; Farne Islands and Isles of Scilly, England; Isle of May, Deerness and Fowlsheugh, Scotland; Runde, Norway; Iceland; Denmark; Faroe Islands; Galicia, Northern Spain; Dalmatia and Istria, Croatia. In April 2017, eight new European shags were born in Monaco. [17]

The largest colony of European shags is in the Cíes Islands, Spain, with 2,500 pairs (25% of the world's population).

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.

<i>Phalacrocorax</i> Genus of birds

Phalacrocorax is a genus of fish-eating birds in the cormorant family Phalacrocoracidae. Members of this genus are also known as the Old World cormorants.

<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">Great cormorant</span> Species of 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".

<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.

<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">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">Cape cormorant</span> Species of bird

The Cape cormorant or Cape shag is a bird endemic to the southwestern coasts of Africa.

<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">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">Chatham shag</span> Species of bird

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.

<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.

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

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.

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

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).

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

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.

<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 (2018). "Gulosus aristotelis". IUCN Red List of Threatened Species . 2018: e.T22696894A133538524. doi: 10.2305/IUCN.UK.2018-2.RLTS.T22696894A133538524.en . Retrieved 19 November 2021.
  2. Kennedy, Martyn; Spencer, Hamish G. (2014-10-01). "Classification of the cormorants of the world". Molecular Phylogenetics and Evolution. 79: 249–257. doi:10.1016/j.ympev.2014.06.020. ISSN   1055-7903. PMID   24994028.
  3. "Annotated List of the Seabirds of the World - Boobies, Cormorants, Frigatebirds and Tropicbirds". www.oceanwanderers.com. Retrieved 8 October 2007.
  4. Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 55, 301. ISBN   978-1-4081-2501-4.
  5. 1 2 Kennedy, Martyn; Spencer, Hamish G. (2014-10-01). "Classification of the cormorants of the world". Molecular Phylogenetics and Evolution. 79: 249–257. doi:10.1016/j.ympev.2014.06.020. ISSN   1055-7903.
  6. "Taxonomic Updates – IOC World Bird List" . Retrieved 2021-07-28.
  7. Gill, Frank; Donsker, David; Rasmussen, Pamela (eds.). "Storks, frigatebirds, boobies, cormorants, darters". IOC World Bird List. Retrieved 30 November 2020.
  8. Yésou, P.; Buchheim, A.; Bermejo, A. (2005). "Which subspecies of Shag occurs in Galicia?" (PDF). British Birds . 98: 369–370.
  9. "species". polaris.nipr.ac.jp. Archived from the original on 2022-08-10. Retrieved 2022-08-10.
  10. Snow, Barbara (1960-10-01). "The Breeding Biology of the Shag Phalacrocorax Aristotelis on the Island of Lundy, Bristol Channel". Ibis. 102 (4): 554–575. doi:10.1111/j.1474-919x.1960.tb07132.x. ISSN   1474-919X.
  11. Barrett, RT; Rov, N; Loen, J; Montevecchi, WA (1990). "Diets of shags Phalacrocorax aristotelis and cormorants P carbo in Norway and possible implications for gadoid stock recruitment" (PDF). Marine Ecology Progress Series. 66: 205–218. Bibcode:1990MEPS...66..205B. doi: 10.3354/meps066205 .
  12. Harris, M. P.; Wanless, S. (1991). "The Importance of the Lesser Sandeel Ammodytes marinus in the Diet of the Shag Phalacrocorax aristotelis". Ornis Scandinavica (Scandinavian Journal of Ornithology). 22 (4): 375–382. doi:10.2307/3676511. JSTOR   3676511.
  13. Cosolo, Mauro; Privileggi, Nicoletta; Cimador, Barbara; Sponza, Stefano (2011-11-01). "Dietary changes of Mediterranean Shags Phalacrocorax aristotelis desmarestii between the breeding and post-breeding seasons in the upper Adriatic Sea". Bird Study. 58 (4): 461–472. doi: 10.1080/00063657.2011.603290 . ISSN   0006-3657. S2CID   59032510.
  14. Howells, RJ; Burthe, SJ; Green, JA; Harris, MP; Newell, MA; Butler, A; Johns, DG; Carnell, EJ; Wanless, S (2017). "From days to decades: short- and long-term variation in environmental conditions affect offspring diet composition of a marine top predator". Marine Ecology Progress Series. 583: 227–242. Bibcode:2017MEPS..583..227H. doi: 10.3354/meps12343 .
  15. Lewis, Sue; Phillips, Richard A.; Burthe, Sarah J.; Wanless, Sarah; Daunt, Francis (2015-11-01). "Contrasting responses of male and female foraging effort to year-round wind conditions". Journal of Animal Ecology. 84 (6): 1490–1496. doi:10.1111/1365-2656.12419. ISSN   1365-2656. PMC   4989534 . PMID   26283625.
  16. Howells, Richard J.; Burthe, Sarah J.; Green, Jonathan A.; Harris, Michael P.; Newell, Mark A.; Butler, Adam; Wanless, Sarah; Daunt, Francis (2018-11-21). "Pronounced long-term trends in year-round diet composition of the European shag Phalacrocorax aristotelis". Marine Biology. 165 (12). doi: 10.1007/s00227-018-3433-9 . ISSN   0025-3162.
  17. Verdi, Laurent (April 12, 2017). "Naissance exceptionnelle à Monaco: huit cormorans huppés ont vu le jour". France 3 Côte d'Azur. Retrieved April 13, 2017.