Kerguelen shag | |
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Immature (top), adult (left), and chick | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Suliformes |
Family: | Phalacrocoracidae |
Genus: | Leucocarbo |
Species: | L. verrucosus |
Binomial name | |
Leucocarbo verrucosus (Cabanis, 1875) | |
Synonyms | |
Phalacrocorax verrucosus |
The Kerguelen shag (Leucocarbo verrucosus) 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. [2]
This species nests on the coast of Grande Terre (the main island of the archipelago), on offshore islands, and on islands in the Golfe du Morbihan. It forages at sea throughout the archipelago, usually within 6 km (3.7 mi) of shore and especially in bays and inlets, though immatures have been seen rarely as far as 80 km (50 mi). [2] Reports from Heard Island and western Australia may be of ship-assisted birds. [3]
In the austral summer it feeds among kelp, sometimes at the bottom. [2]
The Kerguelen shag is 65 cm (25.5 in) long with a wingspan of 110 cm (43.5 in), making it the smallest blue-eyed shag. [3] The adult's upperparts, tail, and thighs are metallic greenish black; the underbody to the throat is white; and the wing linings are brown. Some individuals have white patches on the back and wings. The head and the back of the neck are deep blue or purple, except that a black cap reaches below the eye to the chin and ear coverts. The face and throat pouch are dark brown, ornamented with yellow-orange tubercles. The bill is horn-colored or brown; the eyes are hazel. The legs and feet vary from dark brown to dark-blotched bright pink. Breeding adults have a little black erectile crest on the forehead, yellow or orange caruncles (large warts) above the base of the bill, and a bright blue ring around the eye. After the breeding season, the plumage fades, the eye-ring becomes lead-blue, and the caruncles become smaller and duller-colored. [2] [3]
Juveniles are dark brown with varying amounts of white underneath and brown iris, bill, and feet. They have no caruncles, and their eye-rings are lead-blue. They acquire adult plumage gradually. [2] [3]
Unlike many cormorants, this species does not spread its wings when it is perched. [3]
Kerguelen shags presumably eat mostly fish and such invertebrates as echinoderms, crustaceans, and polychaete worms. In summer they mostly forage alone, but from May to October they form linear flocks of several hundred, diving and surfacing sequentially down the line. [2]
This species breeds in colonies, usually of 3 to 30 pairs but occasionally up to 400. Colonies may be near those of southern rockhopper penguins. There is a period of nest-building and displaying in late March and early April—an unusual time for a subantarctic cormorant. Advertising males display by throwing the head back till the nape touches the tail. Nests are cones of seaweed, twigs, and grass held together with mud and guano, up to 1 meter tall and 33 cm across, with a cup averaging 20 cm across and 8 cm deep. Nests that survive may be reused, perhaps not by the same pair. Breeding activity starts as early as September, but laying usually starts at some point from late October to late November and lasts till mid January; the times vary considerably among colonies. The clutch comprises two to four eggs, about 6.2 cm long and 3.9 cm wide. The second egg is laid 2 or 3 days after the first. Both parents incubate for an average of 29 days. Both protect the chicks from predation by skuas, gulls, and sheathbills, which nevertheless take some chicks. Chicks hatch black with a pink throat and develop blackish-brown down with greyish-white tufts. Other aspects of reproductive behavior and success are unknown. [2]
The population was about 6,000 to 7,000 pairs in 1984–1987. [2] Interactions with human beings and introduced mammals do not appear to be damaging the population. [3]
This species has been placed in genera Halieus, Hypoleucos, Notocarbo, [2] and Leucocarbo. [4] Others place it in the genus Phalacrocorax. It has been considered conspecific with some other blue-eyed shags under the name imperial shag. [2] [5] Here it is considered a separate species following the Handbook of the Birds of the World [6] and other authorities [2] [3] [4] [7]
It has been suggested that Heard shags may visit the Kerguelens and that Kerguelen shags with white wing or back patches are the result of hybridization. [2] [3]
The epithet verrucosus means "full of warts", referring to the facial ornaments. [8]
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, Thailand, Myanmar, Singapore, Brunei, 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.
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 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.
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 extending 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 eye, small head with a sloping forehead and a long narrow bill ending in a hooked tip.
The Otago shag,, together with the Foveaux shag formerly known as the Stewart Island shag and in its dark phase as the bronze shag, is a species of shag now found only in coastal Otago, New Zealand.
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 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 New Zealand king shag, also known as the rough-faced shag, king shag or kawau, 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.
Leucocarbo is a genus of birds in the family Phalacrocoracidae with the members commonly known as blue-eyed shags. This is a group of closely related cormorant taxa. Many have a blue, purple or red ring around the eye ; other shared features are white underparts and pink feet.
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 Bounty shag, also known as the Bounty Island shag, is a species of cormorant of the family Phalacrocoracidae. They are found only on the tiny and remote Subantarctic Bounty Islands, 670 km southeast of New Zealand. Its natural habitats are open seas and rocky shores. In 2005 618 individuals were counted and the population seems to have remained stable since.
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 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.
The Foveaux shag, together with the Otago shag formerly known as the Stewart Island shag and in its dark phase as the bronze shag, is a species of shag endemic to Stewart Island/Rakiura and Foveaux Strait, from which it takes its name.