Blue-eye shag
| Blue-eye shag | ||||||||
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Blue-eye shags in southern Argentina |
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| Systematics | ||||||||
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| Scientific name | ||||||||
| Leucocarbo atriceps | ||||||||
| ( King , 1828) |
The blue-eyed shag ( Leucocarbo atriceps , Syn . : Phalacrocorax atriceps ), also called Antarctic cormorant , is a very large species from the cormorant family . It occurs exclusively in the south of South America. A distinction is made between several subspecies, but the exact number of subspecies is disputed in the literature.
The IUCN classifies the blue-eyed shag as harmless ( least concern ), as the range of this species is very large. The exact population trend is not known, but there is no evidence that population numbers are declining significantly. The worldwide population is estimated at 340,000 to 1.4 million sexually mature individuals.
Appearance
When fully grown, the blue-eye cochlea reaches a body length of 69 to 74 cm and a wingspan of 112 cm. It then weighs between 2.5 and 3.5 kilograms. Males tend to be slightly larger and heavier than females, otherwise there is no noticeable sexual dimorphism .
The plumage is white on the throat, cheek, front neck and underside, whereas it is glossy black on the top of the head, on the back of the neck and on the upper side. At the back of the head, adult blue-eye shags have elongated feathers during the breeding season, which can be erected. It is named after a bright blue eye ring. The featherless skin of the face is also bluish, while the feet are flesh-colored and the webbed feet are black. Young birds are feathered brown and white. They still lack the bluish eye ring, the bare facial skin is duller and the beak is duller in color.
distribution
The blue-eyed shag is native to the Antarctic peninsula and the islands off the Antarctic . It breeds on the South Orkney Islands , the South Shetland Islands , off Cape Horn and Patagonia, as well as on Heard near the sea in colonies consisting of a few dozen pairs. In the Falkland Islands , the blue-eyed shag is a widespread breeding bird on the coast.
There are different subspecies of this species of cormorant, all of which differ slightly in color and drawing.
Way of life
Blue-eyed shags mostly eat crustaceans and small fish, which they hunt while diving. They occasionally forage for food some distance from the coast. They are colony breeders and also sociable birds during resting times and foraging for food. They often breed near rockhopper penguins and black- browed albatrosses . The nest is built from algae, mud and grass. The actual nesting trough is covered with grass. The clutch consists of two to four eggs. These are pale green-blue. The incubation period is 28 days.
supporting documents
literature
- Hadoram Shirihai: A Complete Guide to Antarctic Wildlife - The Birds and Marine Mammals of the Antarctic Continent and Southern Ocean , Alula Press, Degerby 2002, ISBN 951-98947-0-5
- Robin and Anne Woods: Atlas of Breeding Birds of the Falkland Islands , Anthony Nelson, Shorpshire 1997, ISBN 0904614-60-3
Web links
- Videos, photos and sound recordings of Phalacrocorax atriceps in the Internet Bird Collection
- Leucocarbo atriceps inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2012. Retrieved December 30, 2013.
Single receipts
- ↑ Shirihai, p. 195
- ↑ BirdLife Factsheet on the Blue Eye Shag , accessed on December 13, 2010
- ↑ Wkood, p 66