Rock shard
| Rock shard | ||||||||||
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Rock shark ( Phalacrocorax magellanicus ) |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Phalacrocorax magellanicus | ||||||||||
| ( Gmelin , 1789) |
The rock shark ( Phalacrocorax magellanicus ) is a medium-sized, monotypical member of the cormorant family . The species occurs exclusively in the south of South America .
The stock situation of the rock shag was classified in the IUCN Red List of Threatened Species in 2016 as “ Least Concern (LC) ”, as the range of this cormorant species is very large. The population trend is not known with sufficient accuracy, but there is no reason to assume a significant population decline. The global population is estimated at 96,000 to 180,000 sexually mature individuals.
Appearance
The rock shark reaches a body length between 66 and 71 centimeters. The wing length is 23.3 to 25.8 centimeters. Males tend to be slightly larger than the females. The rock shag is not to be confused with any other species within its range.
The plumage is greenish-black on the upper side, the head and neck are black in summer, in winter the plumage on the chin, throat and front neck is white. The featherless skin on the face and throat is red, the feet are flesh-colored. The beak is black and sharply hooked at the tip. During the breeding season, the rock shag wears long white feathers on its head and neck and some white feathers on its back and flanks. The plumage of non-breeding birds is a little more dull and brown.
Young birds are initially almost completely dark-brown, with white plumage only on the belly. Their bare facial skin is still black. Their legs are brownish.
Distribution area
The rock shag is common on the western coast of South America north to the island of Chiloé and on the Falkland Islands . The main areas of distribution include the coast of Tierra del Fuego and the Magellan Beach . The rock shag is a widespread species on the Falkland Islands. During the winter months, the rock shags from South America migrate to northeast Argentina and Uruguay. The population in the Falkland Islands are resident birds.
Way of life
Rock shags eat small fish, crustaceans and cephalopods. They look for their food in relatively shallow water and prefer places near the coast where the sea floor is densely overgrown with kelp. They start their dive with a forward jump, in which the body initially emerges far out of the water. They go looking for food individually or in pairs. On the other hand, they are colony breeders and also seek the company of their own species while resting. In the breeding colonies, they are occasionally associated with the blue-eyed cochlea. The nests are made of grass and seaweed that has washed ashore. In the Falkland Islands, nests are usually found on the ledges of steep cliffs at a height of at least six meters above sea level. Colony sizes range from six to several hundred pairs, although single breeding pairs are occasionally observed. The clutch comprises two to five greenish-white eggs.
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
Individual evidence
- ↑ Leucocarbo magellanicus in the endangered Red List species the IUCN 2016 Posted by: BirdLife International, 2016. Accessed November 18, 2017th
- ↑ BirdLife Factsheet on Felsenscharbe , accessed December 13, 2010
- ↑ Shirihai, p. 194
- ↑ Shirihai, p. 192
- ↑ Wood, p. 65
- ↑ Wood, p. 64
Web links
- Videos, photos and sound recordings of Phalacrocorax magellanicus in the Internet Bird Collection
- Leucocarbo magellanicus inthe IUCN Red List of Threatened Species 2013.1. Listed by: BirdLife International, 2012. Retrieved October 26, 2013.