Bounty Shear

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Bounty Shear
Bounty Shear

Bounty Shear

Systematics
Class : Birds (aves)
Order : Suliformes
Family : Cormorants (Phalacrocoracidae)
Genre : Leucocarbo
Type : Bounty Shear
Scientific name
Leucocarbo ranfurlyi
( Ogilvie-Grant , 1901)

The bounty shag ( Leucocarbo ranfurlyi , syn .: Phalacrocorax ranfurlyi , English name: Bounty Island Shag ) is a species of bird from the cormorant family (Phalacrocoracidae) that occurs only on the sub-Antarctic bounty islands . The species itself is monotypical ; that is, there are no other subspecies.

The IUCN classifies the Bounty Shear as endangered ( vulnerable ) because the worldwide population is very low and the distribution area is small. Exceptional events in the distribution area, such as an oil spill, can have very far-reaching effects on the population. The global population is estimated by the IUCN at 620 sexually mature individuals.

Appearance

The bounty shear reaches a height of up to 71 centimeters. The wing length is between 27.2 and 30.0 centimeters. Bounty shags weigh between 2.3 and 2.9 kilograms. Males tend to be slightly larger and heavier than females.

The top of the body and the face are black, the throat and front neck and the underside of the body are white. The feet and legs are flesh-colored. The plumage of the young birds is brownish and does not differ from the plumage of other cigars. However, there is no possibility of confusion in the area of ​​distribution, as the bounty shear is the only species of cormorant that occurs here.

Bounty sharks are nimble on land, they walk in an upright posture and raise their feet noticeably. During the flight the head is stretched out, it is lower than the body axis. There is no possibility of confusion with other species of cormorant, as there are no species of this family on Bountinsel. There are only similarities with the Auckland shard , which occurs only on the Auckland Islands.

Distribution area and habitat

The natural habitat of the bounty shear are rocks and cliffs. The population of the endemic species is considered to be vulnerable (but not directly endangered), although it should be noted on the positive side that its habitat is now under strict nature protection ( UNESCO World Heritage Site ). According to the last estimate, the number of breeding pairs is a good 500.

Reproduction

The reproductive biology of the bounty shear has not yet been very well studied. The bounty shear is a colony breeder. It nests along ledges and on cliffs that are out of the reach of sea lions, penguins, and albatrosses. The nests are about three feet apart. Bounty sharks are territorial, both parent birds defend the immediate nesting area.

The laying time falls between October and November. The clutch comprises two to three eggs. The first hatching chicks have so far been observed on November 17th. Nothing is known about the development of the nestlings.

supporting documents

literature

  • PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds , Volume 1, Ratites to Ducks, Oxford University Press, Oxford 1990, ISBN 0195530683
  • 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

Single receipts

  1. ↑ BirdLife Factsheet on Bounty Scar , accessed December 13, 2010
  2. ↑ Shirihai, p. 202
  3. ↑ Shirihai, p. 202
  4. ^ Higgins, p. 893
  5. ^ Higgins, p. 894
  6. ^ Higgins, p. 895

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