Kaiserscharbe (Macquariescharbe)

Bestimmung

The Macquarie shag has largely black upperparts and white underparts. The upper cheeks and ear-coverts are black; there are white bars on the wings, a black, recurved crest over the forehead, and pink feet. A breeding adult has a pair of orange caruncles above the base of the bill in front of the eyes, orange-brown facial skin at the base of the lower mandible, as well as blue eye-rings. It is about 75 cm in length, with a wingspan of 110 cm and a weight of 2.5–3.5 kg.

Taxonomie

The Macquarie shag is one of the blue-eyed shags, sometimes placed in the genera Leucocarbo or Notocarbo. Others place it in the genus Phalacrocorax. It is now usually considered to be a full species.

Wissenschaftlicher Name

Leucocarbo atriceps purpurascens

Autorität

(Brandt, JF, 1837)

Ordnung

Suliformes

Familie

Phalacrocoracidae

Gattung

Leucocarbo

Verbreitung und Lebensraum

The Macquarie shag is restricted to subantarctic Macquarie Island and the nearby Bishop and Clerk Islets, part of the Macquarie group, 33 km to the south. Apart from breeding and roosting, its habitat is marine.

Verhalten

Macquarie shags are gregarious, roosting in groups of from a few birds up to several hundred.<p>The birds are present all year round at Macquarie Island, where they breed annually in small to large colonies on bare rocky shores and stacks. Nest-building takes place from June. Nests are truncated cones, 20–30 cm in height, built of vegetation, guano and mud. The clutch of two or three eggs is laid between mid-September and January, mainly in late September and early November, with most eggs hatching by late December. Most chicks are independent of their parents by mid-February.<p>The birds forage locally in shallow coastal waters, with the diet consisting primarily of benthic fish. Flocks may feed together.

Schutzstatus

Der Bestand der Macquariescharbe wurde im Jahr 2000 auf etwa 760 Brutpaare geschätzt, darunter 100 Paare auf den Bishop-and-Clerk-Inseln. Bei einer späteren Erhebung im Oktober 2003 wurden auf der Macquarieinsel selbst 472 brütende Paare in elf Kolonien gezählt, was auf einen Rückgang von 30 % hindeutet.<p>Das Taxon wird nach dem australischen Environment Protection and Biodiversity Conservation Act von 1999 als gefährdet geführt, weil sein Bestand klein und räumlich begrenzt ist und sein Bruterfolg je nach Witterung und Nahrungsangebot schwankt. Weitere Gefahren sind die Erbeutung von Nestlingen durch Subantarktikskuas und Hausratten.