Antarctica Skua

Catharacta maccormicki

 The South Polarskua (Stercorarius maccormicki, Syn .: Catharacta maccormicki), also called Antarctic skua, is a species of bird from the sku family (Stercorariidae).

The species reaches a length of 50 to 55 cm, a weight of 900 to 1600 g and a wingspan of 130 to 140 cm. There are two morphs, one light and one dark. The light has a light golden brown to smoky gray body while the back, wings and tail are dark brown. The dark morph is predominantly dark brown in color and can therefore easily be confused with the great skua (Stercorarius skua) or the subantarctic skua (S. antarcticus). The birds become lighter with age and the plumage of adults becomes lighter during the breeding season. The pale morph dominates in the Ross Sea area, while the dark one is more common in the Antarctic Peninsula. In all regions, males in breeding pairs are almost always darker than their larger females. Compared to other skuas, the southern polar skua has a slimmer body, narrower wings, a smaller head, and a narrower beak.

The Südpolarskua spends the southern summer on the coasts of Antarctica, particularly often on the Ross Sea. The breeding season begins in November. The birds are territorial and breed in loose colonies on snow-free areas, often in the vicinity of breeding colonies of penguins, diving petrels or southern petrels. The clutch, which usually consists of two, more rarely one egg, is placed in an unpadded nest pit on the floor and incubated for 28 to 31 days until the young hatch. The young birds, which are initially equipped with light downy plumage, leave the nest after one to two days and fledge between 36 and 45 days. If there are two fledglings, the older usually kills the younger. South Polarskuas become sexually mature at the age of 6.

They leave their breeding grounds in March, move over the equator to the northern hemisphere and spend the Antarctic winter over the open sea off the coasts of Alaska and Greenland. Because it is easily confused with the great sku, it is uncertain whether it occurs in other areas of the North Atlantic apart from Greenland. Crossing South Polarskuas have already been sighted in the northern Indian Ocean, over the Red Sea, near the Seychelles, on the coast of West Africa, on the Caribbean coast of Columbia, east of Japan and off the coast of British Columbia. From October to November the birds return to Antarctica to breed.

Skua Baby (Source Wikipedia (Germany))

In the breeding season, the South Polarskua feeds on fish and krill, the eggs and juveniles of penguins, diving petrels and petrels, carrion, the placentas of seals and near Antarctic stations also kitchen waste. What they eat in the southern winter while they are in the northern hemisphere has not yet been studied in detail. However, it is assumed that their food will then mainly consist of fish, supplemented by carcasses.

The southern polar skua is considered safe. For the year 2009 a population of 6,000 to 15,000 adult individuals was assumed. However, the population fluctuates strongly, depending on the breeding success or the food supply, and can go up or down in different regions.