Also known as McCormick’s Skua

Latin name: Catharacta maccormicki

South Polar Skua (Photo © Samuel Blanc)

South Polar Skua (Photo © Samuel Blanc)

Population: South Polar skuas have a large global population estimated to be 10,000-20,000 individuals.

Conservation Status: Least Concern (IUCN, 2008)

Where found: South Polar Skuas are circumpolar and abundant, mainly around the continent and the peninsula. South Polar Skuas range far over the polar ice. While adolescent birds may disperse as far as the North Pacific and Atlantic Oceans, the adults remain closer to the breeding grounds through the austral winter.

Wingspan: 126-160 cm

Length: 50-55 cm

Weight: 0.6 to 1.69 kg

Mating/Breeding: South Polar Skuas become sexually mature at 5 years old. Much attached to traditional nesting sites, the South Polar Skuas return to the breeding places, often close by bird cliffs or penguin rookeries, in late October and November. The nest is anything from an unlined scrape to a saucer of grasses, lichens and moss. It is often situated in solitary splendour on a high vantage point overlooking a substantial territory in the style of the eagle. South Polar Skuas return to the same nest site year after year and are faithful to a long-term mate, normally paring for life.

The clutch size is largely dependent on the availability of food. In a good season, when there is plenty of krill, there will be two full-sized eggs; otherwise the second egg is likely to be smaller or not laid at all. Eggs may be laid any time between late November to mid-February, again depending on food potential. Both sexes share the incubation period of approximately 30 days. The chicks are brooded by the males. Fledging takes 57 days and is achieved sometime between late February and early April.

Hunting Habits: The South Polar Skuas display piratical behaviour, pursuing shags and terns in flight, grabbing wings or tails and forcing them to disgorge their catch. The South Polar Skuas are less dependent on piracy and less proficient at taking penguin chicks than the Antarctic skua. The South Polar Skuas  may take Wilson’s storm-petrels in flight.

Feed on: As birds of prey and kleptoparasites, the South Polar Skuas are opportunistic feeders, but sea-fish and krill are a major part of their prey. Their main fish prey is the Antarctic herring Pleurogramma antarcticum, which itself feeds on krill. The South Polar Skuas are enthusiastic predators on penguin, shag and tern colonies.

Threats: Not globally threatened.

Colour/Looks: Smaller than the Antarctic skua and slightly more agile in flight, the South Polar skua is the greyest of the Catharacta skuas. Even so, there is usually a clear contrast between their lighter nape and their darker back. South Polar Skuas occur in pale, medium and dark colour forms.

Interesting Trivia:

  • Herbert Ponting, photographer on Scott’s British Antarctic Expedition of 1910-12, called skuas “the Buccaneers of the South”.
  • The South Polar Skuas is named after the naval surgeon Robert McCormick, who collected the type specimen.
  • The South Polar Skuas are very aggressive in defence of the nest and young, not hesitating to attack a man, beating him about the face with wings or feet, or ripping his scalp in a power-dive.
  • Within just a few hours of hatching, South Polar Skua chicks are able to walk on their own around the territory.
  • In the film Happy Feet, young Emperor Penguin Mumble is beset by 4 South Polar Skuas that have mobster accents, the leader of which bores everyone with his ‘alien abduction’.

More info:

  • Hadoram Shirihai, A complete guide to Antarctic wildlife (2002)
  • David McGonigal & Lynn Woodworth, Antarctica and the Arctic. The complete encyclopedia (2001)
  • Tony Soper, Antarctica. A guide to the wildlife (2000)

Photos:

For more photos by Samuel Blanc, click here