South Polar Skua

The south polar skua, known scientifically as Stercorarius maccormicki, is a robust seabird of the family Stercorariidae. It is a large species, though not the largest among its kin, with a body length of approximately 53 cm (21 in). The plumage of adults is predominantly greyish brown on the upper parts, while the head and underparts may vary from whitish to straw-brown, depending on the morph. This contrast is a key feature for identification. Juveniles and the adult dark morphs present a more challenging identification task, requiring attention to subtler traits such as the colder brown plumage and the blue base of the bill.

Identification Tips

In the field, the south polar skua can be recognized by its considerable size, barrel chest, and the white wing flashes that are visible even from afar. Its flight is characterized by directness and power. When compared to its Northern Hemisphere relatives—the Arctic, pomarine, and long-tailed skuas—identification is relatively straightforward. However, distinguishing it from the great skua and other large Southern Hemisphere skuas can be more complex, especially for sightings in the eastern North Atlantic where records are scarce and often questioned.

Habitat

The south polar skua breeds on the Antarctic coasts, where it is well-adapted to the harsh conditions.

Distribution

This migratory bird winters at sea, traversing the Pacific, Indian, and Atlantic Oceans. It has been observed as far as the Geographic South Pole, and in the eastern North Atlantic, its presence is generally replaced by that of the great skua.

Behaviour

The south polar skua exhibits typical skua behavior, boldly flying at the head of any intruder, human or otherwise, that ventures too close to its nest.

Diet and Feeding

The diet of the south polar skua is predominantly piscivorous, with fish often procured through kleptoparasitism—stealing from gulls, terns, and even gannets. It also consumes other birds, rabbits, and carrion. This bird employs less agility and more brute force than its smaller relatives when pursuing prey, maintaining its piratical feeding strategy throughout the year.

Conservation status

The south polar skua is currently classified as Least Concern on the IUCN Red List, indicating that it does not face immediate threats to its survival on a global scale.