Skua

Skua, common name for members of a bird genus of the gull family; in Britain the name also applies to the birds called jaegers in the Americas. The number of skua species is uncertain; there are five kinds, two or more of which may be the same species. All are large, brown, gull-like birds, fiercely predatory, 53 to 58 cm (21 to 23 in) long, with powerful hooked bills. Skuas feed on fish, small rodents, and the eggs and young of other birds. They commonly attack slower and weaker seabirds such as gulls and terns in mid-air, forcing them to give up whatever food they have in their bills, or even forcing them to disgorge what they have swallowed.

The Arctic skua, great skua, pomarine skua, and long-tailed skua nest in the northern hemisphere, in western Arctic Eurasia, spending the entire non-breeding season at sea as far south as northern South America. The pomarine skua is about 55 cm (22 in) long and its elongated central tail feathers are broad and twisted. Like its smaller relative the Arctic skua (45 cm/18 in), it has light and dark colour phases. In the light phase the back is brown, the cap black, the cheeks yellowish, and the underparts mostly white; dark-phase birds are dark brown all over. The Arctic skua has relatively short, sharply pointed central tail feathers. The long-tailed skua may reach 58 cm (23 in), but as much as 25 cm (10 in) of this length represents its greatly elongated central tail feathers. In this species the dark colour phase is very rare. The other skuas nest on coasts and islands from southern South America to Antarctica.

Scientific classification: Large skuas make up the genus Catharacta of the family Laridae, order Charadriiformes. In Britain the name is also applied to birds classified in the genus Stercorarius. The Arctic skua is classified as Stercorarius parasiticus, the great skua as Catharacta skua, the pomarine skua as Stercorarius pomarinus, and the long-tailed skua as Stercorarius longicaudus.