Skua

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Skuas

Pomarine Skua

Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Charadriiformes
Family:	Stercorariidae Gray, 1871
Genus:	Stercorarius Brisson, 1760

For other uses: see Skua (disambiguation).

Skuas are seabirds in the family Stercorariidae. The three smaller skuas are called jaegers in North America.

The name skua comes from Faroese skúgvur IPA: [ˈskɪkvʊɹ] (Stercorarius skua), and the island of Skúvoy is renowned for its colony of that bird. Jaeger is derived from the German word Jäger, meaning hunter.

Skuas nest on the ground in temperate and Arctic regions and are long-distance migrants.

Outside the breeding season they take fish, offal and carrion. Many are partial kleptoparasites, chasing gulls, terns and other seabirds to steal their catches; the larger species also regularly kill and eat adult birds, up to the size of Great Black-backed Gulls. On the breeding grounds they commonly eat lemmings, and the eggs and young of other birds.

Two skuas and a giant petrel are fighting over a dead Antarctic fur seal

They are in general medium to large birds, typically with grey or brown plumage, often with white markings on the wings. They have longish bills with a hooked tip, and webbed feet with sharp claws. They look like large dark gulls, but have a fleshy cere above the upper mandible. They are strong, acrobatic fliers.

Skuas are related to gulls, waders, auks and skimmers. In the three smaller species (all Holarctic), breeding adults have the two central tail feathers obviously elongated and at least some adults have white on the underparts and pale yellow on the neck, characteristics that the larger species (all native to the Southern Hemisphere except for the Great Skua) do not share. Therefore the skuas are often split into two genera with only the smaller species retained in Stercorarius, and the large species placed in Catharacta. However, there is no genetic basis for this separation^{[citation needed]}. The Pomarine and Great Skuas' mitochondrial DNA (which is inherited from the mother only) is in fact more closely related to each other than it is to either Arctic or Long-tailed Skuas, or to the Southern Hemisphere species^{[citation needed]}. Thus, hybridization must have played a considerable role in the evolution of the diversity of Northern Hemisphere skuas.