General
Arctic Skua: Large, gull-like bird with pointed wings, and pointed, projecting central tail fathers. Black cap, dark grey upperparts, buff nape, and white underparts except for dark vent. Bill dark gray with black tip, legs black. Sexes similar but juveniles are very different from adults and are dark or rusty coloured with fine streaking on head, fine black and rusty barring on body, can show whitish on rump, and have blunted central tail feathers.
Range and Habitat
Arctic Skua: Migrant breeder found in coastal moorlands in north Scotland, and Shetland and Orkney islands during summer breeding season. On summer passage can be found at coasts especially near tern colonies. Often visible flying over water, only comes to land to breed. Winters on southern oceans.
Breeding and Nesting
Arctic Skua: Monogamous, with pairs demonstrating site fidelity by returning to the same nesting territory year after year. Death of a mate may result in experienced breeders deferring breeding. Eggs are incubated for 25-28 days, typically by both sexes. Fledglings leave nest after 25 to 30 days.
Foraging and Feeding
Arctic Skua: Feeds on birds, small mammals, and insects during the summer. In winter feeds mostly on fish, also on eggs and young birds. Well-known as an avian pirate that will readily harass other birds and steal recently-caught fish.
Vocalisation
Arctic Skua: Usually silent; on breeding grounds utters a series of repeated two-syllable notes and a variety of mewing sounds.
Similar Species
Arctic Skua: The Pomarine Skua is larger and bulkier, has a heavier body, deeper belly, and stout neck. The Long-tailed Skua is also smaller with slimmer wings, elongated rear, longer legs, and shorter bill.