The pomarine skua breeds in high arctic regions in North America and throughout northern Siberia. It is a large, strong skua; larger than the arctic skua and with broader wings. Pomarine skuas are often seen following ships or flocks of other sea birds such as groups of black-legged kittiwakes.
The pomarine skua is a heavy-set, sturdily built skua. The adults are recognized by their broad, club-shaped, projected central tail-feathers which are twisted at the ends.
This species occurs, like the arctic skua, in two distinct colour phases (along with intermediate forms).
It breeds in high arctic regions in North America and throughout northern Siberia. Russian birds pass the Barents Sea and the coast of Norway annually during the migrations in spring and autumn to and from the wintering areas off West Africa.
The pomarine skua does not breed in Svalbard, but is regularly observed along the coast and in the waters surrounding the archipelago, especially in the south-east.
The pomarine skua usually occurs in flocks during migration, while the arctic skua is normally seen singly or in groups of two to four birds. Pomarine skuas are often seen following ships or flocks of other seabirds such as groups of black-legged kittiwakes.