The great skua (Stercorarius skua), sometimes known by the name bonxie in Britain, is a large seabird in the skua family Stercorariidae. It is roughly the size of a herring gull. It mainly eats fish caught at the sea surface or taken from other birds.
Adults are a streaked greyish brown, with a black cap, while juveniles are a warmer brown and unstreaked below. They have a short, blunt tail, and a powerful flight. The great skua's call is a harsh hah-hah-hah-hah; quacking and croaking noises have also been heard. Distinguishing this skua from the other North Atlantic skuas (parasitic jaeger, pomarine jaeger and long-tailed jaeger) is relatively straightforward. The herring gull size, massive barrel chest and white wing flashes of this bird are distinctive even at a distance. It is sometimes said to give the impression of a common buzzard. Identification of this skua is only complicated when it is necessary to distinguish it from the closely related large southern-hemisphere skuas. Despite its name, the great skua is marginally smaller on average than the other 3 large southern-hemisphere skuas, although not by enough to distinguish them by size in the field. Some authorities still regard the great skua as conspecific with some of these southern skuas, and as a group they have sometimes been separated in the genus Catharacta, although currently this taxonomy is not commonly followed.