A seabird that breeds on Arctic tundra and may steal food from other seabirds. Adults vary from dark to pale color forms.
Plumage ranges from a dark blackish-brown form to a paler form with a whitish belly. Breeding adults have elongated central tail feathers.
During the breeding season it feeds on birds and eggs on Arctic tundra. At other times of year it lives at sea and may chase gulls and terns until they drop their food.
An extinction-risk assessment has not been added yet.