South Polar Skua, Stercorarius maccormicki
This fearsome predator of the ocean skies breeds in Antartica and has been seen at the South Pole. It then flies a circle route over the northern oceans in its winter, our summer. Most birders see them only on pelagic trips, at ten miles or more from shore. The stocky body, powerful steady-flapping flight, and the patch of white at the base of the flight feathers single out a Skua from the juvenile gulls.