Medium-sized seabird; large for a shearwater but smaller than most gulls. Long, narrow wings held quite straight when flying. Look for sharply-defined dark cap, brown patch on belly, and dark markings on underwings. Notably larger than Manx Shearwater. Most similar to Cory's Shearwater, but note all-black bill, dark cap, and slightly quicker wingbeats on Great Shearwater. Breeds in the Southern Hemisphere. Prefers colder ocean waters; rarely seen from land, prefers to stay offshore. Found singly or in large flocks. Flies low to the water, often arcing upwards in windy conditions.