Large shearwater with a crisp dark cap. Long, narrow wings are held quite straight when flying; wingbeats are stiff. Also look for messy brown patch on belly and dark markings on underwings. Notably larger and proportionally longer-winged than Manx Shearwater, and wingbeats are not as snappy. Also compare with Cory's Shearwater, but note all-black bill, dark cap, and slightly quicker wingbeats and straighter wings on Great Shearwater. Primarily an Atlantic species, breeding mainly on remote Tristan Island group in the Southern Hemisphere. Spends the nonbreeding season (May to November) in cool water in the North Atlantic, where it can gather in large flocks, often mixed with other shearwater species. Occasionally seen from land, but prefers to stay offshore.