シロカツオドリ Morus bassanus

Large seabird of the Atlantic with long, pointed bill, wings, and tail. Adults bright white with cream-colored head and black wingtips. Takes several years to reach adult plumage; juveniles are all sooty-brown and slowly acquire more white as they mature. Nests in enormous colonies on cliffs in the North Atlantic. Spends most of its life at sea, although often fairly close to land, so they are often visible from shore or on whale watching boats. Dives torpedolike into the ocean for fish. Gathers in large feeding flocks, but sometimes solitary.