156540 Gannet Morus bassanus W 165-180cm. Our largest seabird. Has deep, powerful wingbeats and glides on stiffly held wings. Bill is large and dagger-like. Dives from a height to catch fish. Sexes are similar. Adult has mainly white plumage with black wingtips; head has buffish wash. Juvenile has dark brown plumage speckled with white dots in first year; adult plumage acquired over next 4 years. Voice Silent at sea; nesting birds utter grating calls. Status Very locally common (3/4 of world population breeds here). Nests colonially but otherwise strictly marine.