A Great Black-backed Gull lands on a sign in a marina that reads 'Danger.'

Couple of Great black-backed gulls in the cliffs of Etretat, Seine Maritime department, Normandy region, France, Europe

A chick of a Great Black-backed Gull (Larus marinus), on Staple Island, Farne Islands, Northumberland, England, United Kingdom, Europe

Juvenile Great black-backed gull (Larus marinus) in flight, UK

Great black-backed gull (Larus marinus) and shag (Phalacrocorax aristotelis) sharing a rock. Hebrides, Scotland.

Greater Black-back Gull chick (Larus marinus). British Channel Islands

Great skua (Stercorarius skua). Great skuas will often approach boats at sea in the hope of food and will kill other birds up to and including great black-backed gulls. Hebrides, Scotland

Juvenile Great black-backed gull (Larus marinus) in flight, UK

White-tailed Eagle or Sea eagle (Haliaeetus albicilla) in flight with prey, and Great Black-backed Gull (Larus marinus) behind, Flatanger, Nordtrondelag, Norway, Scandinavia, Europe

White-tailed Eagle or Sea eagle (Haliaeetus albicilla) in flight with prey, badgered by a Great Black-backed Gull (Larus marinus) behind, Flatanger, Nordtrondelag, Norway, Scandinavia, Europe

Great Black-backed Gulls with a comb in the beak, France