Great black-backed gull
（重定向自Larus marinus）
The great black-backed gull (Larus marinus), also known as the greater black-backed gull or, informally, as the black-back, is the largest member of the gull family. It breeds on the European and North American coasts and islands of the North Atlantic and is fairly sedentary, though some black-backs move farther south or inland to large lakes or reservoirs. The adult great black-backed gull has a white head, neck and underparts, dark grey wings and back, pink legs and yellow bill.