Great Black-backed Gull

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. It is grayish-black on the wings and back, with conspicuous, contrasting white "mirrors" at the wing tips. The legs are pinkish, and the bill is yellow or yellow-pink with some orange or red near tip of lower bill. The adult Lesser Black-backed Gull is distinctly smaller, typically weighing about half as much as a Great Black-back. The Lesser Black-back has yellowish legs and a mantle that can range from slate-gray to brownish-colored but it is never as dark as the larger species.