The Great Black-backed Gull is the largest gull in the world. It is 64-79 cm (25-31 in) long with a 1.5-1.7 m (4 ft 11 in-5 ft 7 in) wingspan and a body weight of 0.75-2.3 kg. This bird is bulky and imposing in appearance with a large, powerful bill. 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. Its upper-wings have a blackish coloration. Juvenile birds have, checkered black-brown upper parts, the head and underparts streaked with gray brown, and a neat wing pattern.
Habitat and Distribution
This species breeds in coastal areas from northwest Russia, coastal Scandinavia, on the Baltic Sea coasts, to the coasts of northwestern France, the United Kingdom and Ireland. Across northern Atlantic,it occurs in Iceland, southern Greenland and on the Atlantic coasts of Canada and the U.S. During winter in the Baltic Sea the bird usually stays close the ice boundary. Their occur in coastal habitats, including rocky and sandy coasts and estuaries, as well as inland wetland habitats.
The Great Black-backed Gulls are opportunistic feeders. They will hunt and kill any prey smaller than themselves. They get most of their dietary energy from scavenging, with refuse. Alternate foods, include berries and insects.
They make a lined nest on the ground often on top of a rocky stack, fallen log or other obstructing object which can block the contents from the elements. In urban environments, they nest on rooftops. The female lays usually three eggs between late April and late June. It takes around one week for the female to produce the three eggs and all three hatch at the same day. The eggs are greenish-brown with dark speckles and blotches. Both parents incubate for about 28 days.
Calls and Songs
The call is a deep `laughing` cry, kaa-ga-ga, with the first note sometimes drawn out in an almost bovid-like sound.