| Great Black-backed Gull | |
|---|---|
 Adult in summer | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Charadriiformes |
| Family: | Laridae |
| Genus: | Larus |
| Species: | Larus marinus |
The Great Black-backed Gull (Larus marinus) is the world’s largest gull. It has a very dark grey (almost black) back, hence its name.
Appearance[]
| Measurements | |
|---|---|
| Length: | 70 cm (27.5 in) |
| Weight: | 1-2 kg (2.2-4.4 lbs) |
| Wingspan: | 165 cm (65 in) |
The adult Great Black-backed Gull in summer plumage has black wings and back, with white underparts, tail and head, and a yellow bill with a red spot on the lower section. It also has a white trailing wing-edge, a white daub at the end of the wing and pink legs. The adult's winter plumage is similar, but with a few dark markings on the head and neck. The juvenile is whitish with brown markings all over its body, mostly on the wings and back, a black bill, and greyish legs. It has a generally paler appearance than other juvenile gulls. The outer primaries are noticeably darker than the inner ones. The tail is mostly white with a broad dark band, and a narrow white band at the very tip. The ageing process in very slow in this gull, with most birds acquiring the adult plumage on their fourth or even fifth year. This bird appears huge even when compared to large species such as the Herring Gull. It also has a proportionately thicker bill, and a more squared head. The most similar species, the Lesser Black-backed Gull, is smaller and has yellow legs and less white on the wings.
Voice[]
Its vocal repertoire includes a deep "auk", and a territorial call which resembles the laughing call of the Herring Gull, but is far deeper and hoarser.
Habits[]
Black-backed Gulls can be very disruptive to seabird colonies, as they harry the other birds and even eat eggs and chicks occasionally. Pairs, however, are often very solitary and highly territorial. Their laughing call is deeper than most gulls.
Feeding[]
The Black-backed Gull feeds mainly on fish and carrion, but will eat any animal it can kill, including rodents, small rabbits, molluscs, crustaceans, small gulls and auks, hatchlings, and eggs. It is also a kleptoparasite, harassing other seabirds to steal their catch. Prey is often swallowed whole, with the gull later regurgitating pellets of undigested material.
Breeding[]
It nests from May to July, with both sexes building a rudimentary pile of plant material where the female lays 2-3 olive-brown eggs with dark spots. Both parents incubate the clutch for about 28 days. The young are initially covered in beige, dark spotted down. They are semi-altricial, staying in the proximity of the nest and being fed by the parents for about 7 weeks before fledging.
Distribution[]
The Great Black-backed Gull breeds in Europe from northern France to Iceland, through the North Sea, Baltic, Scandinavia, and the Kola peninsula. In winter, it can be sighted south of its breeding range, all along the Atlantic coast of Europe. In America, the gull is found from Quebec to North Carolina in the breeding season, and as far south as Florida in winter. It is an accidental vagrant to the Mediterranean and the Mexican Gulf. It is a coastal species that breeds mostly in elevated areas on rocky islands.
Gallery[]
