Great Black backed Gull

This is the largest gull, bigger than a Herring Gull. It is 71–79 cm (28–31 in) long with a 1.5–1.7 m (5–5.7 ft) wingspan and a body weight of 1.3–2.2 kg (2.9–4.8 lb), though large males regularly exceed this weight.

This behaviour can commonly be observed in urban areas and landfill sites where the gulls feed on Feral Pigeons, rats and mice. They frequently rob other seabirds of their catch and have been known to follow feeding Humpback Whales, Porbeagles and Northern Bluefin Tuna to catch fish driven to the surface by the larger animals. Great Black-backed Gulls are major predators at the nesting colonies of smaller seabirds, killing and eating eggs, chicks and adult birds. Atlantic Puffins, Common Murres, Herring Gulls, Common Terns, Roseate Terns, Manx Shearwaters, Horned Grebes and Laughing Gulls are regularly killed and eaten by the Great Black-backs.