Gould observed that 'The Lesser and Greater Black-backed Gulls are so precisely alike in form and colouring, that it is by the great difference in their size that they can be distinguished from each other.'

An adult bird is depicted in summer plumage (foreground) and a young bird behind.

DISTRIBUTION: Breeds northwestern Eurasia from Iceland, Faeroes, British Isles, France, and coasts of North and Baltic seas. Winters south to south Africa, Iranian Gulf, and in eastern North America from Great Lakes and Labrador south to Florida. In Britain increasing numbers breed and increasing trend for birds to over-winter