Small, dainty gull with rather long, slender wings and a rounded head. Breeding adults are white-headed with an unmarked yellow bill; nonbreeding adults have smudgy brown markings on the head and a faint dark marking near the tip of the bill. Note dark eye. Immatures are brownish, with black-tipped pink bills. Known as Common Gull in Europe. Variable across extensive range, sometimes considered multiple species. North American birds known as Mew Gull, Eurasian birds as Common Gull. Breeds in wetlands, meadows, and along rivers. Winters in any open wetland habitat, especially beaches or sheltered coastal waters. Most similar to Ring-billed Gull, but smaller and smaller-billed. Immatures are especially difficult but note Mew Gull is more uniformly brownish.