sibirmåke Larus vegae

A large, sturdy gull of East Asia. Adults have a fairly pale gray back, pale eye, and dull pinkish legs. Takes four years for immatures to progress from mostly brown to fully white and gray adult plumage; intermediate plumages are often mottled and messy. Extremely variable plumage can make identification tricky. Occurs inland and along the coast, frequenting river mouths, harbors, beaches, lakes, and ponds. Often forms flocks with other gulls. Back color of adults generally a shade darker than that of American Herring Gull. Very similar to Mongolian Gull, and separation is tricky, but has a larger head and bill; adults also generally have pinker legs.