Slender, long-winged gull, slightly smaller than Herring Gull. Adults show dark gray back and yellow legs; in winter note fairly heavy streaking on head and neck. Takes four or five years to reach adult plumage; immatures can be difficult to distinguish from other gulls, especially Herring. On first- or second-year birds, look for contrastingly whitish head with dark smudge around the eye, long wings, dark bill, whitish rump and tail base, and evenly dark wings in flight. Can be found around any body of water but prefers beaches and flats. Often with flocks of other large gulls. Common in Eurasia, wintering to Africa and Southeast Asia. Population in North America has increased dramatically in the last couple decades; now regular (even fairly common!) on the Atlantic coast, rarer inland and farther west.