辨識
Pale, medium-sized gull, smaller and daintier than Glaucous or Herring Gulls. Often looks cute with rounded head and small bill. Extremely variable plumage. Variation is apparently clinal across the Arctic breeding range, from darkest in the west to palest in the east. The palest adults have very pale gray backs and nearly pure white wingtips. The darkest birds, formerly known as Thayer’s Gull, are darker gray above and have blackish wingtips. Young birds range from almost pure white to medium brown, never as dark as Herring Gull. First-year birds usually have a mostly dark bill. Winters along both coasts of North America and in Europe, often near the ocean or on large lakes. Typically found in small numbers among flocks of other large gulls.