Adult: Blackish gray mantle shows little contrast with black primaries. The primaries show small black tips and a small mirror on the outermost primary (P10, and sometimes on P9). The thick bill is yellow with an orange-red gonydeal spot. The legs range from greenish to yellow. The eyes can be pale or dark, with an orange orbital ring. In basic plumage, may show very limited fine streaks on head. Third-cycle: Adult-like plumage, but with brownish cast to wing coverts, some black in the tail, and black primaries without white tips or mirror. Yellow bill with blackish markings near tip. Second-cycle: Extensively white on head and breast, with an indistinct dark line behind the eye. Extensive dark gray feathering on the upperparts. Legs are dull greenish. First-cycle: Dull gray-brown overall with whitish head and breast. Uppertail coverts are white with dark barring. Tail is blackish. The large bill is mostly dark. The legs are dull pinkish. Very similar to Lesser Black-backed, but with thicker bill and shorter wing extension.

Length: 53 (cm) Wingspan: 135 (cm)

Habitat:

Beaches, harbors.

Behavior:

Out of range birds often join loafing flocks of other large gulls.

Feeding:

Scavenges. Also feeds on marine invertebrates.