Lesser black-backed gull Larus fuscus

Identification Tips:

• Sexes similar
• Large gull
• Slim bill with indistinct gonydeal angle
• Round head

Adult alternate:

• Bright yellow bill with red spot at gonys
• Yellow legs
• Yellow iris
• White head, neck, breast, and belly
• Dark gray back and upperwings
• White tertial crescent
• Black primaries with white tips and one or two white mirrors on outer primaries
• White tail

Adult basic:

• Like adult alternate but blurry brown streaking and spotting on head and nape

Juvenile/First year:

• Black bill
• Wholly brown body plumage but may be paler on head
• Back appears somewhat checkered
• Dark brown primaries
• Dark brown secondaries and secondary coverts
• Pinkish legs
• Dark outer primaries
• Pale rump marked with dark bars and appears pale
• Dark tail

Second year:

• Variably pinkish bill with black tip
• Pale brown head, neck, upper breast, and belly
• Dull brown upperwing coverts
• Dark brown primaries and tail
• Dark gray back
• White tail with black terminal band

Third year:

• Like adult basic, but often lacks adult bill pattern, wing pattern, and often retains a partial tail band

Similar species:

From the second year through adult plumage, the Lesser Black-backed Gull has a very dark gray back. Great Black-backed Gull has wingtips the same color as the mantle, not darker as the Lesser, and pink legs. Western and Slaty-backed Gulls are larger and have pink legs. Yellow-footed Gull is larger with a darker back, larger bill, and a restricted range. First-year Lesser Black-backed Gulls are very similar to Herring Gulls but have whiter rumps, darker wing coverts, entirely black bills through their first summer, and paler heads and underparts that are spotted with brown. First-year Great Black-backed Gulls have whiter heads and are larger with much bigger bills, and have more strongly checkered wing coverts and secondaries.