Black-headed gull
Larus ridibundus
Identification Tips:
- Length: 13 inches
- Small, tern-like gull
- Short, thin bill
- Undersurfaces of primaries are black (except outermost is white)
Adult alternate:
- Dark brown head
- Dark red bill
- Very narrow white crescents above and below eye
- White nape, neck, breast, belly, and tail
- Pale gray back and upperwings
- Pale scapular crescent and tertial crescent
- White wedge on top of outer primaries
- Black tips to primaries creates black trailing edge to primaries and black
wingtips at rest
Adult basic:
- Like adult alternate except lacks dark hood and instead has black spot
on ear coverts
First year:
- Head and body like adult basic
- Pale-based bill
- White tail with black terminal band
- Pale gray upperwing marked by dark carpal bar, dark trailing edge and
slight white wedge in outer primaries
- Second-year birds are essentially identical to birds in adult basic
plumage
Similar species:
Bonaparte's Gulls are superficially similar but have dark bills in all
plumages and pale undersurfaces to the primaries. First-year Bonaparte's
have thinner carpal bars and trailing edges to the wing. Adult Little
Gulls have no black on the uppersurface of the wings, dark bills, and have
wholly dark underwings. First-year Little Gulls are easily distinguished by
the pale trailing edge to the wing and dark bill. Laughing and Franklin's
Gulls both have much darker gray backs, never show similar wing patterns and
have much thicker, more robust bills. First-year Ring-billed is somewhat
similar to first-year Black-headed but lacks the dark ear spot and dark
underwings.
Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.