Great Black-backed Gull (Larus marinus)

(last update: July 12, 2015)

Jean-Michel Sauvage (France)
Morten Helberg (Norway)
Nils Helge Lorentzen (Norway)
Mars Muusse (Netherlands)

Great Black-backed Gull (Larus marinus) sub-adult: January 13 2012, IJmuiden, the Netherlands.

Only single feathers in scapular region show adult-like greyish black colour. All still show internal pattern. Note typical white tips on secondaries and primaries and large mirror on P10, indicating this bird is already in 4cy, although upperparts may strongly suggest 3cy.