Albert de Jong
Larus cachinnans 4cy, February 08 2010, Riga, Latvia. Picture: Chris Gibbins.
A bird with soft, greybrown patterning in the coverts and some brown remaining in the tertials. All the plumage features and bare-part colours visible in this bird can be found from time to time in Herring Gulls, so it illustrates nicely the fact that identification of birds in this age group should be supported by structure and, ideally, voice.
Note dark on centre of greater primary covert and dark tertials.