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) 3cy, April 19 2002, Le Portel - Boulogne sur Mer, France (50.42 N - 01.34 E). 

This bird has a small mirror on the outer and inner-web of p10. It would be nice to find out whether this presence of a mirror on p10 is related to breeding latitude or not. Some northern birds may look very delayed in upper-part moult, but can relatively often be found with a mirror on p10.