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.

Scapulars, lesser coverts and tertials show adult-like greyish black colour. Primaries with obvious white tips and distinct mirror on P10. Still many vestiges of immaturity in several feather tracts indicate 4cy.