Great Black-backed Gull (Larus marinus)

(last update: July 12, 2015)

Great Black-backed Gull (Larus marinus) sub-adult: March 20 2004, IJmuiden, the Netherlands (52.27 N, 04.33 E).

This individual still shows many barred wing-coverts and an immature bill. The medial band on P10 is still broad and these primaries are most probably third generation, hence by March this is probably a 4cy bird.