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, March 2000, IJmuiden, the Netherlands (52.27 N, 4.33 E).

An individual much resembling an adult with most of the upper-parts jet-black. Both primary p9 and p10 show a mirror and the tail is predominantly white. Nevertheless, a few immature features can be seen: a prominent black bill-band, single brown median and greater coverts and one tertial. Note the black markings on the central tail feather in the next image.