Great Black-backed Gull (Larus marinus)

(last update: July 12, 2015)

Great Black-backed Gull (Larus marinus) sub-adult, June 24 2003, Boulogne-sur-Mer, France (50.42N,1.34E).

In many respects this resembles an adult bird, with typically immature pattern on the bill. The wing-coverts are very abraded and moult has started. The outer median and outer greater coverts have been replaced for pitch-black fresh feathers. The old wing-coverts still show a brown hue. The tail is completely white. The tips of the primaries are large and there are obvious mirrors on both P9 and P10.