Great Black-backed Gull (Larus marinus)

(last update: July 12, 2015)

Great Black-backed Gull (Larus marinus) sub-adult, March 17 2003, Boulogne-sur-Mer, France (50.42 N - 01.34 E).

In all repects this bird resembles a full adult, with very limited barred coverts (but note the pattern of the central greater coverts), but with an obvious bill-band. Note the complete white tail and very large white tips of the outer primaries and an obvious white mirror on the outermost primary P10. This is probably a 5cy bird.