Lesser Black-backed Gull (graellsii & intermedius)

(last update: May 17 2015)

Lesser Black-backed Gull sub-adult, September 07 2015, Katwijk, the Netherlands.

Sub-adult bird with arrested moult, either advanced 3CY or retarded 4CY bird. Secondaries old brownish, adult-like pattern, limited black on bill may indicate 4CY. On the other hand, outer primaries seem to be old 2nd gen, which would indicate 3CY bird. Right wing: complete moult started, with P1-P3 new, P4 growing, P5 missing, P6-P8 old 3rd gen like, P9-P10 much older 2nd gen like. Similar sequence in left wing, except for 3rd gen like P10 with large mirror.