Photo 11: LBBG sub-adult, September 17 2001, Vuurtorenvlakte Maasvlakte, the Netherlands.
A sub-adult LBBG resting in a group of intermedius. P6 is full-grown and p9 and p10 are still old. The central secondaries were moulted recently and show neat tips. Some centres of the secondaries are just visible and have a slightly darker centre, as can be seen in sub-adult LBBGs in 4cy. Also note the tertials, which have the pale tips confined to the inner-webs and (just visible) the outer lesser coverts in the carpal edge which are brownish. Often, these outer lesser coverts are the last of the coverts to be moulted. Another clue for 4cy is the relatively small mirror on the old p10 primary.
This image is slightly over-exposed, but compare grey tones of these two LBBG with the immature GBBG (L. marinus) in the centre at the background.