Probably ringed as pullus at Zeebrugge, Belgium, tarsus left, ring code Bruxelles L-89427. Ringed as pullus at Zeebrugge (51.20N 03.11E) on July 07 1999.
An individual lacking white tips on the outer primaries and lacking a white mirror on P10. Apparently, some sub-adult LBbG (at least 4cy) have no mirror on third generation P10. There is some limited black on the upper mandible. The orbital ring is red and the iris is yellow without speckling. The red gonydeal spot doesn't continue on the upper mandible. Based on direct comparison with its partner, this is a female (code V1). Note the blackish median coverts, compared to the brown hued greater and lower lesser coverts. P1 is still old (complete moult not started yet) and R1 (central tail-feathers) have some central black.