Lesser Black-backed Gull EY68 7cy, April 06 2003, Nachtegalenkeet, Maasvlakte, the Netherlands (51.59N,04.02E). 

Probably an adult female ringed left orange EY68. The white tip merges with the mirror on P10. This bird was ringed as pullus at the nest, July 03 1997, now in its 7cy. Note the elegant, almost parallel bill which indicates a female. However, merged tip and mirror on P10 is not typical for females, which show less white in the wing-tip.

bottom: EY68 8cy, April 26 2004, Nachtegalenkeet, Maasvlakte. 

From April onwards at the same location as previous year, but breeding not confirmed.