Lesser Black-backed Gull graellsii EH6 11cy, April 19 2003, Nachtegalenkeet - Maasvlakte, the Netherlands (51.59N,04.02E). 

An adult ringed, left green EH6. This bird was ringed as pullus on the nest, June 21 1993, close to the current breeding spot. Note the large mirror on P10 and the neat primary tips. The central median coverts still look very fresh plain grey, but a few greater and lesser coverts have the fringes worn and a brown hue on the feathers. There is a small faint black line on the lower mandible and the red gonydeal spot doesn't extend on the upper mandible.