graellsii LBBG 4cy L - 89443 Bruxelles, October 18 2002, Westkapelle, the Netherlands. 

A near-adult (4cy) Lesser Black-backed Gull born in Belgium: ringed L-89443 Bruxelles, ringed as pullus on July 07 1999 at Zeebrugge (51.20N 03.11E). Note the combination of much black on the bill, white tertials tips confined to the inner webs in the upper tertials and the more adult-like primary pattern, with large tips. Compare the grey-tone of this graellsii with the Great Black-backed Gull and adult intermedius.