3cy Yellow-legged Gull / Larus michahellis, Westkapelle - sea dike (The Netherlands) on 10 November 2008
Note the immature black bill, most 3cy Yellow-legged Gulls show an adult-like colored bill by this date. In the second picture together with a 1cy Yellow-legged Gull which has replaced the upper tertial and a few inner greater, median and lesser coverts to second generation feathers.
From: Ies Meulmeester, Tuesday 13 July 2010, 19:18
Another atypical 3cy Yellow-Legged Gull taken on 23 October 2008 at Westkapelle. Note the immature broad dark bill-band, the bill except the red spot and bill top is completely obscured by the black. And note also the dark eye! A very advanced 2y Yellow-legged Gull can rule out by the third generation primaries with a mirror on p10, complete white tail and the wing-covert/tertail pattern.