Herring Gull 2cy (argenteus), December 23 2010, Scheveningen, the Netherlands.

Tail and primary pattern typical for this age. Note also the vermiculation on the extensive brown secondary centres, typical for 2nd gen feathers. Primaries brown, without white tips on central feathers.
Already grey saddle by adult-like scapulars, as is commonly found in local argenteus (but bird not ringed). Upper tertials, inner gc, central mc, central llc and many lc replaced recently, in the partial autumn moult. Pattern much more adult-like, grey feathers.