Dafundo beach 06.01.2012 - Adult Herring Larus argentatus argentatus.
Darker mantle, very much like our Yellow legged gulls, combined with primary pattern, and still growing P10, make it a good candidate for the northern subspecies.
With the courtesy of Isidoro Soares Teodoro,
Adult Herring 28.12.2012 at Santo Amaro de Oeiras with typical primary pattern of ssp. argenteus.