Albert de Jong
Larus cachinnans 2CY PNHA November 06 2014, Terschelling, the Netherlands. Picture: Jacob Jan de Vries.
Yellow PNHA, ringed as pullus on May 24 2013 at Kozielno, Paczkow, S-SW Poland, (50°29' N, 16°58' E).
In this area are mixed breeding colonies (near Katowice), with far most birds breeding here are cachinnans, but in this area also records of very few michahellis from the south (e.g. ringed female from Italy) and argentatus from eastern Germany are possible (see PDF).
PNHA is cachinnans. Complete moult is finished, P10 fully grown. A subsequent 'partial autumn moult' is in progress / just finished; many fresh wing-coverts and 2 upper tertials replaced again. These new feathers have a grey base.