Albert de Jong
Larus cachinnans sub-adult, December 29 2009, Westkapelle, the Netherlands. Picture: Ies Meulmeester.
Classic view of plumage shown by 4cy Caspian Gulls at the end of December. In this individual note the dull green-yellowish bill color and the broad black subterminal band at the gonys. Except from the bill and primary pattern(see pictures below) is the plumage of this individual in all respects like an adult. Note the subterminal black band on the top of P10 between the white mirror and the white primary tip and the black markings along the shafts of the primaries and primary coverts.