Adult summer>>winter
Vega Gull Larus vegae
Oct. 15th 2004 Tamagawa-river Kawasaki Kanagawa Japan

Both individuals are still summer plumage, except inner primaries that are invisible here.

This is starting to show some winter mottiling on its face. The visible folded primaries are old.

This individual is still summrer plumage, and has complete white head. Note that the visible folded primaries are old.

Molting from subadult summer? to adult winter.

P10-P7 are old.
Its P1-P4 do not have any black marking.

Slaty-backed Gull (left), Vega Gull (right)
Note the difference of their molt timing.

This had some yellowish tone on its legs. A simple yellowish-legged Vega Gull? or a 'taimyrensis'-influenced individual?