Slaty-backed Gull Larus schistisagus
16th October 2002  Sakawagawa-river Odawara Kanagawa Japan

Juv/1stwinter. Primaries are brownish, not black.

Same bird as above. But in this situation, it looks blackish like Vega Gulls  because of  the light condition.

A diffrent individual.

Vega Gull (left), Slaty-backed Gull (right)

A dark individual resembling simithsonianus. But the primaries are not really blackish in better light.

Adult winter.