Mongolian Gull Larus c? mongolicus
March 19th 2004 Choshi Chiba Jpaan
Kamtchatka Gull(left）, Vega Gull（front）, Mongolian Gull（behind）
Mongolian Gull (left), Vega Gull (right)
Vega Gull (left), Mongolian Gull (right)
Note the longish overall structure, white head, black marking on the lower mandible. The upper mandible also has a black smudge, but it is hard to see in these images.
Note the primary-pattern that has black markings on P10-P4.