Mongolian GullL.c? mongolicus
16th November 2002 Choshi Chiba Japan
A relatively fresh Mongolian Gull.
An advanced Mongolian Gull, and a juv/1st winter Vega Gull (background). Compare their overall colorations
Interesting markings in the inner primaries.
Broad white at the tail tips. It may resemble tails of adult Black-tailed Gulls, from a distance.