Adult winter possible Thayer's Gull

Thayer's Gull that looks like is here by Japanese Gull-site.

The impression receives Thayer's rather than American Herring

Back coler was thinner than Vega Gulls.

Note the P10 mirror pattern and P5 small black marking.

I think leg is short but he doesn't understand because it doesn't stand.

Note the bill size with adult Slaty-backed Gull.

Is it unquestionable as wing pattern of Thayer's?? Please your comment here.

There is a type with a lot of black markings also in Thayar's Gull taken in Choshi. By Japanese Gull-site.

From Mori Hokkaido Japan. December 29.