Adult winter ''barrovianus'' Gloucous Gull
　Larus hyperboreus barrovianus ?

With adult Slaty-backed Gull. Note a body and bill size.

With adult Slaty-backed Gull.

Left bird. With nomarl type Glaucous Gull

2w ''barrovianus''Glaucous Gull and adult normal Glaucous Gull.

Noto the whitish primaries.

Comparison with presumed Kumlien's Gull that keeps coming to Choshi.

Note the bill and eye size.

From Wakkanai Hokkaido Japan. February 23.