Juvenile Hybrid Gull Larus sp

Like a Kumlien's Gull. Possible Gloucous Gull × Gloucous-winged or vega.

Note the long neck and small eye and large bill than Kumlien's Gull.

The color of bills of a lot of Kumlien's are black. But this bird bills color are black and pink.

From Abashiri Hokkaido Japan. January 6.