Hokkaido Winter Gull ID (1 Viewer)

Place: Port Shukutsu, Otaru, Hokkaido, Japan
Date: Feb. 16, 2020 9:52 a.m.
Weather: Partly cloudy, cold -6C

Hi Everyone!

I am working on really sorting out my winter gulls for the area I live in.
Well appreciated for any help in ID-ing these 2 gulls in a group of Harlequin Ducks.

I THINK maybe a Glaucous-winged Gull taking off and a Slaty-backed Gull kicking back?

There are random fly-thru's in winter, as well as 1st-4th winter and juveniles
that I am keeping an eye in the sorting of photos to learn.

Need to double-check if I am on the right track for ID-ing or I am missing something. One slender necked gull and one thick necked gull is a little confusing looking thru the Olsen books for me.

Thanks so much!

Jeff

The gull taking off looks like a Glaucous-winged Gull but the one in the water seems like a Black-tailed Gull to me. It's quite small, has extensive dark marking on the bill tip and lacks the broad white tertial crescent of a Slaty-backed Gull.

Andrew :enters with lightning speed:
Bless You!
Thank so much
I always learn something new in this great forum.
And thanks for the pointers for the differences!

Jeff