The following is a entry that I did a week ago and tried to post. I must have
pushed the wrong button and it ended up in a separate file

Phil and other gull challenged TWEETERS,
HOW TO START GULL IDENTIFICATION using leg colors (and the National
Geographic Guide)
In starting to identify gulls ignore any but those adult gulls that are
close and perched or standing nearby.
Large pink legged gulls: (see below for the smaller ones). In our area
98% are in the WESTERN, GLAUCOUS-WINGED complex. They have a tremendous bill
with a bulbous tip (the end of the bill looks bigger than the base. Try not
to to worry about plumage details. [If they have gray wing tips they are
GLAUCOUS-WINGED and if they have very dark mantles (backs) and (at this time
of the year) a snow white head, they are WESTERNS. The rest are bastards (or
intergrades or Olympic or Cascadias or Columbias - all polite synomyns for
bastards). Close inspection reveals about 90% of the complex are Olympics on
the North Olympic Peninsula.]
One sentence capsules of the pink legged other reasonable possibilities:
Runts: THAYERS (see Gene Hunn's excellent rundowns on this species which
appeared on TWEETERS earlier in the week and save it in case you carry gull
study to a higher level. It is the best capsule I have seen.)
Light eye, not as heavy a bill, a lighter mantle and a somewhat smaller
bird (than the WESTERNXGAUCOUS-WINGED complex): HERRING. But beware of
calling this as there are a lot more light eyed bastards and THAYERS than
HERRINGS around, HERRING is uncommon here on the Olympic Peninsula, at least.

Large and all white with a bicolored bill (dark on the end, light at the
base with a SHARP division between colors): GLAUCOUS GULL. These are not
adults, the adults are uncommon here. They frequently have attractive fawn or
brownish feather edging..
We have three small gulls with pink or red legs and a winter black spot
behind the eye. The size difference compared to the Olympics is as of that
between tug boats and freighters. Only BONAPARTES is common.
Smaller gulls with yellow or green legs:
Very pale mantle, yellow eye and ring on bill: RING-BILLED.
Dark eye, red and black spot on bill and medium size: CALIFORNIA.
Dainty with thin all yellow bill: MEW.
Small gulls with black legs (uncommon on the westside or viewed from
land):
Smudgey partial hood: FRANKLINS.
Poorly defined spot behind eye: BLACK-LEGGED KITTIWAKE.

THE ABOVE IS DELIBERATELY VERY SIMPLIFIED .

When you are sure of an adult you can use it as a starting point. E.g.
MEW GULL. Are there young birds in the flock. What do they look like. What
does the adult look like in flight etc, etc.
In scanning flocks for unusual gulls, I look first with binocs to scan
the entire flock looking to see if there are any very pale or very dark
individuals. I next look with binocs for marked size differences. I usually
then move to a scope and look at eye color, bill size and shape etc.
Most gulls can be figured out and you can go as deep into the subject as
you wish but we all should be able to identify typical adults. If you don't
want an intellectual challenge, watch Monday Night Football.

Bob Norton
Joyce, WA