Hi @Great Argus, do you have any information on whereabouts this picture was taken? I would love to know to be able to assign it to a subspecies in the photographic guide.
@Mr. Zootycoon Certainly do, it was taken on the southern side of Monterey Bay, California. I do know that happens to be the rough subspecies border so I don't know that it makes your job easier but hope that helps!
Edit: I'm surprised to see I'm the only one who's uploaded Western Gull to the gallery, I should have both subspecies in my archives, I'll take a look tomorrow.