This gull is another mixed bag of characters.
Once again, I had difficulty getting photos of this bird with other individuals of more obvious identity. Unfortunately, I was also unable to get a straight profile shot. That said, my impression was that the size of this bird seemed consistent with what I consider normal for Thayer’s Gulls. It seemed pretty small to me for a Glaucous-winged Gull.
Despite the apparently small size, I probably would have figured it was a Glaucous-winged Gull due to the gray wing-tips, since, as a relative new-comer to the challenges of gull identification, I tend to privilege that easy-to-see field-mark over others (though perhaps I shouldn’t). However, I’ve never seen an otherwise obvious Glaucous-winged Gull with pale eyes. After looking in Gulls of the Americas, I see that up to 1% of Glaucous-winged Gulls can have paler eyes, but the example given there has eyes that are nowhere near as pale this gull’s. I thought Kumlien’s Gull might be a possibility, but they seem quite a bit paler overall, from what I can tell.
I saw a similar gull last year (look at the last gull in the entry) and thought it was probably a Glaucous-winged Gull, but now I’m even less sure. Still, I can’t think of any reasonable hybrid combination that might result in this particular blend of characters.
Any help with this identification is certainly appreciated.