[Tweeters] yesterday's white gull in Burlington

[Gary Bletsch]

Dear Tweeters,
The same all-white gull that I reported yesterday (the 22nd) was apparently seen by two other birders. A bird answering the same description  was seen flying over the flats west of Burlington on the afternoon of the 21st; the bird that I saw was also seen and photographed at the ballfields after I reported it from there. 
I put it on eBird as a Glaucous Gull immediately, in order to alert birders, hoping that someone with a good camera might get better photos. However, I was able to add my mobile-phone photos to my eBird checklist today, so there are several more images to inspect. My photos are the best of a bad lot, though.
Caution: the following paragraph may contain 4-letter codes, or may have been produced in a facility that produces four-letter codes, tree nuts, gluten, and peanuts.
I think that this bird is most likely a leucistic individual, rather than a Glaucous Gull. It might be a GWGU, a GLGU, or a GLGU X GWGU, and it might be a leucistic individual of any of those categories. I don't think it's a "Thayer's" Gull, because the bill and the shape of the head seemed wrong--I see none of the "delicate-looking" or "gentle-looking" jizz of the Thayer's Gull in this bird. I suppose there might also be some Herring Gull in this bird's family tree, come to think on it.
I'd love to hear any opinions as to this bird's identity! 
Yours truly,
Gary Bletsch
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman11.u.washington.edu/pipermail/tweeters/attachments/20210223/e1daafe1/attachment.html>