Probable Glaucous-winged Gull in Michigan and Ontario?

Those of you following the Michigan listservs or our listserv, Ontbirds, have probably heard about the Glaucous-winged Gull that has been reported at Port Huron, on both the Michigan and (for the first time today) on the Ontario side of the river. I'm not sure what the consensus is on its identification, but it is being eBirded in Michigan as a Glaucous-winged Gull. This eBird checklist contains two photos of the bird. Its a tough angle and hard to get a judge on the "stoutness" of the bill among other features, but it does kinda look like a Glaucous-winged Gull.

Glaucous-winged Gull is a western species that has strayed to the Great Lakes several times, and even twice to Newfoundland! However, it has never been confirmed for Ontario. You may recall that back in July of 2011 I picked this species as the #4 most likely species to be added to the Ontario checklist. Since then, some very unexpected species were added to the Ontario checklist (pending acceptance by the OBRC) in Thick-billed Kingbird, Kelp Gull, Brown-chested Martin, and Brown Booby. Who would have seen that coming?

This probable Glaucous-winged Gull in Michigan was first reported by Ryan Dziedzic to the "Michigan Listers" listserv on Friday, November 8 and had been reported on the 9th and 10th as well.

 Today, Sean Jenniskens posted to Ontbirds:
 "90% sure that I had the Glaucous-winged Gull that has been being seen from port Huron today at 2:35pm from Point Edward Lighthouse. It was first seen on the US Coastguard pier, but after about 5min of viewing half the gulls took off and I followed the gull in flight as it flew north towards a distant group of gulls on US shore."

The identification of a 1st cycle Glaucous-winged Gull is fairly straightforward - a big gull with a stout dark bill, finely patterned upperparts, and wingtips that are a milky brown color (matching the color of the rest of the upperparts). The angle of the head often gives a GWGU an "angry" appearance (as opposed to a more gentler expression, like what one would see with an Iceland Gull, for instance).

It gets more difficult though - Glaucous-winged Gulls freely hybridize, especially with Herring Gulls, Glaucous Gulls, and Western Gulls. In some parts of the Pacific northwest, Glaucous-winged Gulls and Western Gulls hybridize to such a great extent that it can be hard finding pure individuals!

For this to get accepted as a new species for the Ontario checklist, these hybrids will have to be clearly and unequivocally eliminated and detailed photos will probably be needed.

I have plans to spend the weekend in the Point Pelee area - more on that later. But this Glaucous-winged Gull might change my mind. Normally I would drop (nearly) everything to chase a potential new species for the province (see: Brown Booby)  but I'm kind of hesitant on this one. First, the gull hasn't been easy to find and has been playing hide and seek on the Michigan side, plus has only been reported once on the Ontario side. I did not see any reports from November 11 or 12. Second, it can be hard to get motivated to chase an "unspectacular" first for the province, if there ever was such a thing, such as a fugly 1st cycle gull. Third, who's to say that this thing isn't a hybird or a backcross as of right now? And of course it could disappear before I could have a chance to chase it on Friday!

Anyways, I guess we'll see how this one plays out in the coming days...