Posted by Steven Mlodinow (205.188.197.186) on August 18, 2000 at 18:12:07:
Greetings All
I am throwing my lot in with the middle. I am going to equivocate.
First of all, among the tens of thousands of Glaucous-winged Gulls that I have seen in Washington, I have never seen a Glaucous-winged Gull that shows this bird's mantle/wing pattern. The problem is that Glaucous-winged Gulls get more Glaucous-like as one goes north, and my understanding is that, in Alaska, Glaucous-winged/Glaucous separation can get quite challenging at times. So, perhaps more northerly Glaucous-wingeds can show the gray mantle, clean white tertials/primaries of this bird. Notably, when considering Glaucous Gull, I have no problem with this bird's mantle color. It is in the shade, contrasting with the white-parts that are mostly in the sun. For an example of a Glaucous Gull with a very similar back color, see the Master Guide to Birding.
On the other hand, the eye should look bigger and whiter in Glaucous Gull, and the medium darkness of the eye is troublesome, though it may be a problem with shadowing. Soooo, I am not certain. With a better-lit look, I might feel much more comfortable. I do lean towards Glaucous.
Regarding smaller gulls, such as Iceland-- I agree with Phil, David, and others that the bill looks much too hefty for an Iceland. And regarding primary projection-- that can deceive. When I was but a wee lad, I saw an adult white-winged gull in Chicago. It looked massive, but the wing tips were quite long (like this bird). We photographed it. Larry Balch and Charlie Clark identified it as a Glaucous without a moment's hesitation. With the right moult, the right posture, etc. a Glaucous Gull can occasionally show significant primary extension beyond the tail.
Cheers
Steve Mlodinow