Posted by Gary Potter (152.163.213.54) on August 16, 2000 at 23:16:13:
The bill of the gull does not seem massive enough for Glaucous Gull, even at the angle photographed. I think that the angle of the forehead would not look so flat in profile. This along with the long primary extension seem to eliminate Glaucous Gull. The white primaries & long extension seem to eliminate Glaucous-wing as well. The legs seem to be a darker shade of pink than either of these species also. I know that Thayer's Gull often shows legs of a deeper shade of pink, and to a lesser extent, I think this is also true of Iceland. Realizing that the color of the legs in a photo like this can be greatly affected by exposure, shadows, etc., I never-the-less, think that it is worth considering. I'll admit to being a bit shaky on gull identification, and then cast my vote for Iceland Gull.
Living in the Central Valley, I'm much more familiar with the Swallows than Gulls. I think that this is an immature Violet-green, because of the white above the eye, and the shade of green on the forehead and upper back. Tree Swallow would have no white above the eye and the green would be more of a metallic bluish green than the shade shown in the photo.