Hello Whatbirders,
A gull mystery for everyone... I hope you can help me out. At a pier in Eastern Massachusetts today (Jan 19), I was looking at a Glaucous Gull (see first image, center), when the dark backed gull to the right caught my attention. (As you can see, I then tried to get a few pics of it and zoom in for better ID help, but the resolution isn't great.)
The dark gull appears to me to be about the same size or slightly smaller than the Herring gulls to the left of it. It has a rounded breast and a dark smudge around its eye. It's bill does not seem to me as dark and bulky as a Great Black-Backed Gull. Unfortunately, the ledge of the building cuts off all visibility of its legs, so leg color can't help us. The angle isn't so helpful for determining relative primary extension past the tail either. (I waited for a few minutes to see if it would move to a higher perch... no dice.)
Is this a Lesser Black-Backed Gull? I'm leaning in that direction but didn't want to talk myself into something.
Thanks for the help!