Thursday, March 24th, 2022

I think that’s probably a Black-headed Gull in the back. The foreground bird is interesting; the dark mantle makes me think it’s likely either Greater or Lesser Black-backed Gull. The leg color looks better for Greater.

Size-wise it’s tough for me to tell; I don’t have a lot of experience with relative sizes of these species. Lesser Black-backed Gull is the only one of them I’ve ever seen in person, and that was a single individual seen on a couple of different occasions at some distance.

Sibley gives the following lengths:

BHGU: 15.7″

LBBG: 21.7″

GBBG: 28.7″

So I guess I have to ask myself, does that foreground bird look like it’s 13 inches longer than the background bird? Or only 6 inches longer? I think I’m leaning toward GBBG, since if its head weren’t tucked in I suspect it would look a lot bigger than the COGU. That plus the leg color isn’t enough for me to feel like it’s a slam-dunk, but I’m at least leaning in the GBBG direction. I wonder if there are any photos that show the foreground bird better. It would be interesting to see the extent of dark streaking on the head and nape.

Anyway, I knew that both of the black-backed species were potentially present in @seeseagulls’ vicinity, but hadn’t seen one show up in their blog before. Cool!

Reposted from