When I’m out in Gloucester and I see Glaucous and Iceland Gulls, I can generally call them pretty quickly. There are clues that we perceive that help with size. The Glaucous Gull is a big gull, and the Iceland is on the small side.
But when I shoot them and get home many of the visual clues are gone. When you start to consider that there is plumage variation and hybrids out there, well, it gets to be a little more challenging. Such was the case last Saturday when I was happened on a group of out-of-town birders. I could point them out, “That’s an Iceland and see that brute over there, that’s a Glaucous.” Easy-peasy.
So I took some shots and headed home for the darkroom. Okay, were is the cockiness now? “Uh, er…this is a Glaucous second year bird…I think…” And then I start reaching for the field guides.
The Cock-of-the-Rock that I have below is an Iceland Gull. Classic. It’s on the smallish side, no black tips on the wings, and the bill size and forehead shape are good clues.
Look at this gull below. It is much whiter than the gull above, it’s got a black tip on the bill. It’s a Glaucous. “Ah, er”…out come the field guides again. Wrong!!! It’s a second cycle Iceland!
Here, take a clue form this Glaucous gull below. Look at the shape of the forehead and the size of the bill. The gray patches on the back are an indication of age. Compare that forehead to the bird above. See the difference? Iceland above, Glaucous below.
This forehead clue is helpful because is is fairly constant in the shape.
One last comment. This Iceland below is also a first year bird. Notice that he is whiter than the bird on the post above. Now I cautiously say “he” because my Nat Geo field guide tells me that the boys are white and the girls are brown. It’s the only place I’ve seen that called out.
I hope that this post is helpful. It is not that you need to memorize this stuff, just see the differences presented and make a good call. (I hope that I did. Gulls can be tough!)