Gull in Peterborough Ontario

[cavan wood]

I was about to list this as a first year iceland, but noticed the primaries are a bit darker than the rest of the wing.  Thoughts?

Taken today in Peterborough, Ontario.

[akiley]

It's an Iceland Gull. Appears intermediate between what I would call kumlieni and thayeri.

[cavan wood]

Ok, thanks.  I'm  more than a little confused by that whole iceland, kumlien, thayer's gradient.

[akiley]

1 hour ago, cavan wood said:

Ok, thanks.  I'm  more than a little confused by that whole iceland, kumlien, thayer's gradient.

We don't know all that much about the Iceland Gull complex- a lot is unknown. But current believed taxonomy is this:

Iceland Gull is a polytypic species with three subspecies:

1) nominate glaucoides- of Europe which is thought to occur in the East on rare occasion. All white primaries with no gray whatsoever. But that ID is extremely complicated.

2) Kumlieni- ("Kumlien's Gull")

Adults with slight gray in primaries, and immautures with mostly pale primaries- Your birds' primaries are a little darker than I would like for a typical kumlieni

3) thayeri- the bird formerly known as Thayer's Gull. Much darker overall in immature plumages with darker brown primaries.

The problem is that there are many birds that fall somewhere in the middle of kumlieni and thayeri. We don't really know what that means. A lot of birds fit nicely into one or the other, but others not so much. It does seem like a gradient to some extent like you mentioned. There'll have to be a lot of work done before we really get to the bottom of the complex.

[cavan wood]

Thanks akiley, that was very helpful.

So Thayer's is no longer considered a separate species.   I missed that.

Scott

[egosnell2002]

Yeah I'd say mostly kumlien on this one, bill is very small, and body overall is pretty pale. Wing tips are a bit dark, but that's why it's a spectrum (glaucoides on one side to thayeri on the other as akiley said)!