This is surely a Kumlien's Gull. The primaries look dark grey, not black?

To me they look bright blue...

I agree with Josh. The primaires aren't black and it shouldn't be labelled Thayer's Gull.
The primaries of what I presume is the same bird can also be viewed here: http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=46811

Well i disagree, compare mantel color of the dark gull to the adult Icland Gull, show me a Kumlien´s Gull with sutch a dark mantle color, further more the bill is quite heavy, and last but importently, no litrature state that Kumlien´s Gull have/can have a subterminalband on p10, if you brows thru photos of Thayer´s Gull on the net, you will find a lot of photos that matches the markings seen on this induvidual.

To Sebastian, i cood have labeld the bird gull sp. but there is deffenilty very strong Thayer´s Gull feetures in it, and since all littrature i have been across do not mention Kumlien´s Gulls with a subterminalband on p10 i will not call this gull a Kumlien´s Gull.

Hi Rodmund

You've got a point with the subterminalband (see http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=46811). That is not normal for a Kumliens. But the colour of the dark markings on the primaries doesn't support Thayers-IID.
Were the primaries really black (and just seem greyish on the photo)? Or do you think it is a Thayer's Gull with greyish primaries? Or are you (like me and a few others) just very puzzled about the generel appearance of quite a few gulls this winter?

If we thake the mantle color, bill, subterminalband on p10 and structure of this gull, it says Thayer´s Gull.

But when we take the coloring of the primaries it may perhaps not fit Thayer´s Gull entierly.

The outer web on the primaries were black while the inner web were gray, but when it come´s to the subterminalbands they vere not all black, the subterminalband on p10 was black, on p9 it was more dark gray but with a black "frame", p8 was gray with a marginal thin black "frame", the subterminalband on p7 was black on the "outer web" but gray on it´s "inner web" and the markings on p6 were gray.

However, there are more Thayer´s feetures on this gull than Kumliens feetures.

I had a 2cy at Skálafjørður/Eysturoy, Faroe Island, 08.03.2009, http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=25975 it was not accepted as a safe Thayer´s Gull but as a Thayer´s/Kumlien´s Gull.

This Gull may or may not be accepted as a Thayer´s Gull but then it surly is a Thayer´s Gull x Kumlien´s Gull.

Here is a similar dark Kumlien's Gull from Ontario.

https://picasaweb.google.com/117329578255897846071/KumlienSThayerSGullsFromONTARIO#5577274574981870258