I have to admit that I tried already to check on this gull but received no feedback. I should came here first but as I am away from my computer for a few days, and do not want to wait, I will provide a few links to photos I had uploaded to my site earlier. I got some great help here in the past so I hope some people will share their opinions now as well. I am not convinced yet that this gull can be positively ID (mean without doubt) but I would like to be proven wrong.
http://www.pbase.com/mbb/image/141345790 , http://www.pbase.com/mbb/image/141345796
On wing from above
OK Thayer’s – Iceland (nominate and Kumlien's) Gulls and, of course, hybrids. I have no field experience with these gulls but done some reading recently only to find out that situation looks messy. Not only there are divided opinions on their taxonomy but it seems that too often one gull on photo is ‘believed’ to be different species/subspecies when check by different people. So chance to get positive ID often does not look too promising. Only recently I decided to stop turning my head away when I see some juvenile gulls but am seriously thinking about going back to this habit as in my case if I cannot positively ID an individual bird (or have somebody else to do that) my observations are worthless and practically waste of time. I do not care how many different birds I see during the day or saw in the past, or will in the future - I am not a ‘lister’. I am writing this info about myself only to show that I have no interest to look for ‘rarities’.
Why I have problem with this gull - I will not list location now as I do not want anybody draw any suggestions from that. This is to me purely theoretical - this gull is what it is and where it was find is not going to change the species that it belongs to, as is not going to change the sex for that matter. First it is very ‘petite’ (tad bigger than Ring-billed; smaller than Lesser Black-backed; obviously much smaller than Herring); tertials are lacking dark centered pattern (field mark typically listed and well illustrated in many guides for Thayer‘s but not for Iceland), to me primaries are not really darker than brownish color on some body feathers, secondary bar is not really prominent (see flight photo from above with even lighting) etc; but perhaps I should stop lengthy description of my worries as this case might takes a second for an expert to ID this bird. Of course I would appreciate any remarks on ID of this gull; also which field marks are important and constant and which are not in Thayer‘s - Iceland identification. I am afraid that unfortunately many interesting gulls are gone unnoticed as many people are afraid to keep asking the ID questions about so many gulls they see (me included).
In case more photos are needed I will be able to upload some more in couple of days as I am going to be away from my computer and might even have problem with checking my emails on regular basis during next few days.
Thanks in advance