hi dimi, jeff, jan,
what a nice find on the other side of the globe! that said i strongly favour baltic gull over heuglini. it was my first impression and it still is, after having serious doubts. some things appear to point more towards heuglini, like the somewhat snouty look (longish bill), well pigmented iris, longish legs and p9 mirror, all this in combination! but as jan pointed out, some fuscus can show a dark iris. like in all LWHG taxons there is considerable variation in iris pigmentation. i can't find any reference on percentage in fuscus, but it is not at all common. also, only about 1 in 9-10 birds has a p9 mirror (acc. to olsen's gull bible)
so why do i still think it is a baltic gull?
1. i think it is much too dark mantled for a heuglin's gull (check e.g. all pics on gull-research of adult heuglini - can't even think why taimyrensis has been into the discussion)
2. head and bill shape (making the somewhat typical "jizz") perfectly fits baltic (much better than e.g. an intermedius) - triangular or, let's say pear shaped head, bill with elegant curve and, while on first view a bit on the long side for fuscus, it certainly fits a strong male baltic!
3. no ventral white tongues in primaries, a feature that most heuglini shares with the more eastern, cachinnans-like taxons (barabensis etc.) - but sometimes lacks it also.
in addition to avi's and amir's pics of heuglini on gull-research: http://gull-research.org/heuglini/05cyjan.html
see also chris' pics from UAE and note how pale mantled they are: http://chrisgibbins-gullsbirds.blogspot.de/2009/02/heuglinis-gulls-in-united-arab-emirates.html
while it is hard to exclude an intermedius, this taxon is not common even in the eastern mediterranean and is the least far migrant. edit: waitaminute: intermedius usually doesn't suspend moult as in this bird. exceptionally it has been observed in graellsii and i guess the same thing probably should be valid for intermedius (but haven't seen it mentioned anywhere, yet). but in a vagrant context, moult can get mixed up...
female kelp gull is out for me on structure, esp. bill and head shape, leg colour and arrested moult.
it has been said that it doesn't show the brownish tingue of baltic, but i can well see it in some older greater coverts (esp. primary coverts) and in the earlier moulted p1 and p2. most of its plumage however is rel. fresh, so this is why it looks cold dark greyish. note how pale and cold grey this fuscus looks in sunlight: http://www.israel.gull-research.org...Blue LL AE4F8561 Ashdod sea shore 25.3.11.jpg
, and then in direct comparison to heuglini (left) and armenicus (middle): http://www.israel.gull-research.org...ni Gull AE4F8574 Ashdod sea shore 25.3.11.jpg
i wouldn't bother about the darkish underwing covert tips, the bird should be an (old) adult since a younger one (3/4cy) would not likely have a p9 mirror and a clean yellow bill. it just adds to the other oddities of this bird. head striation can be absent due to bleaching under tropical conditions and/or early prealternate moult. so, while it's sort of a tricky bird and i can't be 100% sure, my strong feeling is that this is a male larus fuscus fuscus.