joszef szabo jun. sent me pics of two gulls which on water both had a remarkably short primary projection and thus rised the suspicion of argentatus. but both aren't straightfort to ID, at least for me.
the 1cy doesn't have a pronounced window but a venetian blind and shows a clear mask (see 2nd pic) - this strongly reminds of michahellis. but it is overall plain brown on underparts, seems to show darker tips of inner webs to inner primaries like often seen in tatus (but this effect might be caused by the row of pale longish spots on outer webs ending before the tip, which again could be in line with michahellis - see 3rd pic); tail band is not well visible but seems to be broad. inner greater coverts don't have the bold contrasting pattern of micha but a rather fine one, outer GC are darkened.
on balance i guess this could well be an eastern baltic (or russian) argentatus but i'm not sure - please help

the adult bird has a very strange primary pattern: p10 almost complete black (short tongue) but p8 and p9 have very little black for michahellis, note the incredible step of black between p10 and p9! the all white p10 tip and largish p9 mirror occures in many michas of the region and: this bird has a very solid p5 mark - with this it should not be an argentatus. strange male micha? but what about the short wing projection?
all the best and good gulling in 2013!
lou