Gulls, Istanbul (1 Viewer)

[Val35]

Hi, I've just come back from a little trip to Istanbul on the first week of January. This city has a ton of gulls, most of which were definitely Yellow Legged and Black Headed with a couple of Commons and Mediterranean in the mix.
A few gulls still puzzle me though and I'd like your opinion on these...

1)
Caspian (the bird on the right, both pics same bird) ?

2)
My initial thoughts were Armenian until I saw the pale iris (but maybe this varies ?), so maybe just Yellow Legged (same bird on both pics, it's the one on the left in the second pic).

3)
Probably Yellow Legged but something felt odd when I saw it (bird in the background).

Thanks !

 

[lou salomon]

all birds are YLG. the 1st cycle / winter in pics 1-2 is advanced in plumage and has already some 3rd generation scapulars giving it the plainer grey appearance. bird 2 is a 3rd cycle (4cy now) and thus showing this much black to bill. bird 3 is a 2nd cycle.

 

[Val35]

I was pretty sure about Caspian, although now that I look at it, that plain grey appearance and bill fit Yellow Legged much better !
Seems like I still need to work on those gulls
Thank you for your detailed answer, much appreciated !
In the second bird, what made me think of Armenian isn't only the bill color (I knew that 3-4cy Yellow-Legged can show this kind of bill) but structure seemed very different to me from the adult Yellow-Legged on the right for example...could it be because they are male and female ?