Classic Yellow-legged Gull, and very similar plumage wise to the first one, but with a more typical large head and a fuller neck, although not stretching as much as the other, and a wholly black bill. As correctly pointed out by Menotti, Yellow-legged usually has all blackish bill for a longer period compared to Caspian. Scapulars usually with bolder anchor marks in 1st winter compared to Caspian who shows narrower, but it´s a variable character also depending on time of year. Comparing the two gulls, one could certainly get a bit confused, as they look quite different in structure, the last one being more like a "text book" example of a Yellow-legged Gull, while the first has some Caspian characters, like long, bicoloured bill, and as mentioned by Menotti- the tertials, but also matched by many Yellow-legged. The pale surrounding to the eye is also a pro Caspian character, but then again also matched by some Yellow-legged. So, is it a hybrid, as suggested by Menotti? Or is it just that some eastern Yellow-legged shares characters with Caspian? I belive the latter, but not saying anything definitely about the gull.
JanJ