I spent the period 28 Dec 2013 to 8 Jan 2014 in Istanbul. I spent most time in the city, looking at gulls around the fish markets and taking ferries across the Bosphorus. Yellow-legged was the most abundant gull, but there were also many Caspians. Here are some images of Caspian Gulls from the trip. Many many thanks to Dilek Sahin for her help and hospitality during my stay, and to the other Turkish birders I met during my time there. Istanbul is really a great place to watch gulls!
Many gulls follow the ferries and so provide great photo opportunities.
Some flight shots
And finally, a view of one of the boats crossing the Bosphorus. Fortunately feeding bread to the gulls is very popular, so they follow the boats as they cross back and forth...