www.gull-research.org

Hello.
I took this picture in Istanbul on December 14th. Was bigger that a typical Common Gull that I can see in Spain and also the molting is delayed compared with first winter I see regularly in Spain

Delfín

hi delfín,

you can't definitely ID them in the field (although chris gibbins has worked out quite some criteria for vagrant heinei) but on location alone (istambul) this should be a heinei.
they also seem to be more prone for a retarded plumage (brown scaps) but canus can show that too.

feliz navidad!

lou