Help topic: Identifying books/comic books/movies/anything

That is really early.

I've been trying to learn Gull. I am really good at Herring Gull and know many of their calls. Downtown last week when I was feeding Gulls with ' Mini Cheddars ' a Black Backed Gull (lesser) swooped and stole some young girl's Pizza Slice.

I clearly heard the Herring Gulls scream " You thieving bastard, that's just a young human "

The BBG screamed back, it sounded more like a Common Tern or possibly an Artic Skua.

This was strange as usually the BBG sounds quite similar to the Herring Gull.

I was just wondering if a book or video is available on this subject ?