Crows and ravens are very intelligent. Ravens In Winter is a great book about an author who spent several winters studying raven behavior. It isn't dry reading at all.
I know. I'm a friend to cats and wouldn't want to see cats fighting like that, but those two were vicious and it was quite funny with the intensity and the bird watching. Thanks for the book recommendation. I wonder if my kids would like that...15, 9, and 6?