We have had a very angry crow in our back yard this week. Very angry - or so he sounds - and very, very vocal. What's been amazing is quite how varied his conversational repertoire is - now just caw caw, caw cark cark cark cark cark, but a whole range of sounds that including yapping, gargling, and a very disconcerting sound like a tight cork being pulled from a bottle. It's unclear whether everyone within range is being warned away from a nest, or whether he intends this stream of abuse as a form of rough courtship. Alternatively, maybe he's just rehearsing for a crow vocalist competition. Bird people - do you have any insight?