What's this all about?

The jackdaws do it round here - I suppose they're a type of crow?

We've certainly seen crows mobbing the buzzards here, Aka. Quite an aerial display.

Buzzards don't making angry cawing noises that I'm aware of. Crows are noisy and angry-sounding.

Buzzards would take nestlings and crows nest high up in trees which would be vulnerable to buzzard hunting. Blackbirds (Turdus merula) nest lower in much bushier growth into which buzzards could not go.

I expect the black bird was a crow (carrion). We get lots of buzzards and crows here and there are lots of stand-offs, usually several crows mobbing one buzzard. I think it is usually territorial – defensive on the crows' part. I,ve never quite understood why, since the buzzards are probably hunting voles, and crows don't do that.

Thanks Flower I thought as it's the nesting season this might be the answer. It was such an unequal battle though. What a brave little bird. I don't know if he survived as I had to go out but I'll look for him tomorrow.

Definitely defending it's territory and potential young. Smaller birds will always attack birds of prey what ever the size. I have seen crows attack a golden eagle in the Hebrides. The buzzard doesn't rob nests at all but the blackbird is programmed to attack anything that looks like a raptor. Even herons will put up a flock of geese as it resembles a bird of prey to them.

Nature is wonderful.