Thanks both!

It was a great afternoon.
This hedge-smashing behaviour is quite startling really, but it's not that well known. The old alpha male of the garden group used to indulge in it to frighten a lower-ranking male. Quite what it means to a fox, I don't think anyone knows!

Presumably it's some way of demonstrating strength, or at least aggression!
They do of course nibble at branches for other reasons too. This one was just playing:
The territorial display tends to be much more violent, and often involves the fox rolling around.