Do Birds Mob Foxes? Yes.

 Someone reported seeing a fox walking by that was swoop[ed down on by a crow and asked whether anyone else had seen anything like this?

It's very common. Historically magpies and foxes have had a "fractious" relationship and crows and rooks are not too keen on foxes either and they will swoop down and peck or pluck clumps of fur off a fox.

Medieval prints show Old British foxes play dead so that they can catch a crow or magpie that gets close. In the old fox hunting days if hunts lost sight of a fox they waited for crows or magpies to sound off and follow the fox -giving away where it was. Definitely not a friendly relationship!

It is an odd sight when you see it but the birds see the fox as almost a cat -and they mob those here!

Above: No problem and this demonstrates that odd relationship between foxes and birds Bodleian Library, MS. Ashmole 1511, Folio 23r  A fox plays dead to lure birds to their doom, while other foxes watch from their burrows

Above: Bodleian Library, MS. Bodley 533, Folio 7v The fox plays dead to lure birds to their doom.

Above: Bodleian Library, MS. Bodley 764, Folio 26r

This image shows two phases of the fox's hunting strategy. It rolls in red mud to simulate blood, and lies on its back pretending to be dead; when birds land on or near, it catches and eats them. This is a behaviour we do not see in the imported foxes but was apparently often observed in the past.