Could the return of the Pine Marten mean the end of the Grey Squirrel takeover?

Tom Heap examines emerging evidence that where Pine Marten populations are healthy, Grey Squirrel numbers crash and native Red Squirrels increase.

Tom meets the researchers who found the connection in Ireland, and who are now investigating whether it's also happening in Scotland.

The Pine Marten is itself recovering from years of persecution and is still only found in tiny pockets of England and Wales. If the Pine Marten really is the saviour of the Red Squirrel there could be an added incentive for its reintroduction.

Presenter: Tom Heap
Producer: Sarah Swadling.