Pine martens were once common in Britain but now, they're one of our rarest carnivores. 

These slinky, tree-dwelling predators had virtually disappeared in England and Wales by the turn of the 20th Century.

But pine martens are making a comeback.

We follow Ranger Dan Iceton at Wallington estate in Northumberland, as he tries to encourage pine martens to make these woodlands their forever home.

And we discover conservation success in other parts of Britain where the animals have returned.

Follow the story and secret lives of the mysterious m...