They learn of a nature reserve, White Deer Park, where they will be safe, and undertake to make the journey together.

They form an Oath, promising to protect one another and overcome their natural instincts until they reach their destination.

The success of the book led to a further six novels detailing the adventures of the animals once they reached White Deer Park, and a prequel showing how Farthing Wood came to be destroyed.

The cover illustrations for this original series were painted by Portal artist Frances Broomfield.

Dann revealed in an interview with the "Green Action" radio programme on Q96 that the two-book version was special-issue for a children's book club that operated through British primary schools and included some illustrations left out of the original.