There's Room the Forest for Ever — Udo Weigelt

Freddy is furious! A new squirrel has arrived in his forest. His name is Morris and he is determined to stay. What's worse, the other animals seem to like Morris--maybe even more than they like Freddy. Hurt and angry, Freddy decides to move away. But when Morris's new home is threatened, Freddy has a change of heart. He discovers there really is room in the forest for everyone, and in the process, makes an unexpected new friend.