Farthing Wood - The Adventure Begins by Colin Dann (Paperback, 1995)

There had always been otters in the stream running through Farthing Wood - and that had never been a problem for the other animals before: both sets of animals were happy to leave each other alone. But when there is a shortage of fish in the stream, the otters take to coming ashore for new prey - and that is a problem. Suddenly, the Farthing Wood animals have to compete for food - and they don't like it. Lean Vixen and the others are determined not to starve, and that means deciding on a plan to drive the otters out once and for all ...