With its distinctive red bill and legs, the chough is the heraldic bird of Cornwall. Once they clattered in their hundreds around Cornwall's coast, but for years one of the only places the Cornish chough has been seen is on pub signs. Crime writer Frances Fyfield does some detective work, discovers why these birds disappeared and finds that the choughs are beginning to return to the Cornish clifftops. ProducerMarya Burgess Tltch starts to twitch: page 41