In the 25th year of the BBC's Natural History Unit, the second half of a series in 26 parts. Narrator David Attenborough
The roaring of the red deer stag, the shrieking of foxes, and the ultrasonic squabbling of rats are sounds that fill the British countryside at certain times of the year.
Tim Clutton-Brock of Cambridge University, Gillian Sales of King's College, London, and David MacDonald of Oxford University are attempting to understand when and why these animals use sound for communication.
BBC Bristol