Do birds sing because they enjoy it? Most people would say yes, but ornithologists point to the functional reasons of attracting a mate and defending a territory.
CHARLES HARTSHORNE , the American ornithologist, after nearly fifty years of world-wide study, expresses his belief that birds do have a genuine musical sense.
The programme is illustrated with recordings of the world's most gifted bird musicians from six continents.
Produced by Lillian Lang and Jeffery Boswall
Recorded in the BBC's New York studio: previously broadcast on April 1