1985: Coal mine canaries phased out
The government announced plans to phase out canary birds in mining pits on 30 December 1986.
Over 200 canaries were replaced by electronic detectors, which were more effective in indicating the presence of air pollutants.
The removal of the canaries ended a mining tradition in Britain which dated back to 1911. Since then, two canaries had been employed by each pit.
Originally broadcast on 30 December 1986.