The sound of starlings singing for a mate could vanish from the British countryside because of high levels of antidepressants in the environment, a study suggests.

The University of York has discovered that male starlings sing less to females who have been fed diluted concentrations of fluoxetine, which is sold as Prozac.

In 2016, there were 64.7 million prescriptions for antidepressants in the UK and once they pass through the human body they often end up in sewage-treatment systems or waterways.

The new research focussed on birds who ate worms, maggots and flies at a sewage treatment plants which were found to contain traces of many different drugs, including antidepressants.

After measuring levels of Prozac at the plants, the team fed similar amounts to captured starlings and found that it made them less attractive to the opposite sex.