Can pigeons help tackle air pollution?
When you think of reducing air pollution, you probably think of electric cars and energy efficient light bulbs, but academics at Birmingham University believe pigeons are the answer.
'City Flocks' is a new project which sends pigeons - with sensors strapped to their backs - off into the sky to record more accurate pollution forecasts.
So I Can Breathe
A week of coverage by BBC News examining possible solutions to the problems caused by air pollution.
07 Mar 2017