Birdsong is being played in public buildings to highlight the decline in the UK bird population.

More than 5,000 venues are taking part, including London Underground stations, Murryfield and Hampden Park stadiums and Lincoln Cathedral.

The RSPB said it was to a reminder of "what we all stand to lose if the crisis facing nature is not addressed".

According to a recent government report, the number of birds living on farmland has decline by 46% since 1970.