The annual bird census organised by the RSPB (Royal Society for the Protection of Birds)
Britain has lost half its house sparrows, and three-quarters of its starlings.
Also on this day ...
Birthday of Guru Har Rai (Nanakshahi calendar) (Sikh)
This day marks the birth of the seventh Sikh prophet-teacher.
31 January 1606: Guy Fawkes, one of the conspirators in the Gunpowder Plot, was hanged, drawn and quartered. He was born in York on 13th April, 1570.
31 January 1858: The Great Eastern, the five-funnelled steamship designed by Isambard Kingdom Brunel and John Scott Russell, was launched at Millwall. At the time, it was the world's largest ship.
31 January 1867: The four bronze lions at the base of Nelson's Column were completed.
31 January 1953: 307 people were killed when the Thames estuary broke its banks, flooding large areas of Kent and Essex.
31 January 1983: It became compulsory in Britain to wear car seat belts.