Freeze takes toll on bird numbers at Grafham Water
There has been a marked drop in some bird populations after one of the coldest Decembers on record.
Grafham Water Nature Reserve in Cambridgeshire, a site of special scientific interest, attracts thousands of migratory birds every year.
Last January they recorded the highest number of coots and tufted ducks there in 13 years. But this January numbers are half what they would normally expect.