Starlings murmuration captured at RSPB Strumpshaw Fen

Tens of thousands of starlings took to the air in spectacular murmuration caused by the threat of a sparrowhawk.

The flight of fear and pursuit was captured by Rupert Masefield, from the RSPB, at Strumpshaw Fen in Norfolk.

Often called a "ballet of the skies", experts believe starlings perform the aerial acrobatics to create safety in numbers, as a way of keeping warm and to exchange information about good feeding spots.