Flocks of starlings swarm in Swindon
8 April 2013 Last updated at 09:24 BST
The long cold winter is the most likely explanation for thousands of birds flocking over the Wiltshire town of Swindon each evening, according to a bird expert.
Tens of thousands of starlings have been turning and swooping in perfect unison over the town centre during the early evening for a number of weeks.
John Maguire reports from Swindon on the 'murmurations'.