Tens of thousands of starlings looked as though they were on military manoeuvres when they put on a spectacular display close to Catterick Garrison in North Yorkshire.
The early evening activity, on Wednesday 25 November, known as a murmuration, took place above a drainage pond beside the A1.
Crowds gathered at dusk to watch the birds twist and swoop in clouds, seeming to fly from all directions, before they bed down in reeds.
The display lasted around 15 minutes before dusk and scientists believe starlings may form them to protect themselves from predators.
Fred Watson, from Northallerton, said: "I thought it was great, the clouds, the shapes and how they come in - lovely, super."
David Kell, from Snape, agreed: "I thought it was marvellous.
"It was the first time I have seen starlings roost on the floor, and the numbers were immense."