A massive flock of birds moving in waves of flight is one of the most amazing sights in the natural world. 

A recent BBC Earth Unplugged episode captured footage of 70,000 starlings on a nature reserve in the United Kingdom. Every autumn or winter the birds are known to perform this majestic dancing pattern at dusk before bedding down in the reeds at night.

No one knows exactly why they do it, but one assumption is that it’s a way to protect against predators who try to zero in on a single bird. Each bird tries to follow the bird next to it, resulting in the visual waves across the sky.

Murmurations, as they are called, occur all over the world among many species of birds. If you spot one in the UK, researchers want to know about. Report any findings to the Starling Survey with the Royal Society of Biology.

Photo credit: Youtube