The sight of thousands of starlings flying en masse in a single, incredibly dynamic flock is known as a murmuration. The phenomenon is not entirely understood, but it is a marvel to observe.

An arty video of a murmuration, captured by a film crew that was shooting a commercial in Marseilles, France, has been widely circulated on the internet this week.

If you haven’t yet seen it, we share it with you here. It’s worth a look:

The Telegraph of the United Kingdom says such events “must be one of the most magical, yet underrated, wildlife spectacles on display in winter.”

The newspaper’s report includes a video clip of another murmuration and provides the view of a U.K. ornithologist on what leads the small birds to create such a dense, frantically kinetic scene.

“It’s all about safety in numbers,” he says. “None wants to be on the outside, none wants to be first to land.”

Murmurations are most common in the U.K. and northern Europe. Many readers are probably already acquainted with a much-shared video captured a year or so ago by a couple of canoeing friends touring a river in Ireland when, ta-da, up popped a dizzying murmuration:

If you just can’t get enough:

• Photos of a murmuration from 2011 in Scotland.
• A look of the science of murmurations, from Wired magazine.
• Starling factoids from Wild Birds Unlimited.
• A U.K. naturalist discusses murmurations in the video below: