The unique and spectacular beauty of thousands of European starlings in synchronized motion, a phenomenon called a murmuration, is something that never fails to awe. Seen from a distance, these dancing clouds are mesmerizing in their pulses, twists and dives.

Why starlings murmurate is still something of a debate in the scientific community. The massive aerial displays may be defense mechanisms against predators such as hawks and falcons or calls to other flocks to come together for warmth.

"It's much warmer to roost as a big group rather than a smaller one and the murmurations can be as big as 100,000 birds," Dr. Anne Goodenough from Gloucestershire University told the Belfast Telegraph. "Why is it only European starlings that undertake massive aerial displays for sustained period before roosting? We don't really know."

Whatever the reason, they certainly are something to behold. Check out the sunset murmuration of European starlings captured on Christmas Day 2016 in Logroño, Spain below.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.