In many parts of the world, one of the surest signs of the changing seasons are the flocks of migrating birds. For North Americans, a common site is the "V" formation of honking Canada geese trucking south in autumn and north in spring. In the Scandinavian country of Denmark, one of the birds people are used to seeing is the common starling. Flocks migrate through the country on their ways to winter homes in places like Spain and southern Italy. And every fall in Denmark's Wadden Sea National Park, the starlings put on a spectacular display that brings tourists from miles around.
It is called the "Black Sun." And it's really something to see!
Ducking, diving, weaving as one
Starlings stop at Wadden Sea Park briefly to eat and sleep before moving on. The number of starlings that can stop at any one time can come close to a million birds! Though these medium-sized birds are actually full of dark greens, rich purples, and tiny flecks of white, from a distance, they appear to be black. Especially when in a huge flock (a flock of starlings is called a murmuration, by the way).
The magic really happens when birds of prey, such as hawks, appear. No sleep for those starlings! Instead, they have to use their particular defence strategy. At the first sign of trouble, they rise up together and swirl and twist as one. The flock weaves and bends across the sky in a variety of shapes. The idea is that a predator will find it very difficult to pick out a single target from the giant mass of birds. It's the same technique that schools of fish like herring use to avoid their predators in the ocean.
And just how great does it look? We've got video evidence. Sit back and watch these beautiful birds turn the sky dark as they become one!