Black Sun

A yearly gathering of starlings occurs in the marshlands of southwestern Denmark in the spring and fall. Hundreds of thousands of birds flock together each night at sunset near Ribe and Tønder, small towns on the west coast of the country near the Wadden Sea.

The starlings gather in huge groups and form large formations in the sky, moving as one to guard against predators while attempting to find a place to nest for the night. These movements are called murmurations.

There is no apparent leader, and nobody is sure how the starlings communicate their large-scale and intricate movements. Half a million birds are known to gather at once, enough to fill the sky and block out the sun; this gathering is known as the Black Sun.