UNCANNY MAPSomething happened hereOpen on the map

The Black Sun of Denmark

SkyTønder marshes, Southern Denmark, Denmark · Every spring and autumnExplained
Tune in on the map One of 2,000 strange cases on a globe you can drag

In spring and autumn, at sunset over the Danish marshes, the sky goes dark as a million birds swirl together in vast, shifting shapes.

What was reported

In the marshes of south-western Jutland, near the border with Germany, huge flocks of migrating starlings gather in spring and autumn. At dusk they rise together and wheel across the sky in great clouds, folding and stretching like smoke, before dropping into the reedbeds to roost.

With up to a million birds, they can blot out the setting Sun. The Danes call it sort sol, 'black sun'.

Explanations offered

Starlings gather in murmurations to protect themselves from hawks and falcons: each bird follows its nearest neighbours, and the whole flock moves as one. How they coordinate so quickly is still studied by scientists.

When
Every spring and autumn
Where
Tønder marshes, Southern Denmark, Denmark
Witnesses
Thousands of visitors each year
Status
Explained

Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.

More from Denmark