Sort Sol

There is a phenomenon in Denmark known as Sort Sol (Black Sun) in which vast numbers of European Starlings gather and swarm creating black shapes against the sky just before evening twilight. These sixteen pictures were taken over the course of one hour during an evening in April 2006 (image created by Bjarne Winkler).
http://epod.typepad.com/blog/2006/06/black-sun-in-denmark.html

UPDATE: http://www.liveleak.com/view?i=970_1257546785&p=1