Checking out the Birds in Swindon

I found myself changing trains at Swindon yesterday and had about ten minutes to wait and was captivated by the birds. That is not to say a new generation of the Melinda Messenger’s but the swallows.  The skies above the station were dark with a swirling, boiling mass of them flying in seemingly precise formations to create ever changing cloud patterns in the sky. 

Seemingly two “clouds” can crash into each other at great speed but no birds collide and a new cloud pattern forms. The picture below is not the greatest and cannot capture the speed at which the cloud patterns changed, but it was truly captivating. I was almost sorry when my train arrived and I had to stop watching.

PS. Darren says "I've heard that this is a non-water example of fluid dynamics. Each bird is concerned only about itself not crashing into its neighbour, the macro result being waves.". Whatever..it is a spellbinding sight.