This is one of the clouds of Starlings that were surrounding me on the Somerset Levels during a recent visit. The million or so birds roost overnight in the reed beds. If you have never seen this awesome Winter roost it's worth the trip where ever you live.
I just kept my finger on the shutter button and I'm amazed at the shapes I have captured as the flocks constantly change shape in a slow, fluid motion.
Canon 5D, 70-200 f2.8