This video has been shared many times online, but it's worth sharing (and watching) again and again. Filmmakers Liberty Smith and Sophie Windsor Clive have captured one of the most incredible sights in the natural world: a murmuration of starlings, above an island in the river Shannon, Ireland. Liberty and Sophie's website can be viewed here: www.islandsandrivers.com. It includes several more of their short films.
But for now press play, watch, and watch again.