In this movie: http://www.imdb.com/title/tt1675192/
Curtis saw the bird swarms as a prelude to doom. Some fantastic swarms on the web. http://www.youtube.com/watch?v=qJjeHLcbQJ0 http://www.youtube.com/watch?v=A6nvvFkbRkY http://www.youtube.com/watch?v=XH-groCeKbE