Watch: 'Murmuration' of birds over Great Falls (videos at link)

[JudyM]

8. Beautiful. Physicists explain...

From the article, quoting Hoe Stuff Works:

Italian physicists used more than 400 photos from several videos to find out, plotting the position and speed of birds as they flocked. From that, they built a mathematical model that identified the optimal number of flock-mates for each bird to track.

Turns out the magic number is seven: Each bird keeps tabs on its seven closest neighbors and ignores all else. Considering all these little groups of seven touch on other individuals and groups of seven, twists and turns quickly spread. And from that, a whole murmuration moves. The scientists' findings were published in the journal PLOS Computational Biology in January 2013.