While my girlfriend and I were visiting my brother in the city of Cádiz in southern Spain, we had the pleasure of observing this great spectacle of nature that is apparently a common sight in many cities throughout Europe during autumn and winter.
This is a video of a flock of European starlings (Sturnus vulgaris). At this time of year, these birds form flocks of thousands of individuals every evening. Two questions came to my mind while I was watching this: (1) Why are they doing this? And (2) How do these groups coordinate their movements?
Researchers are actively pursuing both of these questions. At least one of the reasons “why” they flock in such large numbers is to defend themselves against predators (same thing for groups of schooling fish). As to “how”, it seems that individuals keep track of 6-7 of their nearest neighbours and these beautiful formations emerge from these small-scale interactions.
There are still plenty of questions about this amazing phenomenon that scientists don’t have the answer to, but will probably be keeping them busy for years to come.
For more about the science behind this phenomenon, check out this in-depth article from Wired: Starling Flocks Behave Like Flying Magnets
Here is a link to recent research article that investigated how these flocks coordinate their movements: http://www.pnas.org/content/105/4/1232.full
And here is the project page of the European researchers studying this phenomenon: http://angel.elte.hu/starling/index.html
Last but not least, here is an impressive video from BBC: