We are approaching the time of year when huge flocks of European Starlings (Sturnus vulgaris) can be seen in the sky forming fluid shapes and organic, flowing patterns.

In some places, like the coastal wetlands of southwestern Denmark, starling flocks can be larger than a million birds, prompting the locals to call them “black sun” because they actually darken the sky.

Within the flock, the individual starlings are capable of some of the most jaw-dropping aerial maneuvers ever witnessed. Flying at speeds up to 40 mph, an entire flock can make hairpin turns in an instant, somehow managing to avoid collisions.

How do they do it?

The flock of starlings acting as a swarm. - geograph.org.uk - 124593
Image from Wikimedia Commons

Scientists are beginning to unravel the rules that govern this complex behavior. By examining the correlations between the movements of neighboring starlings, researchers have shown that each bird pays attention to six or seven of its neighbors, using acoustic, visual, and tactile stimuli to gauge their relative position within the flock.

One of the researchers studying this phenomenon, had this to say in an Audubon Magazine article:

“It may be that these types of behaviors are like a mathematical by-product of the rules the birds follow,” [Frank] Heppner says. “It is entirely possible that you get unpredictable behavior out of predictable rules.”

Check out this YouTube Video:

Amazing, isn’t it? It kind of reminds me of the Windows “Mystify” screensaver.

This mesmerizing flocking behavior is a good example of an emergent property, a novel property that emerges with a step upward in the hierarchy of biological order.

Can you think of any other similar examples?