What is a murmuration, anyway?

Common Starling (Sturnus vulgaris)

“Starling (5503763150)” by Tim Felce (Airwolfhound) – StarlingUploaded by russavia. Licensed under CC BY-SA 2.0 via Wikimedia Commons

A murmuration is a group of starlings. Like a herd of cattle, a pack of wolves, or a posse of vicuña: a murmuration of starlings.

Many Europeans consider starlings pernicious pests. Murmurations of starlings can be enormous – sometimes up to a million individuals. They make a racket, and they poop, and their roosting can be an eyesore to some.

But when they fly together, the visual effect is simply amazing. Like a living lava lamp, a murmuration swirls through the sky, inspiring amateur videographers since the advent of YouTube – and professional ones since well before.

Math, Data, and Starling Murmurations

For those among us who’ve never watched PBS or BBC nature programming, here’s a short video:

In the beauty of this aerial dance I see mathematics, and I see data. Each individual is a data point, and each has a 4-dimensional vector (the dimensions being x, y, z, and time). As a collective, the perceived image is completely different depending on where the observer is standing, and it is a dynamic image to boot.

The mathematics of starling behavior, not surprisingly, have been investigated by people much smarter than I am. (If you have $36 worth of curiosity, you can read Empirical investigation of starling flocks: a benchmark study in collective animal behaviour, published in 2007 by 11 Italian scientists. And if your curiosity is more of the public library variety, check out Scale-free correlations in starling flocks, a 2010 paper by several of the same scientists.) The mathematics of how these birds avoid mass midair collisions, and why they behave this way, are really fascinating. And very much evocative of “Big Data” and “Data Science”.

OK, but why name the blog for the birds?

Starlings are not the only animals in nature to form these highly fluid, entrancing swarms. Austin, Texas, is home to millions of Mexican Freetailed Bats who put on a show each spring. And sardines form massive undulating “bait balls” to defend themselves against the many predators they must avoid.

a Bait Ball, with predator

The math of bait balls is just as fascinating, and just as beautiful, as that of starling murmurations.

But I wasn’t going to name my blog Bait Ball.

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