Mumuration, Complexity and Culture

Last night, as dusk descended over Bodmin Moor, I watched one of natures most spectacular phenomena; a mumuration of starlings.

Tens of thousands of birds flying together in (seemingly) synchronised, ever-shifting patterns.

Scientists have long studied the spectacle, to try and understand both the causes of the behaviour and the flock’s mesmerising coordination.

In the 1930s, ornithologist Edmund Selous proposed that starlings might possess telepathic abilities.

By the 1980s computer scientists had developed a simulation of flocking behaviour in which birds followed three basic rules on: 1) separation (near birds moved further apart to avoid crowding), 2) cohesion (distant birds moved closer together to maintain unity) and 3) alignment (birds adjusted their direction and speed to match their neighbours).

Despite the simplicity of these rules they found that they could replicate amazingly complex group behaviour.

More recent findings have challenged previous theories, discovering that murmurations operate with each bird interacting with a fixed number of (six or seven) neighbours, regardless of how far apart they are.

The starlings can simultaneously process information from this cohort of flying neighbours, which is how they achieve “scale-free correlation” (where the behaviour of one bird affects all others in the group, regardless of the size of the flock).

As such murmurations have no central control, with this correlation allowing thousands of starlings to change direction simultaneously, without any single bird leading the movement.

Whilst the precise mechanisms remain uncertain a murmuration behaves as a critical system, finely balanced and responding instantly to environmental changes.

Recent discoveries also include that: 1) the birds fly at a steady speed (although it appears as if they slow down or speed up, this is an optical illusion caused by a 2D view of a 3D phenomenon) and 2) they may be able to focus on the position of dark-to-light edges on the boundaries of the flock, enhancing their seemingly psychic reactions.

The underlying factors driving mumuration behaviour are thought to include protection from predators, temperature regulation, aerodynamic efficiency and social interaction.

But what is fascinating is how seemingly simple local rules can lead to emergent complexity in the flock, how this can take place in response to environmental stimuli with no roles of leader or follower, but with primary cues taken from the closest neighbours.

And also the wider insights to be gained into the behaviours of a group from applying the disciplines of biology, physics and complex adaptive systems.

Organizational culture anyone?