In winter, just before dusk, fleetingly, starlings fill the sky like iron filings, collectively swooping, dipping, surging into myriad forms as if coordinated by some vast magnetic pull. The name for a starling flock – and subsequently this phenomenon – is a “murmuration”, originally used to describe the sound of thousands of wings beating in synch.
The reason for these balletic aerial displays is for the most part unexplained, however, by applying “high-powered video analysis and computational modelling” to murmurations, Scientists were able to identify patterns more in line with “cutting-edge physics” than biology:
“Starling flocks, it turns out, are best described with equations of ‘critical transitions’ — systems that are poised to tip, to be almost instantly and completely transformed, like metals becoming magnetized or liquid turning to gas. Each starling in a flock is connected to every other. When a flock turns in unison, it’s a phase transition,” explains Brandon Keim of Wired Magazine.
“They call it ‘scale-free correlation’, which means that regardless of how many birds make up the flock, if any one bird turned and changed speed, so would all the others.”
The thought behind this is that each bird veers away from the edge of the group, where it is more likely to be caught by predators such as peregrines or sparrowhawks. The subsequent collective movement ripples across the entire flock. This idea correlates with when murmurations take place: roosting time.
“Numbers build up slowly near the roost over the afternoon as small groups of birds return from foraging in the area,” explains Paul Stancliffe of the British Trust for Ornithology. “By late afternoon there is a huge swirling cloud. It’s all about safety in numbers – none wants to be on the outside, none wants to be first to land.”
A vast murmuration, twisting like living smoke over the River Shannon in Ireland, was caught on camera by two tourists. The video went viral, underscoring the idea that, as Wired Magazine professes: “starlings may simply be the most visible and beautiful example of a biological criticality…hinting at universal principles yet to be understood”.