Not long ago, as Rome passed through the final weeks of winter, a swirling black cloud flew in from the hills outside the city just before sunset. It whorled in the skies over my neighborhood, elegantly dancing to and fro and inside out. I’d never seen anything like it. My daughter thought it was a tornado. I was mesmerized. The whole thing seemed extraterrestrial.
The show took place every day in the late afternoon for more than a week. The performers were flocks of European starlings — gli storni – come to roost in Rome and elsewhere in Italy by the many, many thousands.
Despite the beauty of their aerobatics, the starlings are not particularly welcomed here.
There are some obvious reasons.
A more subtle and serious effect is the occasional blackout caused by way too many birds perching on electric power lines all at the same time. In the town of Brindisi, in the heel of southern Italy, outages once resulted when an army of starlings simultaneously took flight from their power line roost, triggering oscillations that interrupted the flow of electricity.
In Fasano, about a hundred miles north of Brindisi, the combined weight of the starlings caused high tension wires – in the words of a local newspaper – to be “sent into a tailspin.” In the Tuscan town of Montecarlo, a newspaper reported frequent blackouts and called the starlings “a scourge.” The city urged hunters to take up arms.
I checked with Terna, the Italian transmission grid operator, and was told that Rome did not experience any starling-induced blackouts this year. The city has used loudspeakers and light projectors to repel the birds with some success. A Terna spokesperson did point out that the company works with environmental groups to study the interaction between high-voltage lines and birds. One objective is to minimize avian collisions.
More than 9,000 special noise-making “dissuaders” – like this one – have been installed on the Italian grid to make power lines easier to see by birds in flight.
Each bird strives to fly as close to its neighbours as possible, instantly copying any changes in speed or direction. As a result, tiny deviations by one bird are magnified and distorted by those surrounding it, creating rippling, swirling patterns. In other words, this is a classic case of mathematical chaos (larger shapes composed of infinitely varied smaller patterns). Whatever the science, however, it is difficult for the observer to think of it as anything other than some vast living entity.