~ Posted by Simon Willis, June 28th 2012
If you go to Tate Modern and hear an insistent shriek on the air, chances are it isn't caused by the disturbing paintings of Edvard Munch, an exhibition of whose late work, "The Modern Eye", has just opened there. No, it'll be coming from the Tate's less famous but more permanent attraction—the peregrine falcon.
Today, the British Library released a CD called "Wild London: sounds of the city's wildlife", and the third of 29 recordings on the disc is the sound of the falcon's alarm calls. The CD's inlay gives a useful guide to where you can listen to the real thing. As well as the Tate, you can find the falcon at the Houses of Parliament, where its hectoring noise wouldn't be out of place at Prime Minister's Questions. The other recordings range from the throaty warblings of London's most ubiquitous bird, the feral pigeon, to the echolocation calls of the noctule bat—a curious combination of pips and pops that sounds like someone beat boxing while bouncing a ball.
As well as being engrossing in themselves, the recordings give a new complexion to the city, where the only noise you can normally hear is the cacophony of traffic and building work. In Epping Forest, we're told, we can find the muntjac—also accurately known as the barking deer—and on Hampstead Heath and in Hyde Park a tiny bat called the common pipistrelle. The fact that we hardly ever hear their sounds means they must hear ours all the time. The CD makes you wonder how our noise interferes with the animals.
There's an alarming example in a recent study of the wild soundscape by Bernie Krause, "The Great Animal Orchestra". In Mono Park in California, spadefoot toads—a dull-brown species with bulging eyes—use synchronous choruses as a mechanism of self-defence. If they all make the same noise at the same frequency at the same time, predators can't identify where the individuals are. Krause writes about the effect on the toads of the sound of a jet flying four miles away. The low rumble interrupted the toads, making it impossible for them to keep time with one another. The consequences were devastating. "It took some time," Krause writes, "for the toads to re-establish their protective acoustic connection—from 35 to 40 minutes after the noise had faded—and under a bright moonlit sky, my wife and I watched from our nearby campsite as a pair of coyotes and a great horned owl swept in to pick off a few toads during their attempt to re-establish vocal synchronicity."