No birdsong, no water in the creek, no beating wings: how a haven for nature fell silent

Bernie Krause ‘out there and listening to the soundscapes’ in Sugarloaf Ridge state park. Photograph: Cayce Clifford/The Guardian

As the soundscape of the natural world began to disappear over 30 years, one man was listening and recording it all

The tale starts 30 years ago, when Bernie Krause made his first audio clip in Sugarloaf Ridge state park, 20 minutes’ drive from his house near San Francisco. He chose a spot near an old bigleaf maple. Many people loved this place: there was a creek and a scattering of picnic benches nearby.

As a soundscape recordist, Krause had travelled around the world listening to the planet. But in 1993 he turned his attention to what was happening on his doorstep. In his first recording, a stream of chortles, peeps and squeaks erupt from the animals that lived in the rich, scrubby habitat. His sensitive microphones captured the sounds of the creek, creatures rustling through undergrowth, and the songs of the spotted towhee, orange-crowned warbler, house wren and mourning dove.

As the soundscape of the natural world began to disappear over 30 years, one man was listening and recording it all

Back then, Krause never thought of this as a form of data-gathering. He began recording ecosystem sounds simply because he found them beautiful and relaxing. Krause has ADHD and found no medication would work: “The only thing that relieved the anxiety was being out there and just listening to the soundscapes,” he says.

Inadvertently, he had begun to gather a rich trove of data. Over the next three decades he would return each April to the spot at the bigleaf maple, set his recorder down and wait to hear what it would reveal.

But in April last year, Krause played back his recording and was greeted with something he had not heard before: total silence. The recorder had run for its usual hour, but picked up no birdsong, no rush of water over stones, no beating wings. “I’ve got an hour of material with nothing, at the high point of spring,” says Krause. “What’s happening here is just a small indication of what’s happening almost everywhere on an even larger scale.”

Animals produce a vast array of sounds: to find mates, protect territories, identify offspring or simply by moving about. But traditionally, ecologists have measured environmental health by looking at habitats rather than listening to them. Krause developed the idea that the sound of healthy ecosystems contained not only the calls of individual animals, but a dense, structured weave of sounds that he called the “biophony”.

In 2009, when Krause listened through his archive, he realised a story was emerging: a subtle but noticeable loss in the density and variety of natural sounds.

At the same time, he began observing odd things happening in Sugarloaf Ridge park. Leaves on some tree species were unfurling two weeks earlier than documented in historical records. The change in bloom meant migrating birds […]

Full article: www.theguardian.com