For those of you who aren’t already familiar with him, introducing the Lyrebird – impersonator extraordinaire.
The effects of human made noise on wildlife is nigh on impossible to accurately gauge. The range and intensity of responses exhibited by animals to our many cacophonous engagements is too varied to draw any concrete conclusions. Policy makers are paralysed to do anything, the public is unconvinced that its noisy activities can seriously affect wildlife and scientists lose faith in their ability to prove what some already know through intuition.
These are the principle conclusions from Autumn Lyn Radle’s 2007 article, “The Effect of Noise on Wildlife: A Literature Review. And what frustrating conclusions they are, the kind that compel this blogger to consider making this academic article the last he ever reads. But then, it’s not Radle’s fault. Nor is it the fault of the scientists whose largely inconclusive studies constitute the subject matter of Radle’s aggregation of largely inconclusive studies. Least of is it the animals’ fault. They can’t help inhabiting environments where countless factors dictate towards behavioural and physiological traits, making it difficult to ascertain which factor contribute towards which traits, and whether human noise is a significant one.
So we know very little about how man-made sound affects wildlife. But we do know some things. We know that man-made sound has more sources than we might initially think. As well as the obvious – recreational noise from motorboats
Recreational boating is a key noise culprit
or holidaymakers; military noise; and commercial noise from airplane flyovers, mining operations and logging – there is also evidence that scientific research (usually with the intention of assisting wildlife) is in some cases noisy enough to pose a possible threat to some species.
We also know that noise can be hugely detrimental to humans. Look at the case of Cairo, a city where the average noise level between the hours of 7am and 9pm is 85 decibels – just louder than a freight train passing by 5 metres away. Of the city’s 7 million inhabitants, two-thrids are estimated to suffer from some sort of sleeping disorder. Indeed, the city has just opened its first sleep clinic, the first state-sanctioned one in the world.
But regardless of the current state of knowledge, knowledge isn’t necessary for action. Our reluctance to act on this issue due to a lack of concrete evidence is proof in itself of our anthropocentric worldview. If we took a view more sympathetic to the rest of the living biosphere we would, in Radle’s words, “intuitively understand that a cacophony of noise, even if not life threatening, cannot provide for a decent quality of life for any organism”. These words have a certain resonance to them. Since the advent of the Industrial Age our actions have caused sometimes irreversible damage – to our landscapes, waterways and atmosphere. In those cases, much of the damage was done before we had proof that any damage was being done. While the evidence is not concrete, intuition provides a valuable clue here. If we pay heed to it, we may be able to stop the relentless advance of man-made noise before its effects on the biosphere begin to resemble those other horrors.
A friend and colleague of mine, Tess bunny, runs a wonderful blog called Wild the City. She talks about ways that we can enhance city landscapes, soundscapes, biodiversity and manage the ever-increasing disconnect between the natural world and our everyday urban experiences.
In a post she writes about her experience living in Dunedin:
For me, living in Dunedin, the most powerful story I’ve heard about the area is that people could not sleep at night due to the sound of whales in the harbour. Only 200 years ago they were kept awake all night by the whales spouting, calling and moving. It is a sad reality that today we don’t hear or see any whales in the harbour.
This degradation of the urban soundscape is a recurring theme in her work and something that I will be exploring in depth in the next few weeks as I help Tess put together an audio-visual installation she’s running between July 6th and 11th. The installation will be housed in one of Dunedin’s blandest, most sterile destinations, the Meridian shopping centre, in attempt to raise awareness of these issues.
As well as discussing the issues that Tess is addressing, I’ll also be putting together some podcasts documenting our experiences collecting sounds from the Dunedin environs; details of and public reaction to the installation itself; and a stream of the audio portion of the project.
So stay tuned.
One of the crucial factors in Bernie Krause’s formulation of the Niche Hypothesis and in his sometimes dire predictions about the decline of natural soundscapes is the benefit afforded by many years of close listening to soundscapes. Long-term listening, just like long-term observation, can reveal things that a cursory examination can not.
This is exactly the idea that drives the Muskegon River Watershed project, a joint initiative aimed at measuring the biodiversity of the Muskegon River over a long period of time. The project was set up by Stuart Gage of Michigan State University, along with Bryan Pijanowski of Purdue. Together, they deployed solar powered microphones at specific points throughout the region. Recordings are relayed to the scientists via satellite and are logged and entered into the database. At the end of the project, the recordings will be compared and conclusions will be drawn regarding the long-term health of the region.
Another ecologist with similar ideas about the usefulness the aural examination of natural processes over the long-term is Almo Farina of Italy’s Urbino University. He studies the relationship between bird activities and the surrounding landscape by examining recordings made from a selection of microphones strewn across a valley floor by a cable car. His findings are in accord with the Niche Hypothesis. He states that “some birds sing only after another species becomes silent, and vice versa”. This indicates a natural give and take, exactly as Krause describes. He explains further, that “when you find acoustic overlap, this means that the community could be affected by some habitat disturbance”.
Both of these projects allow a completely fresh perspective on the health of natural environments and allow scientists to asses long-term affects of human activities on these environments. They also reinforce the importance and effectiveness of holistic approaches to studying natural soundscapes. They indicate a need for us avoid the tendency to focus in on particular sounds, a habit which only contributes to a warped impression of the soundscapes we find ourselves amidst. The sound of Tui or a Bellbird may be lovely, but if we ignore their increasing irregularity, we may stand to lose them in future.