EXPRESS #4 - November 13, 2018
Wind farms may turn out to be far more deadly than we may have realised so far.
In a new study, published in the journal Nature & Ecology Evolution, ecologists from the Indian Institute of Science in Bangalore, looked at how wind farms in India’s Western Ghats, which have been operating for 16 to 20 years, impacted species throughout the food chain.
They found almost four times more birds of prey in areas without turbines. Meanwhile, they found more lizards living in wind farms than elsewhere. These lizards also had lower levels of corticosterone, a stress hormone, and allowed researchers to get closer before running away than in areas without turbines.
“By reducing the activity of predatory birds in the area, wind turbines effectively create a predation-free environment that causes a cascade of effects on a lower trophic level,” the scientists write.
Although they stress that their research shouldn’t be seen as a reason to stop wind development, they do add that “since the locations of wind farms are mainly determined based on economic rather than environmental considerations… the consequences of wind farms are greatly underestimated.”
As a result, wind farms located in areas rich in biodiversity “illustrate an unexpected conflict between the goals from the United Nations Paris Agreement for climate change mitigation and Aichi Biodiversity Targets from the Convention on Biological Diversity.”
All of this is very polite language for what seem to be alarming conclusions. Wind farms already have a reputation for killing large birds, such as eagles. This reputation is now borne out by what seems an incontrovertible study.
The Daily Mail summarized the conclusions of the researchers in somewhat blunter terms: “Wind turbines are the world’s new ‘apex predators’, wiping out buzzards, hawks and other carnivorous birds at the top of the food chain, say scientists. A study of wind farms in India found that predatory bird numbers drop by three quarters in areas around the turbines. This is having a ‘ripple effect’ across the food chain, with small mammals and reptiles adjusting their behaviour as their natural predators disappear from the skies. Birds and bats were assumed to be most vulnerable to the rise of the landscape-blotting machines. But their impact is reverberating across species, experts warned, upsetting nature’s delicate balance. The news is particularly worrying as most wind farms are built on wide open plains and other environments where birds are typically found.”
In an article on the popular website for academic researchers, The Conversation, Jeroen Minderman, Research Fellow at the University of Stirling in the UK, tries to moderate the conclusions of the Indian scientists somewhat – but does he succeed? I don’t think so.
Minderman writes that “Reams of published scientific papers show that birds and bats can be killed (sometimes in relatively large numbers) by colliding with the spinning blades. Clearly, where turbines are poorly placed or where rare or vulnerable species are affected, this is a problem. Images of dead birds of prey or rare vagrant birds under wind turbines are easily turned into emotive and sensational news stories, and are terrible PR for the wind industry.”
I would think this is not just about PR – it is about the real effects of wind farms on nature.
Minderman then says that “While it certainly is true that collision with turbines can cause direct mortality, what the new research actually shows is far more interesting and complex than this. The result of many years of data collection, the work shows that through the (direct or indirect) effects on birds of prey, wind turbines can have broader and more subtle effects on the wider ecosystem – including on some unexpected species.”
What are these “broader and more subtle effects”? Minderman concedes that “in some ways, it may indeed seem as if wind turbines act similarly to the introduction of an ‘apex predator’ into the food chain: by reducing the number and activity of intermediate predators such as birds of prey, predation pressure on smaller animals may be reduced. However, it is of course important to stress that almost all biological predators are, in the end, limited by the availability of prey. By contrast, turbines are not limited in this way and will continue to be present regardless of whether their ‘prey’ goes locally extinct.”
Excuse me? Turbines are “not limited by the availability of prey”? That is supposed to put our minds at rest?
“Perhaps more important”, Minderman adds, “is the non-lethal effects on the wider ecosystem that [are] highlighted by Thaker and colleagues. By reducing predation or reducing the activity of predators, the physiology, behaviour and population density of prey populations can be changed in unpredictable and subtle ways.”
Well, yes, but he already said that. What are those unpredictable and subtle ways, we still would like to know. And why are the non-lethal effects more important than the lethal ones?
Minderman draws the weird conclusion that “What this work really highlights is that wind farms can have effects that are indirect or not immediately visible. This poses a huge challenge for impact assessments and survey work.”
It seems to me that the work also highlights effects that are direct and immediately visible. In no way does Minderman convince me that there is not much to worry about.