PARIS – Wind farms now act as a leading "predator" in some ecosystems, damaging birds at the top of the food chain and triggering a blow-off effect often neglected by green energy advocates, scientists said on Monday.
Wind is the sector with the highest growth of renewable energy, providing about 4% of global electricity demand.
Nearly 17 million hectares, an area roughly the size of Tunisia, are currently used to generate wind energy worldwide, and researchers have warned that developers have "greatly underestimated" the impact that technology has on wildlife.
In the new research, an international team of scientists has studied the effects of wind turbine use in the West Ghats, a range of UNESCO-listed mountains and forests that find the coastal region of India and a global "hotspot" of biodiversity.
They found that prey birds were four times as rare in the plateau areas where wind turbines were present, a disturbance that stabbed the food chain and radically altered the bird's density and behavior.
In particular, the team noticed an explosion in the raptor's favorite male – flowering lizards – in areas dominated by turbines.
In addition, they have seen significant changes in the behavior and appearance of lizards, living as if they were in an essentially predatory environment.
"What was remarkable for us was the subtle change in the behavior, morphology and physiology of these lizards," said Maria Thaker, an assistant professor at the Center for Ecological Sciences at the Institute of Ecological Sciences in India and the lead author of the study.
Because the kidnapper levels fell around the turbines, so was the rate of the predatory attacks they had with the lizards.
As a result, the team found that lizards living in and around wind farms have reduced their vigilance against possible dangers.
By simulating "predatory attacks," the people in the study could get up to five times closer to a lizard in wind farms than one lived away from the turbines before the creatures run away.
After testing, the lizards near the turbines were found to have lower levels of a stress hormone – something that emerged in the two decades since wind farms were built in Western Ghats.
Wind farms are known to be detrimental to birds, disturbing their patterns of migration and causing death rates above average.
Thaker said his research, published in the journal Nature Ecology & Evolution, showed that wind farms have replicated the role of the predator in the food chain by keeping the raptors in place.
"They trigger changes in animal equilibrium in an ecosystem as if they were top predators," she said.
"They are the" predators "of the kidnappers – not in the sense of killing them, but by reducing the presence of the kidnappers in those areas."
As man-made carbon emissions continue to grow, Thaker said wind power is vital to mitigating the effects of climate change.
But with evidence that the impact of wind farms goes further into the Earth's ecosystems than previously thought, it has called for more attention to the environmental impact of the vital green energy source.
"It took decades for scientists to realize that wind turbines negatively affected the flying animals," Thaker said.
"We need to be intelligent about how we implement green energy solutions. Reduce our footprint on the planet and put turbines in places that are already disturbed somehow – for example on buildings."