PARIS – Windmills now act as the top "predator" in some ecosystems, causing damage to birds at the top of the food chain and causing a knock-on effect that is often neglected by green energy advocates, scientists said on Monday.
The wind is the fastest growing sector of renewable energy, which supplies about 4 percent of the world's demand for electricity.
Nearly 17 million hectares – an area about the size of Tunisia – is currently used to produce wind energy around the world, and researchers have warned that developers have "greatly underestimated" the impact of technology on wildlife.
In a new study, the international team of scientists studied the impact of the use of a wind turbine in Western Ghats, a series of mountains and forests mentioned in UNESCO that stretches on the west coast of India and the global "focal point" of biodiversity.
They found that the birds of raptor plunder were four times smaller in the plateau regions where there were wind farms, a disorder that cascaded down the food chain, and radically altered the density and behavior of the prey.
The team watched in particular the explosion in a favorite meal of fishermen – contaminated lizards – in areas dominated by turbines.
In addition, they saw significant changes in the behavior and appearance of the lizard, living as if they were essentially an environment without predators.
"What we have been extremely subtle changes in the behavior, morphology and physiology of these lizards," said Maria Thaker, assistant professor at the Indian Institute of Science Center for Environmental Sciences and lead author of the study.
As raptor levels fell around the turbine, the degree of predatory attacks on the lizard had to be dealt with.
As a result, the team found that lizards living in wind farms and around them reduced the alertness from possible dangers.
Simulating "predator attacks", people in the studio could be closer to the lizard in the zones of the wind farms up to five times than those who lived far from the turbine before the creatures escaped.
After testing, lizards near the turbine showed that they had a lower level of stress hormone – something that must have occurred in two decades since wind farms were built in western Ghats.
It is known that wind farms are detrimental to birds, disrupting their migration patterns and causing them to exceed the average mortality rate.
Thaker said that her research, published in Nature Ecologi & Evolution, showed that wind turbines replicated the role of a top-level predator in the food chain, holding the raptors in the bay.
"They trigger changes in the equilibrium of animals in the ecosystem as if they are the most important predators," she said.
"They are" predators "of raptors – not in terms of killing them, but by reducing the presence of raptors in these areas."
As carbon emissions from people continue to grow, Thaker said that wind energy is vital for mitigating the effects of climate change.
However, with the evidence that the impact of wind farms on Earth's ecosystems is far reaching than previously thought, it called for greater consideration of the impact of a vital energy source on the environment.
"It took decades for scientists to understand that wind turbines adversely affect animals that fly," Thaker said.
"We need to be smart about how green energy solutions are distributed. Let's reduce our impact on the planet and put turbines in places that are somehow upset – on buildings for example."