Wind Farms Act Like Apex Predators on Ecosystems, Study Finds

At a Glance

• The study in India found birds of prey were being killed by wind turbines.
• It also found that the population of lizards the birds ate grew dramatically.
• The scientists discovered the lizards had less of a stress hormone in their blood.

Scientists have long known that wind farms and wind turbines kill birds — even if they disagree over the total number and how that compares to deaths caused by other energy sources.

Now, a new study has gone beyond the bird deaths to look at what happens further down the food chain if the predatory birds are no longer a big threat.

The study, published Monday in Nature Ecology and Evolution, says wind farms could have greater ecological consequences than previously thought.

A team of scientists from the Indian Institute of Science in Bangalore set up the study in the Western Ghats, a range of mountains and forests that runs along India's west coast and is considered a global "hotspot" of biodiversity.

Wind turbines have been operating for 16 to 20 years in parts of the Ghats, Yale Environment 360 writes

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The scientists compared the wind farms with areas in the nearby Sahyadri Tiger Reserve and Koyna Wildlife Sanctuary, where turbines are not allowed, according to Tech Explorist.

They found that predatory birds, like raptors and buzzards, were four times rarer near wind turbines than in areas without them.

The wind farms "trigger changes to the balance of animals in an ecosystem as if they were top predators," Maria Thaker, assistant professor at the institute's Centre for Ecological Sciences and lead study author, told AFP. "They are the 'predators' of raptors – not in the sense of killing them, but by reducing the presence of raptors in those areas."

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Looking further down the food chain, the team found that the lack of birds dramatically altered the density and behavior of the birds' prey.

The population of the birds' favorite food, fan-throated lizards, exploded.

The population of fan-throated lizards boomed in areas around wind farms.

(Indian Institute of Science/Abi Vanak)

"What was remarkable to us were the subtle changes in behavior, morphology and physiology of those lizards," Thaker said.

The lizards, not having to worry so much about being attacked anymore, were less vigilant. They let humans get much closer to them than the lizards that didn't live near wind turbines.

The turbine-area lizards also had less of the stress hormone, corticosterone, in their blood.

"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 wrote in the study.

The study stressed that the findings aren't a reason to stop wind development. However, the scientists said, the environmental consequences should be taken into account, along with economic considerations when deciding where to locate wind farms.

https://weather.com/news/news/2018-11-05-predator-birds-wind-turbines-lizards