The impact of wind farms on local ecosystems can cascade down the food chain, causing indirect impacts on lower-level animals as if turbines were new apex predators, reports a paper published online this week in Nature Ecology & Evolution.
Previous studies have shown evidence that wind farms can reduce the local numbers of birds and bats, disrupt bird migration routes and decrease the densities and activities of land mammals. However, it is often assumed that wind turbines’ greatest impacts are confined to flying species.
Maria Thaker and colleagues investigated wildlife on the mountain plateaus of India’s Western Ghats and found that the ecological impact of wind farms reaches further into the community than was previously thought. The authors observed almost four times more predatory birds in areas without wind turbines than around wind-farms. They found more lizards around wind farms, which the authors attribute there being fewer predatory bird attacks in these areas. These lizards also had lower levels of the stress hormone corticosterone and allowed people to get closer before fleeing, which may be signs that they experience less predation.
The authors suggest that wind farms act like an additional level at the top of the food chain, resulting in a cascading effect on nearby animals. Although wind farms are an essential source of renewable energy, the authors suggest that their effect on the local ecology must be taken into account when determining where turbines should be located.