An apex predator is defined as a predator with no natural predators. People, lions, killer whales, and bears are typical examples. Now we can add one more to the list: wind turbines. Research indicates that in the U.S. alone, wind turbines are responsible for killing more than half a million birds every year. More than 80,000 of those birds are raptors, the former apex predators of the air.
While China and the U.S. lead the world in the amount of power generated by wind farms, India is not too far behind. As a result, a group of researchers from the Indian Institute of Science decided to study the ecological impacts of wind turbines. They analyzed turbines that have been installed in an Indian Mountain Range called the Western Ghats. Some of those wind turbines are pictured above. Specifically, they wanted to see if the predatory nature of wind turbines had other effects on the local ecosystem. Not surprisingly, it did.
First, they found that predator birds were four times less likely to be in the areas where wind turbines are installed compared to areas where they are not installed. That’s not surprising. Animals tend to avoid areas where they are preyed upon. Of course, the opposite is true as well. Animals tend to flock to places where they will not be preyed upon. As a result, the population of fan-throated lizards (a favorite meal of predator birds in the area) is significantly higher around wind turbines.
Interestingly enough, the effect of wind turbines was not limited to populations. The lizards’ behavior changed as well. Apparently, life is so carefree for the lizards living near the wind turbines that they have lost some of their fear of predators in general. The researchers tried to simulate predator attacks and found that they could get significantly closer to lizards that live near the wind turbines than they could get to lizards living where there are no wind turbines. Based on subsequent blood tests, the researchers concluded that lizards living near wind turbines have significantly less corticosterone (a stress hormone) in their blood.
So in the end, the ecological effect of wind farms goes beyond the slaughter of birds (and bats). It “trickles down” the food chain as well. The authors say:
By adding an effective trophic level to the top of food webs [by being an apex predator], we find that wind farms have emerging impacts that are greatly underestimated. There is thus a strong need for an ecosystem-wide view when aligning green-energy goals with environment protection. (bracketed statement mine)
I predict that as more research is done, we will see many more unexpected ecological effects from wind farms.