How many bats die from wind turbines? The scale turned out to be much larger than expected
More than 1.5 million bats die annually from wind turbines in the USA alone. Moreover, with the development of wind energy, the number of victims is rapidly increasing.
Illustrative photo. Photo: magnific.com
Wind energy is considered one way to reduce greenhouse gas emissions. However, wind farms pose a danger to wild animals: birds and bats die from collisions with turbine blades.
However, the causes of bat deaths are still not fully understood. Scientists suggest that animals may be attracted by the noise of turbines or that they mistake tall structures for trees. It's also possible that bats do not manage to notice the rotating blades.
To ascertain the scale of the problem, as Phys.org writes, a group of scientists from the U.S. Geological Survey analyzed 499 reports of bat deaths at 277 wind farms. The observations on which these reports were based were conducted from 1996 to 2024.
However, simply summing up the found dead animals was not enough. They were searched for differently at various power stations, and some of the deceased bats went unnoticed. For example, bodies might disappear due to predators and other animals or remain hidden in tall grass.
Therefore, researchers developed a statistical model that took these circumstances into account and allowed estimating losses even at power stations where such observations were not conducted.
The results were impressive. According to estimates, from 1981 to 2024, wind farms in the continental United States could have caused the death of about 18.7 million bats of ten species.
Three species were most affected. Approximately 6.7 million deaths were attributed to hoary bats (Lasiurus cinereus), 5.8 million to eastern red bats (Lasiurus borealis), and 3.4 million to silver-haired bats (Lasionycteris noctivagans).
Moreover, with the development of wind energy, losses have sharply increased. While the number of fatalities was significantly lower in the first decades, since 2021, according to scientists' estimates, more than 1.5 million bats die annually from wind turbines.
The study authors acknowledge that, despite the use of modern statistical methods, the lack of initial data does not allow for a precise estimation of the number of bat deaths.
In addition to quantifying losses, scientists identified factors that can help reduce them. They suggest considering the peculiarities of wind turbine design and choosing locations for new power stations where the risk to bats is lower. Moreover, protective measures may vary depending on the animal species.