US wind farms killed about 18.7 million bats of 28 species in 1981–2024, PNAS study finds

Between 1981 and 2024, approximately 18.7 million bats of 28 species were killed at wind farms in the United States. This follows from a study published in the journal Proceedings of the National Academy of Sciences, as reported by ua.news ua.newsua.newsua.newsOpen source ↗. By 2021, the annual figure had risen to 1.5 million bats per year ua.newsua.newsua.newsOpen source ↗. The study thus covers both the cumulative losses over the period and the growth of annual mortality.

Why the toll may be higher

The scientists explain that the actual scale of bat mortality may have been underestimated ua.newsua.newsua.newsOpen source ↗. Bat carcasses are often eaten by scavengers or get lost in tall grass, so they are not included in the statistics ua.newsua.newsua.newsOpen source ↗.

Measures to reduce bat deaths

According to the study, mortality can be reduced by carefully selecting sites for wind farm construction and by temporarily shutting down turbines during periods of bat activity ua.newsua.newsua.newsOpen source ↗. A European study of 141 wind farms showed that such measures can reduce animal deaths by more than 80% ua.newsua.newsua.newsOpen source ↗. These two measures, site selection and temporary shutdowns, are the ones named by the scientists.