Skip to main content
U.S. flag

An official website of the United States government

Fatalities at wind turbines may threaten population viability of a migratory bat

Formally Refereed
Authors: W.F. Frick, E.F. Baerwald, J.F. Pollock, R.M.R. Barclay, J.A. Szymanski, Ted Weller, A.L. Russell, Susan Loeb, R.A. Medellin, L.P. McGuire
Year: 2017
Type: Scientific Journal
Station: Pacific Southwest Research Station
Source: Biological Conservation. 209: 172-177


Large numbers of migratory bats are killed every year at wind energy facilities. However, population-level impacts are unknown as we lack basic demographic information about these species. We investigated whether fatalities at wind turbines could impact population viability of migratory bats, focusing on the hoary bat (Lasiurus cinereus), the species most frequently killed by turbines in North America. Using expert elicitation and population projection models, we show that mortality from wind turbines may drastically reduce population size and increase the risk of extinction. For example, the hoary bat population could decline by as much as 90% in the next 50 years if the initial population size is near 2.5 million bats and annual population growth rate is similar to rates estimated for other bat species (λ = 1.01). Our results suggest that wind energy development may pose a substantial threat to migratory bats in North America. If viable populations are to be sustained, conservation measures to reduce mortality from turbine collisions likely need to be initiated soon. Our findings inform policy decisions regarding preventing or mitigating impacts of energy infrastructure development on wildlife.


Expert elicitation, hoary bat, Lasiurus cinereus, population viability, wind energy


Frick, W.F.; Baerwald, E.F.; Pollock, J.F.; Barclay, R.M.R.; Szymanski, J.A.; Weller, T.J.; Russell, A.L.; Loeb, S.C.; Medellin, R.A.; McGuire, L.P. 2017. Fatalities at wind turbines may threaten population viability of a migratory bat. Biological Conservation. 209: 172-177.