By studying bat migratory patterns in Nebraska we will help utility companies, wind energy developers, and wind facility owners avoid, manage, and mitigate the effects of new and existing wind energy facilities.
Bats provide critical ecosystem services across the globe, ranging from pollination and seed dispersal to insect control. In the United States, all bats are insectivorous and consume up to twice their body weight in insects every night. Their voracious appetite is estimate to replace at least $3.7 billion dollars in pesticide use across the U.S., saving farmers $74 per acre. Preserving bat populations is important for both the ecosystem and the humans who rely on the services they provide.
Unfortunately, the cumulative impacts of opportunistic wind energy development could have unanticipated, negative consequences in Nebraska and around the nation. Already, wind turbines kill an estimated 800,000 bats annually. As the energy sector positions itself to harness Nebraska’s wind resources, we must consider and minimize the unintended consequences to Nebraska agriculture and natural resources. Potential negative impacts of wind energy development on bats can be minimized through siting and operations that consider bat presence, activity, and movement.
To achieve our goal, we are using 3 methods. First, we are using bat detectors to identify when and where bats are moving in eastern Nebraska, throughout the year. These detectors record the ultrasonic acoustic signals bats use to navigate and allow us to determine the species present and activity levels at recording locations. Starting in 2014 we placed acoustic detectors on silos and grain bins around East–Central Nebraska. Currently, there are 21 detectors recording from March to November. The data are being used to identify the timing of bat migration in the area and to create a spatial map of bat activity, allowing us to determine if any migratory corridors exist in the area. Second, a separate acoustic grid of more than 50 detectors will be placed along the Missouri River floodplain during the fall migratory period to determine if and how the river and bluff lines are being used during migration. Finally, bats are being captured in order to collect fur samples. The isotope levels from these samples will help us determine the migratory period and the catchment area of migratory bats.
Information gathered will be used to further promote sound resource management practices, especially by informing new wind energy facilities of high risk areas and help all facilities identify times of greatest threats to bats. Partners on this project include the Nebraska Wind Energy and Wildlife Project, the U.S. Fish and Wildlife Service, the Nebraska Game and Parks Commission, and the University of Nebraska–Lincoln.