Bats provide critical ecosystem services across the globe. 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.
GoalsUnfortunately, the cumulative impacts of opportunistic wind energy development could have unanticipated, negative consequences for bat populations. Across North America, wind turbines are estimated to kill over 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. 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.
To achieve this goal, we used acoustic detectors to record the echolocation calls of passing bats at locations across East–Central Nebraska. Twenty-two detectors were placed on grain legs and silos with the cooperation of private landowners and recorded from April-November 2015 and 2016. We recorded almost 1 million bat passes and identified 677,000 to species. 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. 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, we captured 72 red bats and analyzed fur isotope levels to determine the catchment areas of the species during fall migration. Isotope levels between individuals caught in the summer and during fall migration were not different. This could indicate partial or limited migratory behavior of red bats in our area.
Upcoming conclusions 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.
Project WebsiteNebraska Bat Migration Project
Principal Investigator(s)-Craig R. Allen, NE CFWRU
Graduate Student(s)-Michael Whitby, Ph.D.
Project DurationMay 2013 - June 2018
Funding-Nebraska Environmental Trust
-Nebraska Game & Parks Commission