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In Support of the U.S. Fish and Wildlife Service 3-Bat Species Status Assessment: Predicted Wind Take Allocated To Hibernacula Each Year Under Current and Future Scenarios

May 26, 2021

Through the North American Bat Monitoring Program (NABat), United States Geological Survey (USGS) provided technical and science support to assist in U.S. Fish and Wildlife Services’ (USFWS) Species Status Assessment (“SSA”) for the northern long-eared bat (Myotis septentrionalis), little brown bat (Myotis lucifugus), and tri-colored bat (Perimyotis subflavus). USGS facilitated the SSA data call, provided data archival for repeatable and transparent analyses, provided statistical support to assess the historical, current, and future population status for each of the three species, and developed a demographic projection tool to evaluate future viability of each species under multiple threat scenarios.

These data represent the predicted bat take from wind energy allocated to each known winter hibernacula (at the resolution of the NABat grid cell) for each species, under several scenarios. These annual wind take predictions for each hibernacula and scenario were produced as inputs for a separate demographic scenario modeling effort (Wiens et al. 2021) in support of the U.S. Fish and Wildlife Services’ 3-Bat SSA. The predicted take allocated each year to each hibernacula was dependent on: 1) current or future distribution of wind energy on the landscape, 2) the curtailment status (none, summer only, summer and fall) of current wind energy facilities, 3) mortality rate (take/megawatt of rated capacity), under lower (25th percentile), mean, and upper (75th percentile) scenarios based on estimates provided by USFWS, 4) the predicted year of arrival of Pd (Pseudogymnoascus destructans) for each location based on 2 alternative models which used data from the county-level USGS pd surveillance map, 5) the species' proportion of all bat take in each USFWS region and Canadian province, based on estimates provided by USFWS (both before and after the arrival of Pd), 6) the mean and maximum migration distances of each species, 7) the last observed count of each hibernacula, 8) the distance between each hibernacula and wind energy location, and 9) an exponential migration kernel (distance decay function) based on the mean migration distance of each species. The total take at each wind energy grid cell was predicted based on items 1-5, and take was reallocated among hibernacula given items 6-9. Scenario levels included 4 time periods (current, 2030, 2040, 2050), 2 alternative pd spread models, 2 future wind energy development scenarios (high cost = low future build-out, low cost = high future build out) using models provided by the National Renewable Energy Lab (NREL), and 3 scenarios for take/megawatt estimates (mean, 25th percentile,75th percentile), for a total of 42 scenarios for each species.