Timing and Weather Offer Alternative Mitigation Strategies for Lowering Bat Mortality at Wind Energy Facilities in Ontario

Kelly A Squires; Bethany G Thurber; J Ryan Zimmerling; Charles M Francis

doi:10.3390/ani11123503

Timing and Weather Offer Alternative Mitigation Strategies for Lowering Bat Mortality at Wind Energy Facilities in Ontario

Animals (Basel). 2021 Dec 8;11(12):3503. doi: 10.3390/ani11123503.

Authors

Kelly A Squires¹, Bethany G Thurber², J Ryan Zimmerling³, Charles M Francis⁴

Affiliations

¹ Tau Ecology Research Services, Courtenay, BC V9N 0C8, Canada.
² Canadian Wildlife Service, Environment and Climate Change Canada, 4905 Dufferin St., North York, ON M3H 5T4, Canada.
³ Canadian Wildlife Service, Environment and Climate Change Canada, 351 St. Joseph Boulevard, Gatineau, QC K1A 0H3, Canada.
⁴ Canadian Wildlife Service, Environment and Climate Change Canada, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.

Abstract

Relatively high mortality of migratory bats at wind energy facilities has prompted research to understand the underlying spatial and temporal factors, with the goal of developing more effective mitigation approaches. We examined acoustic recordings of echolocation calls at 12 sites and post-construction carcass survey data collected at 10 wind energy facilities in Ontario, Canada, to quantify the degree to which timing and regional-scale weather predict bat activity and mortality. Rain and low temperatures consistently predicted low mortality and activity of big brown bats (Eptesicus fuscus) and three species of migratory tree bats: hoary bat (Lasiurus cinereus), eastern red bat (L. borealis), and silver-haired bat (Lasionycteris noctivagans). Bat activity occurred in waves with distinct peaks through the season; regardless of seasonal timing, most activities occurred in the first half of the night. We conclude that wind energy facilities could adopt a novel and more effective curtailment strategy based on weather and seasonal and nocturnal timing that would minimize mortality risks for bats while increasing the opportunities for power generation, relative to the mitigation strategy of increasing cut-in wind speed to 5.5 m/s.

Keywords: Eptesicus fuscus; L. cinereus; Lasionycteris noctivagans; Lasiurus borealis; bat activity; eastern red bat; hoary bat; mortality; silver-haired bat; southwestern Ontario.