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Behavioral Responses of Bats to Operating Wind Turbines
Author(s) -
HORN JASON W.,
ARNETT EDWARD B.,
KUNZ THOMAS H.
Publication year - 2008
Publication title -
the journal of wildlife management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.94
H-Index - 111
eISSN - 1937-2817
pISSN - 0022-541X
DOI - 10.2193/2006-465
Subject(s) - foraging , wind power , turbine , environmental science , wind speed , marine engineering , climbing , meteorology , aeronautics , aerospace engineering , ecology , geography , engineering , biology
Wind power is one of the fastest growing sectors of the energy industry. Recent studies have reported large numbers of migratory tree‐roosting bats being killed at utility‐scale wind power facilities, especially in the eastern United States. We used thermal infrared (TIR) cameras to assess the flight behavior of bats at wind turbines because this technology makes it possible to observe the nocturnal behavior of bats and birds independently of supplemental light sources. We conducted this study at the Mountaineer Wind Energy Center in Tucker County, West Virginia, USA, where hundreds of migratory tree bats have been found injured or dead beneath wind turbines. We recorded nightly 9‐hour sessions of TIR video of operating turbines from which we assessed altitude, direction, and types of flight maneuvers of bats, birds, and insects. We observed bats actively foraging near operating turbines, rather than simply passing through turbine sites. Our results indicate that bats 1) approached both rotating and nonrotating blades, 2) followed or were trapped in blade‐tip vortices, 3) investigated the various parts of the turbine with repeated fly‐bys, and 4) were struck directly by rotating blades. Blade rotational speed was a significant negative predictor of collisions with turbine blades, suggesting that bats may be at higher risk of fatality on nights with low wind speeds.