TY - THES
TI - Bat Behavior at Commercial Wind Turbines as Revealed by 3-D Thermal Videography
AU - Aghababian, S
AB - The wind industry is rapidly growing, yet lethal interactions between bats and industrial-scale wind turbines remain an ecological drawback of this valuable renewable energy source. Previous research has utilized two-dimensional video to describe bat behavior, however it is unable to provide quantifiable spatial metrics that may be important in determining why collisions occur and inform development of collision minimization systems. Our study represents the first utility-scale application of three dimensional video, a method capable of accurately measuring the position of animals in space, used to measure bat activity patterns at commercial wind turbines. We reconstructed 22,479 flight paths of nocturnal aerial animals across 89 recording nights at two wind turbines in a utility-scale wind energy facility in Iowa, USA between August and October of 2021. We observed 68% of vertebrate animal flights at heights within the rotor-swept zone where they are at danger of colliding with blades. Activity was 300% higher in the lower half of the rotor-swept zone (below the turbine nacelle) compared to the upper half. We found that activity within and above the rotor swept area is concentrated during a small range of dates in late August, early evening hours, and for winds blowing to the south between 3 and 6 meters per second, supporting the theory that bat mortality is related to peaks in migration activity. For a subset of 23 nights distributed across the sampling period, we manually classified the behavior of 4,252 flight paths. Linear flight behaviors were more common above the turbine, whereas non-linear behaviors were more common at altitudes in the lower rotor-swept zone. We also iv reconstructed two collisions with the turbine which suggests that wind turbulence may be a proximate cause of collision. Our findings indicate that while three-dimensional video may not be necessary for general activity studies, it will be valuable in understanding how best to deploy targeted minimization systems, such as acoustic deterrents, and provide in-depth characterizations of bat behavior near turbines that will help elucidate the underlying cause of collisions.
DA - 2023/08//
PY - 2023
PB - University of Colorado Colorado Springs
UR - https://www.proquest.com/openview/1713cfd7c61b8d851a23d704c5e9304a/1?pq-origsite=gscholar&cbl=18750&diss=y
LA - English
M3 - Master's Thesis
KW - Wind Energy
KW - Collision
KW - Bats
ER -