Predicting bird and bat fatality risk at wind farms and proposed wind farm sites using acoustic-ultrasonic recorders
The USGS and University of Minnesota collaborators used acoustical and ultrasonic recorders to monitor flight notes of birds and calls emitted by bats flying at low elevations. Recorders were deployed in conjunction with ongoing fatality searches at wind facilities and at sites with a variety of landscape features. Objectives are to determine whether the recorders can be used to compare low-elevation flight activity among sites, and to relate recorder results to numbers of dead birds and bats found at wind facilities. The U.S. Fish and Wildlife Service joined the partnership to deploy the recorders at numerous locations along the shores of several Great Lakes to estimate low-elevation flight activity of birds and bats, especially during migration periods, at sites where wind development appears likely. The use of airspace by flying animals provides the nexus between wind farms and the fatalities they cause. A wind farm located where few animals fly is likely to result in few if any fatalities. Conversely, a wind farm located where flight activity by animals is intensive may pose severe risks to those animals. Accordingly,
knowledge of airspace use is fundamental for assessing risks of wildlife development to wildlife. A proposed study would evaluate the potential various tools for determining the intensity of low-elevation flight of birds, bats, and other flying animals. Information derived from use of such tools could be used in combination with knowledge of wind resources and likely wind development sites to facilitate the assessment of wind development effects on wildlife.
Douglas H Johnson