Wildlife Mortality at Wind Facilities: How We Know What We Know How We Might Mislead Ourselves, and How We Set Our Future Course

  • Manuela HusoEmail author


To accurately estimate per turbine – or per megawatt – annual wildlife mortality at wind facilities, the raw counts of carcasses found must be adjusted for four major sources of imperfect detection: (1) fatalities that occur outside the monitoring period; (2) carcasses that land outside the monitored area; (3) carcasses that are removed by scavengers or deteriorate beyond recognition prior to detection; and (4) carcasses that remain undiscovered by searchers even when present. To accurately estimate regional or national annual wildlife mortality, data must come from a representative (or appropriately weighted) sample of facilities for which estimates of mortality account for all sources of imperfect detection. I argue that the currently available data in the United States and much of the world do not represent the impacts of wind power on wildlife because not all facilities conduct monitoring studies, not all study results are publicly available, and few studies adequately account for imperfect detection. I present examples illustrating the limitations of our current data and pitfalls of interpreting data without accurately adjusting for detection bias. I close by proposing a solution through a simplified monitoring process that can be applied at every facility as part of normal operations. Application of an unbiased estimator that accounts for all sources of imperfect detection would assure comparability of mortality estimates. Public access to reported estimates would achieve representation. With these data we could develop a clearer understanding of how wind power is affecting wildlife throughout the world and inform our efforts to address it.


Representative Spatial distribution Road and pad searches R&P Detection probability 



I thank the organizing committee of the Conference on Wind Wildlife for inviting me to give this talk and supporting my travel. I thank Fränzi Korner-Nievergelt, Mona Khalil, and an anonymous reviewer for helpful suggestions to improve the manuscript. I thank Dan Dalthorp, Guillaume Marchais, Cris Hein, Michael Schirmacher, and Jerry Roppe, for many fruitful discussions regarding the feasibility of road and pad searches, but do not wish to imply any endorsement on their part of the ideas I present here. Funding for this research was provided by the Ecosystems Mission Area Wildlife Program of the US Geological Survey (USGS). Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the US Government.


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© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.US Geological SurveyCorvallisUSA

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