Research focused on golden eagles in Wyoming
FRISCO — Federal scientists say a new modeling study will help more accurately predict bird deaths at wind energy sites before they’re built.
The findings could help planners design more bird-friendly wind power facilities — important because by the best available estimates, the spinning turbines kill between 160,000 and 330,000 birds each year, and that number is likely to grow as the number and size of wind turbines increases.
The research by the U.S. Geological Survey and the U.S. Fish and Wildlife Service used golden eagles as a case study because they are susceptible to collisions with wind turbines in part because of their soaring and hunting behavior.
The model looks at only three parameters: hazardous footprint, bird exposure to turbines and collision probability.
“This simplicity is part of what makes the model accessible to others,” said Leslie New, assistant professor of statistics at Washington State University, who led the research project as a USGS postdoctoral fellow. “It also allows wind facility developers to consider ways to reduce bird fatalities without having to collect a complicated set of data.”
Not every wind power facility is a killing field for birds. The mortality rate depends on the exact location, the types of birds in the area and other site-specific factors.
The case study looked closely at golden eagle fatalities at a Wyoming wind facility. The long-lived birds reproduce slowly, so wind turbine fatalities have potential population-level effects, and because golden eagles are protected by law, the permitting process requires that fatality predictions be made in advance of a wind facility’s construction.
The article, “A collision risk model to predict avian fatalities at wind facilities: an example using golden eagles, Aquila chrysaetos” by L.F. New, E. Bjerre, B. Millsap, M. Otto and M. Runge, is available in PLOS ONE online.