A new study released by the U.S. Geological Survey on July 13 suggests that five of 14 species of raptors have the potential for population-level impacts from increased wind energy development while an additional three species were inconclusive on potential risk. According to the study’s abstract, “Projections of current levels of fatalities to future wind energy scenarios at 241 GW of installed capacity suggest some species could experience population declines because of turbine collisions. Populations of those species may benefit from research to identify tools to prevent or reduce raptor collisions with wind turbines.”

Scientists used existing fatality data on collisions with wind turbines to project population structures of each raptor species and future fatalities from the current national capacity of around 100 gigawatts to about 240 gigawatts. The raptor species included in the study had sufficient population information available for the modeling exercise.

Researchers found that barn owls, ferruginous hawks, golden eagles, American kestrels, and red-tailed hawks were at the highest risk for collisions with wind turbines. While not listed as endangered or threatened, all of those species except red-tailed hawks are experiencing declines unrelated to wind energy development. The researchers also found that burrowing owls, Cooper’s hawks, great horned owls, northern harriers, osprey, and turkey vultures showed low potential impacts from both current and forecasted wind energy development while merlins, prairie falcons, and Swainson’s hawks, could not be conclusively categorized for risk. USGS notes that raptors live longer than most birds, take longer to reach adulthood and have fewer offspring, making these populations more reliant on adults surviving for longer periods and the impact of wind turbines greater on the population.

“With more wind turbines, there will be a greater need to mitigate impacts from energy production on wildlife species,” observed USGS research ecologist Jay Diffendorfer who authored the study that was published in Ecosphere. “This paper provides an initial attempt to prioritize species for which mitigation may be most influential.”