Wind turbines disturb prairie-chicken mating

Greater prairie-chickens have an amusing mating ritual: Males gather in groups, puff out the orange sacs on their necks, perk up feathers on their heads like little horns, and call “whooo-doo-doooh”. To best catch females’ attention, they prefer to conduct their dances on open, grassy hilltops.

Unfortunately, those areas also are ideal for wind farms. Now, a new study suggests that male prairie-chickens are more likely to abandon mating-ritual sites — called “leks” — that are very close to turbines.

The authors studied a roughly 1,300-square-kilometer patch in Kansas, made up primarily of grasslands, farms, and pastures. In 2008, a company began building a wind farm in the area. The farm contained 67 turbines, each about 90 meters tall with blades about 45 meters long. About three-quarters of the greater prairie-chicken leks in the area were within 8 kilometers of a turbine.

The team kept tabs on 23 leks from 2007 to 2011, covering the periods before and after the wind farm was built. A typical lek drew about a dozen male prairie-chickens, and males tended to return to the same leks year after year.

However, among the leks within 8 kilometers of a turbine, those closest to the turbines were less likely to be reused. From 2009-11, a lek that was at least 6 kilometers away from a turbine had more than a 95 percent chance of remaining active. In contrast, a lek less than 1 kilometer from a turbine had only a 50 percent chance.

Overall, leks within the 8-kilometer zone were nearly three times more likely to be abandoned than those outside that zone. Leks that didn’t initially draw many males or were located on farms also were more likely to dwindle.

Does this mean that wind turbines spell doom for greater prairie-chickens? The team found that the males’ body mass dropped by about 2 percent in the post-wind farm years, but birds closer to the turbines didn’t fare worse than those farther away. Scientists still don’t know if wind farms will suppress the number of prairie-chickens. But the results suggest it would be prudent to keep the turbines at least 8 kilometers away from leks.  Roberta Kwok | 14 May 2015

Source: Winder, V.L. et al. 2015. Responses of male Greater Prairie-Chickens to wind energy development. The Condor doi: 10.1650/CONDOR-14-98.1.

Image © Paul Sparks | Shutterstock