Seven of nine grassland bird species were displaced from breeding habitat on mixed-grass prairies after wind turbines were built at sites in North Dakota and South Dakota, a study found.
The U.S. Geological Survey report, recently published in the journal Conservation Biology, found that susceptible bird species avoided turbine locations for years after construction, including species in “serious decline.”
Bird species that avoided wind farms included the western meadowlark, the North Dakota state bird, which has been in decline in the state. The meadowlark moved 300 to 1,000 meters from the turbines, or more than 984 to 3,280 feet.
Other species included the bobolink, which also moved 300 to 1,000 meters, and grasshopper sparrow, which moved 300 meters, or 984 feet.
The period in the study, the decade from 2003 to 2012, coincided with the emergence of the wind industry in North Dakota, which provided 17 percent of the electricity generated in the state last year, enough to power 582,000 homes.
Major effects from birds avoiding wind turbines probably won’t be apparent in local areas, but scientists are concerned about the cumulative effect from many disturbances, including native prairie plowed under for crops and industrial development, Shaffer said.
“We actually got in on the ground floor of the wind industry moving into North Dakota,” said Jill Shaffer, an ecologist at the USGS and one of the study’s authors.
NextEra Energy, the leading wind developer in North Dakota, helped fund the study, Shaffer said. Comment from NextEra was not immediately available Monday.
North Dakota’s installed wind capacity has grown rapidly in recent years to rank 11th in the U.S. with 1,886 megawatts, driven by 1,086 turbines, according to figures from the American Wind Energy Association.
Researchers gathered data from three wind farms in grasslands in Hyde County hear Highmore, S.D., and in Oliver County in North Dakota. Scientists monitored changes in the density of breeding bird pairs overall and in relation to distance from wind turbines.
One bird species, the killdeer, nests in gravel, which wind developers use to surround wind turbine pads. In the first year after construction, killdeer established nests near the turbines, said Shaffer.
But in subsequent years, because of disturbances at the turbine sites, the killdeer stayed away, she said.
“They found out from the first year that there is a lot of traffic,” including workers maintaining the site, Shaffer said.
The grasshopper sparrow is particularly sensitive to habitat disruption. “It doesn’t tolerate much disturbance,” Shaffer said. Meadowlarks, by comparison, are more tolerant, and are known to perch, for example, on farm fence posts.
“The Great Plains supports some of the last remaining native temperate grasslands in North America,” she said. With proper management, she added, wildlife habitats can be maintained for the benefit of both animals and people.
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