Greater Prairie-Chicken Nesting Not Affected Much by Wind Turbines

Greater prairie-chickens at the Switzer Ranch in Loup County, Nebraska. (Photo courtesy Don Henise via Flickr Creative Commons)
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October 27, 2017 - 6:45am

Some of the best places to generate wind energy in Nebraska are also home to many species of grassland birds. New research offers a better understanding of how one prairie bird responds to wind turbines.

Each spring, greater prairie-chickens gather in open grasslands to perform an elaborate mating dance. The male brown-and-beige-striped birds stomp their feet, fan their tail feathers, and inflate orange air sacs in their necks to display dominance, all while making a series of sounds known as “booming calls.”

“Prairie chickens are one of the iconic species of the prairies, of the Great Plains,” said Mary Bomberger Brown, a research assistant professor at the University of Nebraska-Lincoln who studies birds. The places where these mating displays occur are called “leks.”

“A prairie chicken lek, in the springtime, early in the morning when the males are dancing and displaying and doing their boom vocalizations, it's a treat,” Bomberger Brown said.

Male birds dance to attract females, and the pair will usually pick a nesting site within two miles of the lek. Greater prairie-chickens aren’t a threatened or endangered species—in fact, you can hunt them in Nebraska. But the Nebraska Game and Parks Commission still wants to protect them, and their nesting grounds.

“Nebraska and parts of South Dakota are probably the last stronghold of the greater prairie-chicken in the country. Their range has really contracted. In other parts of the country their numbers are greatly diminished. So maintaining populations here is important for the survival of the species,” said Jeff Lusk, upland game program manager.

In Nebraska, greater prairie-chickens are mostly found in the Sandhills, which has also become a popular location choice for wind developments in recent years. Lusk said his agency wanted to know how wind farms could affect these birds, especially since previous research had shown similar bird species tended to avoid areas around vertical structures.

“So we were worried that not only the wind towers, which is a large vertical structure, but the infrastructure that has to go in around them, like the transmission lines, would create disruptions,” Lusk said. The agency funded a UNL study to look into it.

Mary Bomberger Brown was one of the lead researchers. She said avoiding tall structures is a survival strategy for grassland birds who evolved with no trees or other large vertical structures on the landscape. “If you're a ground-nesting grassland bird, a big, tall structure could be a tree, and it's something where predators perch,” Bomberger Brown said. The low-frequency noise turbines make can present another challenge.

“In the case of prairie-chickens, it matches the frequency of the chorus that male prairie-chickens make to attract females and to attract other males to the lek," Bomberger Brown said.

Wind development in the Sandhills is already contentious. Proponents cite the benefits of renewable energy and local tax revenues, while opponents worry the wind farms and associated infrastructure will damage the grassland ecosystem and spoil the open horizons.

The Sandhills region has some of the best wind power potential in the state, but it’s also one of the largest intact grasslands in the country. Larkin Powell, another lead researcher on the project, said that makes it a priority area for conservation. Their study looked at a range of potential effects the turbines could have on greater prairie-chicken nesting.

“Most people think of them as potentially negative,” Powell said. “But one possibility is that [because] raptors avoid turbines in other places, it could actually be the safest place to be a prairie-chicken is next to one of these turbines.”

The team studied an existing wind farm near Ainsworth, gathering data on 91 nests at various distances from the turbines. After two years, Powell said they found that the turbines didn’t seem to bother the birds much.

“It doesn't affect where they nest, it doesn't affect where they move, it doesn't affect where they take their broods during the breeding season,” he said. But they did find that the birds tend to avoid nesting near roads, which is important because roads are needed to service every individual turbine. Researchers also found somewhat fewer predators near turbines.

Special thanks to E.J. Raynor of the University of Nebraska-Lincoln for providing the booming calls recording of the greater prairie-chicken.

Raynor, Powell and Larkin also worked on a separate study which found that the low-frequency noise from wind turbines did not appear to affect the presence or singing behavior of breeding birds in the Sandhills. Find the study here.

The takeaway, Bomberger Brown said, is that wind developers should keep local data in mind when planning to build.

“Anywhere in the state or anywhere you’d want to put a wind farm, there are complexities. Every landscape and every small section of the landscapes are very different, and so the specifics of the siting of it need to be thought of as more complex questions,” Bomberger Brown said.

The state has guidelines to help wind developers avoid and minimize harm to different habitats and species. Those include recommendations to avoid building a turbine close to a known lek site, and on collecting bird survey data before and after construction.

Jeff Lusk of NGPC explains the guidelines are voluntary: “The companies come to us not because they're required to, but because if they get a letter from us saying we don't think there's going to be an environmental impact that provides cover for them in case something goes wrong.”

Game and Parks says most developers work within the established guidelines, and this new research may help update those guidelines with new information. Bomberger Brown said that’s valuable, “If we can find better ways of allowing the prairie-chickens and the wind turbines to occupy the same space, that's a good thing.”

By helping one species of grassland bird, she said, we’re likely helping other at-risk prairie birds too.



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