Straight through the golden nest: Biologists fear power line will disrupt eagles
FARGO — Biologists are concerned that a proposed power transmission line that would skirt the southern Killdeer Mountains in western North Dakota could disrupt nesting habitat for protected golden eagles.
A research biologist said the eagles around the Killdeer Mountains are of special concern because they exhibit rare paired hunting and group hunting behavior, never before documented in golden eagles.
Marguerite Coyle, an assistant biology professor at the University of Jamestown who has studied the golden eagles since 2002, said placement and construction of the power line could disturb nesting sites. She’s also concerned eagles could be electrocuted or be killed by striking the lines in flight.
“It’s a big concern,” Coyle said. “You’re putting power lines through one of the highest-density areas of golden eagles in North Dakota.”
Coyle has submitted testimony about her concerns about habitat disruption in federal and state reviews of the power line Basin Electric Power Cooperative is proposing. The line would extend almost 200 miles from its Antelope Valley Station northwest of Beulah to a substation near Neset in western North Dakota.
Coyle and biologists for the U.S. Fish and Wildlife Service, which also has provided comments about the proposal, are concerned that the project’s disruptions would be especially harmful to breeding eagles and juvenile eagles.
The transmission project should take an alternative route to avoid what Coyle calls “vital nesting habitat” for golden eagles, she wrote to the U.S. Department of Agriculture Rural Utilities Service, which is conducting the federal environmental and cultural resources review of the project.
Basin Electric said the power line is needed to meet a dramatic increase in power demand stemming from the oil boom in western North Dakota.
“Basin Electric’s current route goes through the heart of one of the most important” golden eagle habitat sites in the state, Coyle said. The area provides important nesting and hunting terrain, and also is a major migration route for eagles in North Dakota, she said.
Federal laws protecting bald eagles and golden eagles require that eagle nests not be disturbed unless a permit has been obtained, which requires an eagle conservation plan.
A draft review by the Rural Utilities Service found about 97 raptor nests within a one-mile corridor of the proposed transmission route but did not identify any active golden eagle nests, said Jeffrey Towner, field supervisor for the U.S. Fish and Wildlife Service’s North Dakota Field Office in Bismarck.
But even eagle nests that appear inactive or unoccupied cannot be disturbed and should be protected, Towner said. Eagles sometimes use multiple nests and rotate among them, he said.
Federal wildlife officials are asking the project reviewers to make “doubly sure” there are no eagle nests that could be disturbed by the transmission line, he said.
“We believe they should take our recommendation into account,” Towner said. “In my view they would be well-advised to make absolutely sure that anything they authorize or provide funding for would not result in unauthorized taking of an eagle.”
The route Basin Electric proposes for the transmission line in the area of the Killdeer Mountains in Dunn County has strong support from landowners, said Curt Pearson, a Basin spokesman.
Because of strong landowner acceptance, and problems encountered by development farther south of the Killdeer Mountains, Basin Electric is not proposing any alternate routes in the area, he said.
“Basin is going to be working with the federal agencies to mitigate any impacts that are identified,” Pearson said.
Although advocating for protection of eagles and nesting sites, federal wildlife officials are not asking that the transmission route be altered. Standard procedures call for taking steps to minimize bird collisions or electrocutions from power lines, Towner said.
The cooperative hunting behavior of the golden eagles in North Dakota first was observed and documented in 2003, Coyle said.
Researchers observed 11 groups of adult eagles, with two or more hunting together in nine areas known to be occupied by the eagles. Since then, cooperative hunting among golden eagles has been documented in multiple years and sites, suggesting to Coyle that the practice is not a “fluke.”
All of the instances of group hunting involved nesting eagles, with many confirmed to be rearing young, Coyle said.
Because of widespread oil and gas development, golden eagles and other species are experiencing habitat fragmentation and human disturbances, Towner said.
“We believe they’re under unprecedented pressure, and we’re concerned,” he said. “I think wildlife in general is under unprecedented pressure.”
Eagles have been protected by federal law since 1940.