Scientists are increasingly concerned about the number of birds killed by running into power lines and wind turbines, said Al Manville, a senior wildlife biologist with the U.S. Fish and Wildlife Service, but there are reports of success in preventing such incidents – at least in the case of the power lines.
More lines and turbines are planned in coming years, which could put several species of birds at risk, Manville said.
“We’ve got to address our carbon footprint and deal with climate change,” he said, “but we want to make sure, in the process, we don’t create new problems.”
If a project taking place in the Dakotas is successful, researchers say, it could hold implications throughout the Central Flyway, a major bird migration route that stretches from the Dakotas to Texas.
The study, underway near Coleharbor, N.D., by the U.S. Fish and Wildlife Service and the Western Area Power Administration, involves placing “diverters” on power lines where large numbers of birds fly between two local lakes. The coil-like diverters are often brightly colored and designed to spin or move in the wind. They give birds a visual cue to avoid the line.
To test the efficiency of the diverters, biologists collect and count the corpses of fallen birds beneath power lines. In 2006, before the diverters were in place, 429 dead birds were counted, said Misti Schriner, a biologist with the Western Area Power Administration.
After the devices were put in place, 344 dead birds were collected in 2007.
“I do believe there will be a decline,” Schriner said. Final results won’t be in for several months. Schriner noted that about 20% of the dead birds collected in this project were American coots, a common water bird. In central Nebraska, there are concerns about endangered whooping cranes and other species colliding with power lines near the Platte River, said Brad Mellema, director of the Iain Nicolson Audubon Center at the Rowe Sanctuary.
Only about 260 whooping cranes – enormous white birds with wingspans of up to 7 feet – exist in the Central Flyway, he said. Diverters have been put on lines for about a year, and Mellema expects to learn more about their effectiveness in coming months.
Researchers in San Joaquin County, Calif., are encouraged by a 60% reduction in bird fatalities after power lines were equipped with diverters, said Marcus Yee, whose findings were released in January.
In Northern California, a Government Accountability Office (GAO) study found more than 1,000 raptors were killed annually by wind-power facilities there. The area includes one of the nation’s largest concentrations of wind turbines in the Altamont Pass region.
In West Virginia, more than 2,000 bats were killed in a seven-month period in an area with 44 wind turbines, according to the GAO report. Bats are the primary predator of many insects, including some crop-damaging bugs, said Mike Duran, a vertebrate zoologist with the Nature Conservancy.
It was difficult for scientists to draw conclusions about wind power’s impact on wildlife because deaths of birds and other wildlife vary greatly from one region to another, the GAO report states.
Current research is important, because “birds play a key role in the ecosystem,” said Greg Butcher, director of bird conservation at the National Audubon Society.
“They serve as the canary in the coal mine,” he said. “We find that if humans are doing things in the environment that are bad for birds, it’s a good sign they’re doing things that are bad for humans as well.”
By Jeff Martin, USA TODAY
Martin reports for the Argus Leader in Sioux Falls, S.D.
23 June 2008
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