October 29, 2007
Wind Farms Generate Bird Worries
The rapid expansion of wind energy farms in the Columbia River Gorge's shrub steppes could put hawks, eagles and other raptors on a collision course with fields of giant turbines and their 150-foot blades.
By year's end, more than 1,500 turbines will be churning out electricity in the gorge, a windy corridor at the forefront of a nationwide effort to produce cleaner energy. Until now, most of the projects have gone up in wheat fields -- cultivated land that long ago drove away the rodents that raptors hunt.
The numbers sound small: Nationwide, collisions kill about 2.3 birds of all varieties per turbine per year, studies show. In the Northwest, it's about 1.9 birds per turbine. That could mean more than 3,000 bird deaths a year in the gorge.
But birders say those numbers are meaningless because the totals make no distinction between abundant and rare species. Golden eagles and ferruginous hawks -- a threatened species in Washington -- already are few in number, said Michael Denny of the Blue Mountain Audubon Society, and even a few fatalities could prove devastating.
"We'll have certain species in sharp local decline," Denny said. "If you lose breeding populations like the ferruginous hawk, you're not going to see them recover."
Raptors generally fly 300 to 400 feet above the ground -- about the height of most wind turbines. Hawks and eagles ride the thermals off the high windy ridges above the Columbia River as they search for ground squirrels and pocket gophers. Some are migratory and others are resident birds.
Raptors are known for their keen eyesight and might learn to negotiate the turbines and their spinning blades, studies suggest. But hunting and migrating instincts are so ingrained and so intense that the birds might not see the obstacles until it's too late, biologists say.
The shrub steppes and grasslands that cover large swaths along the river east of the Cascades are classic raptor habitat, said David Anderson, a district biologist with the Washington Department of Fish and Wildlife. "We have concerns we're losing that habitat."
But even the cultivated areas with wind farms have bird experts worried. In Oregon's Sherman County, several hundred turbines stretch through wheat fields outside the small town of Wasco, creating one of the highest concentrations of wind farms in the gorge.
"They're going up so fast, we're worried about the cumulative effects," said Keith Kohl, a wildlife biologist for the Oregon Department of Fish and Wildlife's mid-Columbia district.
Energy companies conduct wildlife studies before pegging a specific site for development. They submit their findings to state or county authorities, who decide whether projects will go forward.
In some cases, regulators have required developers to shift turbine locations, establish buffer zones or set aside acreage exclusively for wildlife.
Often, developers must patrol their wind farms and record bird kills.
"We pride ourselves on building projects that adhere to the requirements," said Darin Huseby, Northwest regional director for developer enXco Inc., a California-based company with several projects in Klickitat County. "We want to be a net benefit to the environment."
Bird experts don't know how many raptors fly above the steppes, but it's a well-documented and well-traveled migratory route. It's also known breeding territory for golden eagles. At least one pair nest within two miles of a wind project under construction in south-central Klickitat County, and birders fear the worst.
"They're going to get whacked," said Denny, the Blue Mountain Audubon Society representative, who tried to stop the 97-turbine project, called Windy Point. "They'll fly right into those turbines."
A report by the federal Bonneville Power Administration suggests that annual bird fatalities in the gorge would be similar to the Northwest rate. The BPA reviews wind projects before hooking them into its transmission network. The report concluded that "cumulative mortalities in the Pacific Northwest region are relatively insignificant" compared with total bird populations in the area.
So far, developers have found three dead ferruginous hawks at operating wind farms, two in Washington and one in Oregon.
Portland-based PPM Energy recorded one of those kills at Big Horn, its 133-turbine project in Klickitat County. To compensate, the company agreed to help pay for a study that will tag several ferruginous hawks with radio transmitters and chart their movements.
During the permit process, PPM also agreed to exceed requirements for setbacks from a canyon frequented by raptors, and it bought 455 acres for a turbine-free conservation area, said Jan Johnson, a PPM Energy spokeswoman. "We know it's a community that loves its birds, and we take that seriously."
Washington biologists already have placed radio collars on golden eagles, red-tailed hawks and Swainson's hawks to track the birds in Klickitat County.
Preliminary mapping of wind turbines and tagged raptors has yielded "compelling results," said Bill Weiler, a habitat biologist with the Washington Department of Fish and Wildlife. "It shows high concentrations of raptors in areas where turbines are proposed."
Other birds also could be in danger. Some of the turbines under construction at Goodnoe Hills in Klickitat County skirt an oak grove. One will rise less than 100 feet from the tree line, despite biologists' request for a 300-foot setback.
Lewis's woodpeckers, ash-throated flycatchers and owls are among the birds that perch and nest in the oaks, Weiler said. "Oak woodlands are magnets for birds. It's habitat that should be buffered."
Huseby of enXco, a partner in developing Goodnoe Hills, said the close-in turbine was a mistake. To compensate, he said, the company has agreed to pay for further bird studies and to fence the base of the turbine so animals that attract birds stay away.
The company has acted responsibly, Huseby said, but the public must be the final arbiter.
"The reality of our economy, our way of life is that we need to build certain facilities to provide electricity," and they will have certain effects on the environment, he said. "It's a societal question: What degree of (bird) mortality are they willing to accept?"