Sheep may save birds from turbines

Munch some grass. Save some hawks and eagles from gruesome deaths.

California, the nation's leader in wind energy, is looking at livestock grazing as a way to reduce the widespread killing of eagles, hawks and owls in the whirling blades of wind turbines.

In research with implications for the growing wind power industry, the California Energy Commission has approved $380,000 for scientists to test grazing as a tool to save raptors on Contra Costa grassland.

The test will begin using sheep to see whether the animals can eat down grass to the right height to drive away ground squirrels that lure raptors into fatal turbine collisions.

Scientists believe the squirrels, a raptor food source, will relocate away from turbines if the surroundings grass is either too low to hide the rodents from predators, or too high to obscure their ability to spot enemies overhead.

"The project could be a boon to making wind energy more environmentally acceptable," said Doug Bell, wildlife programs manager for the East Bay Regional Park District.

The district is overseeing the project that will be done in the next 18 months on its 1,339-acre Vasco Caves Regional Preserve between Brentwood and Livermore.

The district also is chipping in $75,000 for the work.

Last week, the park district hired a scientist to conduct the research.

The Vasco Caves preserve is teeming with ground squirrels, and it has 73 private wind turbines that were in place before the park district bought the land.

The preserve also is a few minutes soaring time from Alameda County's Altamont Pass wind farm area, focus of a complicated legal and political battle between energy companies and environmentalists over raptor deaths.

The park district has stayed out of the legal fray, but hopes it can break new ground in making turbines safer for birds.

Raptor deaths have been an impediment to the state relying more heavily on wind power, which supplied 1.5 percent of the state's electricity in 2004.

Wind power companies and raptors often like the same places.

Strong winds and abundant ground squirrels have given far eastern Contra Costa and Alameda counties one of the largest populations of eagles, hawks and falcons anywhere in the nation.

Hundreds have died each year in turbine collisions, according to the energy commission.

"Everything is tied around the vegetation levels," said Bell, also an assistant biology professor at Cal State Sacramento. "If it's hard to find ground squirrels, we think the raptors will go elsewhere."

Shepherds will rotate the animals into different spots to produce varying heights of grass.

Sheep landed the research job because they are easier than cattle to move about and produce precise heights of grass, Bell said.

However, if the tests prove effective, then cows, goats or even mechanical mowers might be used to get the desired grass levels, he said.

Researchers also will study raptor flight patterns to determine if certain terrain is suitable to locate new turbines with minimal risk to raptors.

Some ranchers have suggested the project is silly and has little chance for success.

But a state Energy Commission representative defended the project as a worthy pursuit of innovation to protect the environment.

"People had doubts about the catalytic converter," Adam Gottlieb of the commission said of the car pollution control pioneered in California. "The nature of scientific research is to explore the possibilities."

One environmentalist said the research is promising even if new turbine technology probably can do more to reduce raptor deaths.

"It could help, but it's not the entire savior for the raptors," said Jeff Miller, a spokesman for the Center for Biological Diversity.