The Altamont Pass windmills are killing more hunting birds than ever after two years of trying to cut the deaths by half.
From October 2005 to October 2007, the deaths among four raptors studied — golden eagles, red-tailed hawks, American kestrels and burrowing owls — increased 27 percent overall, according to a review committee following the project to protect the birds.
Only the golden eagles as a group showed fewer deaths, a decline of 21 percent.
The panel estimated a total of 2,236 raptors were killed annually during the study period. The two-year increase was measured against a baseline study of the kills from 1998 to 2003.
The problem is that the Altamont Pass is a rich hunting area for the birds, but they fly into the spinning blades of the wind-power generators profusely spread across the hills.
The new data were revealed in a summary of a full study that is expected later this week.
Late last year, the review committee intimated measures taken by wind-power companies had not done enough to achieve a 50 percent reduction in raptor deaths by November 2009.
That goal was part of a January 2007 settlement of a lawsuit filed by the Golden Gate Audubon Society, Californians for Renewable Energy and four other Audubon chapters challenging Alameda County's decision to renew permits for Altamont Pass wind turbines.
The committee's concerns caused some windmill operators to agree to shut down the windmills longer than a previous two-month winter period. The committee also put nearly 100 turbines into the two highest-risk category of windmills that contribute to bird kills.
The committee said the turbines need to be removed or relocated.
"Obviously, we're deeply distressed" by the latest numbers, said Elizabeth Murdock, executive director of the Golden Gate Audubon Society.
Murdock noted that the numbers might not fully reflect how well the prevention measures were working. Two key elements, the winter shutdown and removal of the highest-risk windmills, did not occur until at least early 2007. Also, she said, the bird population may have increased.
Nevertheless, Murdock said, the kills have not declined and that is of grave concern.
A spokesman for one windmill company said he would withhold comment until the full report comes out.
"We want to be part of the solution," said Steven Stengel, a spokesman with FPL Energy. "It is our goal and objective to reduce the number of bird collisions in the area. We will continue to work with (the other parties) on this issue."
Alameda County also intends to find solutions, said Chris Gray, chief of staff for Supervisor Scott Haggerty whose district includes the windmill area.
He said "re-powering" may be one possible solution, where larger, more efficient windmills replace a handful of the smaller turbines. Some data show these windmills kill fewer birds because of their larger size and slower movement.
Reach Chris Metinko at 510-763-5418 or email@example.com.