A golden eagle died last month when it collided with a wind turbine blade at a 47-turbine wind farm in Klickitat County.

The April 27 collision at the Goodnoe Hills Wind Project southeast of Goldendale was the first known eagle casualty caused by a Washington wind project.

"I don't know of any other eagle fatalities in the state in connection with colliding with a turbine blade," said Travis Nelson, the state's lead wildlife biologist on wind power issues. He called the incident "unfortunate."

Nelson said X-rays of the carcass conducted at a Washington State University wildlife laboratory in Pullman showed the 10-pound bird had a broken wing and two broken legs. The mature golden eagle has a six-foot wingspan.

The Washington Department of Fish and Wildlife is convening a group of stakeholders to review the incident and discuss how to prevent or minimize future eagle deaths, Nelson said.

"This is certainly not the outcome that anyone who was involved in planning and permitting this operation would have wanted, especially the project owner," he said. "We have convened a small review group internally to discuss how we can avoid this in the future."

The dead bird was found by the crew of URS Corp., a contractor for PacifiCorp, the Portland-based utility that owns the 94-megawatt Goodnoe Hills project. The wind farm began operating on June 30 of last year.

The golden eagle, dark brown with a golden sheen on its head and a large hooked bill, is common in Washington and throughout western North America. Though not listed as a threatened or endangered species, it is protected by the federal Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act. Both laws prohibit infliction of intentional harm on the raptor.

New guidelines

In April, state and federal wildlife officials, environmental groups and utilities completed a new set of guidelines intended to reduce the impact on birds, wildlife and other natural resources as new wind project proposals proliferate. About 20 groups and agencies took part.

The new guidelines call for extensive surveys of proposed wind farms before they are permitted, including monitoring of bird activity during different seasons and in multiple years. They also recommend leaving 2-mile-wide buffers around the nests of raptor species, including golden and bald eagles and ferruginous hawks.

Operators of wind projects are required to document bird kills and report them to state authorities. The death of the golden eagle was promptly reported to WDFW, as well as the U.S. Fish and Wildlife Service and PacifiCorp, Nelson said.

No public announcement of the eagle's death has been made.

"We're participating in a full review of the incident and working with WDFW and USFWS," said PacifiCorp spokeswoman Jan Mitchell. "We have a robust avian protection program and we proactively take steps to assure compliance with all regulations."

U.S. Fish and Wildlife Service spokeswoman Joan Jewett said her agency has an agreement with wind power operators who voluntarily report birds killed by power lines or wind turbines.

The agency issues carcass salvage permits to operators who agree to develop avian protection plans, report bird fatalities and agree to take steps to reduce them, Jewett said.

"If it's an eagle, the bird is sent to the National Eagle Repository north of Denver," she said. That federal repository provides feathers to members of recognized Indian tribes for ceremonial purposes.

Though the golden eagle death is the first reported in Washington, raptor deaths have been common at wind projects elsewhere. Between 570 and 835 raptors are killed annually in wind turbines at California's Altamont Pass Wind Power Resource Area, the world's largest.

Common in Gorge

Raptors are common in the eastern half of the Columbia River Gorge, where shrub steppe and grasslands offer prime habitat for prey such as ground squirrels and pocket gophers. The big birds typically soar at an elevation of 300 to 400 feet - about the same height as the rotating wind turbine blades.

Wind energy development gained momentum in the Northwest after both Washington and Oregon adopted requirements that utilities meet gradually increasing proportions of their energy loads with wind, solar and other renewable sources.

Klickitat County, which issued the permit for the Goodnoe Hills project, has been actively marketing itself as a site for wind development since 2005, when it adopted the nation's first energy overlay zone to speed the granting of wind power permits. Three wind projects currently operate in the county, five others are under construction and three more are proposed. SDS Lumber Co. is proposing to develop yet another wind project on its timberland in east Skamania County, near Underwood.

Klickitat's first wind project, the 200-megawatt Big Horn Wind Energy Project, began operating in 2007. Raptor mortality due to wind turbine collisions at the project has been far higher than predicted, according to a study by Shawn Smallwood, an independent wildlife ecologist who has also studied bird mortality at Altamont.

Smallwood estimated that the Big Horn project killed 243 raptors in its first year. The company's consultant had projected a toll of 33 raptors annually.