That gives weight to arguments by preservationists who succeeded last year in persuading a federal judge to order the U.S. Fish and Wildlife Service to review its decision not to list greater sage grouse in 11 Western states.

U.S. District Judge B. Lynn Winmill in Boise, Idaho, said the service's decision was wrongly influenced by political pressure from an Interior Department assistant secretary, Julie MacDonald. She resigned after Winmill wrote that she tampered with scientific conclusions and intimidated staff members.

Should the wildlife service's review result in a finding next year that federal protection is warranted for sage grouse, plans by renewable energy companies to build wind power turbines and transmission lines across the West could change drastically. Some of the best locations for wind power turbines and transmission lines overlap sagebrush habitat that grouse rely on for survival.

Mining, oil and gas exploration and livestock grazing on public lands would also be impacted should sage grouse be listed.

"The reality is that Nevada already has overlay of the transmission areas and habitat of the birds," Bob Williams, the service's field supervisor for Nevada, said this month.

"It would be no different than the desert tortoise being listed," Williams said.

As in the case of the tortoise, he said, federal biologists would have to consult with public land administrators and developers of private projects to ensure enough grouse remain and habitat is protected for the bird's continued existence.

The ongoing review and data collection by wildlife officials in states where sage grouse live was spurred by the Western Watersheds Project. The conservation group in Idaho sued the wildlife service over its decision not to list greater sage grouse in 2005.

Laird Lucas, executive director of Advocates for the West, a public interest law firm representing the watersheds project, said the government's lead scientists must prepare a comprehensive update on the status of the sage grouse by November with a deadline of May 2009 to decide whether listing the sage grouse as threatened or endangered is warranted.

If warranted, a year of public hearings would follow with a final listing rule in May 2010.

The project's biodiversity director, Katie Fite, said sage grouse population estimates by wildlife agencies might be inflated and are guesswork at best. They're based on surveys of "leks," or "drumming grounds" where males strut with fanned tails and puffed chests to attract females during mating season.

Fite, a biologist, said declining numbers of sage grouse are linked to wildfires that have destroyed dozens of leks in Northern Nevada and Idaho.

In Nevada alone, 3 million acres of sage grouse habitat has burned since 1999.

Sagebrush, which accounts for 99 percent of the grouse's winter diet, takes many years to recover in burned areas. Instead, invasive weeds such as cheatgrass, take over and provide fuel for more fires. Livestock grazing, too, affects sage grouse habitat.

Fite said sage grouse hens need sagebrush surrounded by tall grass to cover their nests. Chicks also are dependent on eating insects from wildflowers and leafy forbs.

Disruption of those habitats from building large wind farms, transmission lines and exploring for natural gas and oil would accelerate the grouse's downward spiral, Fite said.

"What happened is that sage grouse numbers are going down, down, down," Fite said. "They're disappearing or diminishing or will disappear over much of their range."

She said oil and gas exploration in Wyoming, Utah, Colorado and Montana has "ripped apart habitat that was intact a decade ago."

In Nevada, the two-year decline in grouse numbers is attributable not only to wildfires but irregular precipitation patterns, said Shawn Espinosa, upland game specialist for the Nevada Department of Wildlife.

"We were seeing increases in the population up until 2005 to 2006. Then, over the last couple years, the population has seen decreases. In some cases, the decreases have been pretty sharp," he said.

"I think overall, the biggest reason is we've had a couple poor springs in a row where we haven't had the right precipitation pattern," he said.

Normally out of a brood, about two chicks per hen are added to the population after evading predators and enduring dry conditions.

Last year, however, Espinosa said the ratio fell to 0.58 chicks per hen, the lowest recorded since the early 1980s.

Fite said she understands efforts to wean the nation from dependence on foreign oil, but she prefers small renewable energy projects close to communities over big centralized facilities that require extensive transmission systems.

She fears the sage grouse's fate will fall into the hands of human encroachment from energy development.

"If we don't have run-amok oil and gas development, we have wind farms being built in sage grouse habitat," she said.

"What's going on right now is a scramble to get approval for projects and right-of-ways before sage grouse do get listed because these power lines are not compatible with sage grouse," Fite said.

Charles Benjamin, director of the Nevada office of Western Resource Advocates and president of a coalition, Nevadans for Clean, Affordable, Reliable Energy, believes sage grouse and clean energy projects can coexist with proper planning.

"We're confident in the environmental community that this can be done right," he said Friday.

Benjamin noted that the Western Governors Association has an initiative to identify renewable energy zones that are best for wind, solar, geothermal and biomass projects as well as identify endangered species habitats and the best sites for transmission systems.

"We call them smart transmission," he said.

Though he said he's not an expert on endangered species laws, Benjamin said there's "no question" that listing sage grouse would restrict activities in habitat areas "or may eliminate them altogether."

"And that would affect wind turbines or transmission lines that are bringing energy from a more distant project," Benjamin said.

"We think there is enough open land out there, which is not habitat for threatened and endangered species."

Contact reporter Keith Rogers at krogers @reviewjournal.com or 702-383-0308.