BEND, Ore. - The Bureau of Land Management is using some stimulus money to study the effect of wind farms on a dwindling sage grouse population in Central Oregon.

BLM spokesman Michael Campbell said the agency hopes to lessen or eliminate any impact.

The agency would hire people to tag sage grouse in areas where wind farms are proposed and track the birds' movements to figure out where turbines could be located. Contracts have not yet been awarded.

The BLM has no wind farms on its Oregon land but has received three applications. There are turbines on private land.

Sage grouse numbers in Oregon last year were at their lowest in a decade but may be rebounding in some areas.

"2008 was not a good year for sage grouse, there's no question," said Christian Hagen, the sage grouse coordinator with the Oregon Department of Fish and Wildlife.

It is difficult to gauge the population from spring counts. The sage grouse population in 2008 fell to an estimated 20,000 to 25,000 birds in 2008, less than half the estimate from 2005.

There was talk of including the sage grouse on the federal endangered species list. The U.S. Fish and Wildlife Service is expected to visit the question again, Hagen said.

Hagen said reasons for the decline could be drought, invasive plants and encroaching junipers, West Nile virus and human activities.

The chicken-size bird, with its long, spiked tail feathers, has been called the spotted owl of the desert because its listing could drastically change what people can do with the land.

What happens to sage grouse reflects problems with other species in the high desert, said Eric Hess with the Seattle-based nonprofit Sightline Institute, which recently released a report about sage grouse numbers. And over time, the sage grouse has been on the decline.

"The highs are getting a little lower, and the lows are getting a little lower," Hess said. "Human activity is playing a role in disrupting the ecosystems out there, and we need to look at different conservation measures."

"It's one of those classic situations of death by a thousand cuts," said Brian Fenty of the Bend-based Oregon Natural Desert Association.

State biologists have recommended siting wind turbines at least three miles from sage grouse breeding habitat, but in March, Crook County approved a proposed $220 million wind farm closer to the birds.

Crook County Judge Mike McCabe said the birds don't fly high enough to hit the turbine propellers.

The Crook County project is also near a small population of the birds on the edges of their range, he said, so it shouldn't have much of an impact.

Weather also can be a factor, said Hagen, with the Department of Fish and Wildlife. A drought in 2007 and 2008 reduced the vegetation that protects nests and the grasses and wildflowers chicks eat.

Biologists found birds that had died from West Nile virus in 2006 and 2007, he said, but don't know how widespread it is.

So far it looks like numbers in the center of the sage grouse's Oregon range - Malheur, Harney and Lake counties - are up a little, he said.

Numbers from mating areas on the fringe of the birds' range in Deschutes and Crook counties, however, don't look as promising, he said.

For unknown reasons, the fringe areas tend to lag behind the core areas, Hagen said, adding that he anticipates the numbers will turn around locally in the next year or two.

"If things were to continue in a downward trend for a couple of years, we would be concerned," he said.

At a glance

In 2008, the sage grouse population fell to an estimated 20,000 to 25,000 birds, less than half the estimate from 2005.

In 2006 and 2007, biologists found birds that had died from West Nile virus.

A drought in 2007 and 2008 reduced the vegetation that protects nests and the grasses and wildflowers chicks eat.