DECKER, Mont. - An awkward industrial dance is playing out on the sage flats of the West, a lopsided coupling of billion-dollar energy companies and a skittish ground bird prone to flee at first sight of a drilling rig.

If the bird, the greater sage grouse, lands on the endangered species list as some propose, that could put the brakes on the oil and gas activity surging through Wyoming, Utah, Colorado and Montana.

So during spring breeding, companies working some of the nation's richest gas fields let rigs go idle for months at a time rather than risk interrupting sage grouse mating rituals. Roads to oil and gas wells are rerouted to skirt the bird's territory. Power lines are buried to deny hunting perches to grouse-eating raptors. If those measures don't work, some companies are pledging tens of millions of dollars to recreate sage grouse habitat.

But as another breeding season ends this month and rigs again roll through the sage, a chorus of federal and university biologists and state officials says the companies' grouse conservation efforts are failing. With decades of drilling still planned, they say the industry must either redouble conservation or risk pushing sage grouse off the landscape.

Other forces also factor into the bird's decades-long decline - from cattle grazing and urban sprawl that pummeled once-vast sage brush expanses, to drought and West Nile virus outbreaks that hit the bird directly.

Grouse advocates single out oil and gas companies for criticism because they are pushing deeper into some of the bird's last strongholds: the Powder River Basin in Wyoming and Montana, the area surrounding the Roan Plateau in Colorado and the Green River Basin in Utah, Colorado and Wyoming.

Industry executives acknowledge their future in those areas is wound tightly around the grouse, a chicken-sized bird confronted by BP Amoco, Shell, Fidelity Exploration, EnCana Oil and Gas and dozens of other companies.

Yet the industry also has its own scientists, with their own opinions about sage grouse. And they say the effects of energy development are overstated.

"The reality with oil and gas is that we drill holes where the gas is and, unfortunately, that happens to be in sage grouse habitat," said Randy Teeuwen with Calgary-based EnCana, which has drilled 715 wells across western and central Wyoming and has hundreds more planned. "There is disturbance to sage grouse habitat. But we can manage that and stay ahead of that."

Some researchers and conservation groups contend increased drilling, spurred by calls to reduce foreign fuel imports, already is carving up some of the bird's best habitat. Figures obtained by The Associated Press show a 109 percent spike in federal drilling permits issued in Wyoming, Colorado, Utah and Montana under the Bush administration - from 2,355 in 2001 to 4,919 last year.

Another 110,000 wells are proposed or authorized in the four states, according to an analysis of more than two dozen federal drilling plans compiled by the Wilderness Society. That does not include wells drilled on state and private lands.

Meanwhile, emerging data indicates sage grouse populations are more prone to collapse than previously thought. U.S. Department of Interior regulators who oversee drilling on federal lands now say the industry must alter its practices to ensure the grouse's survival - a stark turnaround for an agency frequently accused of furthering the bird's demise.

What the grouse seem to need, said U.S. Fish and Wildlife Service biologist Pat Deibert, is space, and lots of it. She said research done by Matt Holloran at the University of Wyoming and Dave Naugle with the University of Montana indicates oil and gas wells may need to be spaced as sparsely as one per square mile for the bird to survive long-term.

Industry representatives counter with the unpublished research of consultant Renee Taylor, who contends grouse survive with as many as eight wells per square mile. Taylor said the notion that grouse and oil and gas operators cannot occupy the same swath of sage is "false."

Both sides agree grouse numbers are down significantly over the last 50 years. But that was long before the current energy boom got under way.

While the Fish and Wildlife Service lists oil and gas as the greatest threat to the bird in the Rocky Mountain region, Deibert acknowledged her agency does not know exactly why birds shy from development or its toll on the overall population. The most recent population figures span from 150,000 to as many as 500,000 grouse across their 11-state range.

In a bid to reconcile the conflicting views, Wyoming Gov. David Freudenthal will host a two-day sage grouse summit June 27-28, featuring academics, federal and state regulators, industry representatives and policy makers.

"There seems to be continuing arguments about who's data is right. I don't know," Freudenthal said in an interview. "But in the near term, we need to figure out what measures we can take to protect sage grouse and its habitat … Frankly, some (oil and gas) operators are doing great stuff and some aren't. The status quo may not be adequate."

The Fish and Wildlife Service in 2005 rejected a petition to list the grouse under the Endangered Species Act. A lawsuit seeking to reverse that order is pending before a federal judge in Idaho. Arguments in the case are set for July 9 in Boise, Idaho.

The plaintiffs, Western Watersheds Project, hope to gain some legal traction from the April resignation of a top Interior official, Julie McDonald, following an internal investigation amid charges she watered down science that supported listing the sage grouse and other species.

To avoid a listing in the near future, said Steve Torbit with the National Wildlife Federation, companies must scale back drilling plans immediately. "We've got to say in some places we shouldn't lease this for oil and gas," he said.

Company executives, such as Questar Corp. Vice President J. Paul Matheny, say they are willing to do more to protect the bird, but are not yet convinced it is needed. Methany said calls to rein in development are being driven by "an emotional response" to data yet to be substantiated.

Rather than operate under tighter rules, Matheny's company and its partners, Shell Exploration and Production and Ultra Resources, Inc., are offering up to $36 million to restore damaged sage grouse or mule deer habitat after the fact. Torbit and others warned that might not work.

"We're not really big on changing regulations because it's very difficult for industry to operate on a long-term time scale when the rules change," Matheny said. "The goal isn't to preserve every last deer or every last sage grouse; it's to maintain an ongoing stable population of those animals in a region."