Scientists contend sage grouse breeding areas are suffering in the face of accelerating oil and gas exploration in Wyoming, Montana, Colorado, Utah and other Western states.
West Nile virus, drought and residential development also have taken a toll on the bird, which is being considered for the endangered species list.
Federal rules now say oil and gas companies cannot drill within quarter of a mile of sage grouse breeding areas. Last week, Idaho-based North American Grouse Partnership and the Theodore Roosevelt Conservation Partnership of Washington, D.C., filed a legal petition asking for the rule be extended to two miles.
"The birds aren't doing too well, and biologists have known for quite some time that a quarter-mile buffer was not effective," said Steve Belinda, a former Bureau of Land Management biologist now with the Theodore Roosevelt group. "The BLM has the authority to do better. Nobody has said they can't go beyond that if it's warranted."
An attorney for the groups said the government was obligated to consider the petition but not adopt it. A decision could take several months.
Unless drilling is slowed, Belinda said the chicken-sized grouse could end up on the endangered species list. That could shut down public hunting for the bird and prompt restrictions on residential development and agriculture.
One BLM field office, in Buffalo, Wyo., already is making preliminary moves to slow drilling. Officials there are considering more grouse protections on 200,000 acres to 400,000 acres in the Powder River Basin - a region along the Montana-Wyoming line where the birds live among tens of thousands of natural gas wells.
Under a pending plan, new development would be restricted temporarily in parts of the basin until more analysis is done on how to protect the bird. Other areas of the Powder River Basin would see drilling continue.
The conservationists' request on sage grouse comes as the U.S. Fish and Wildlife Service says it will decide by December whether to put the bird on the endangered species list. The agency declined to do so in 2005.
A judge in December ordered the agency to reevaluate that decision after determining it was tainted by political meddling from a Bush administration official who resigned in 2007.
