BILLINGS (AP) — A government report with significant implications for the U.S. energy industry says the breeding grounds of a struggling bird species need a 3-mile or larger buffer from oil and gas drilling, wind farms and solar projects.

The study comes as the Obama administration weighs new protections for the greater sage grouse. The ground-dwelling bird ranges across 11 western states.

A 3-mile buffer is a much larger protective area than the no-occupancy zones where drilling and other activity is prohibited under some state and federal land management plans.

Those plans also contain more nuanced provisions that backers say will protect sage grouse, such as seasonal restrictions on drilling and limits on the number of oil and gas wells within key sage grouse habitat.

But some wildlife advocates say too much development is being allowed under those plans, undermining efforts to help grouse.

Such opposition could be bolstered by Friday’s report from the U.S. Geological Survey.

Greater sage grouse populations dropped sharply in recent decades due to disease, pressure from the energy industry, wildfires and other factors.

The new report comes as state and federal officials scramble to come up with conservation measures to protect the grouse ahead of a court-ordered September 2015 decision on protections.

The USGS did not recommend specific management recommendations. But survey scientists said it should help the Interior Department as it crafts a conservation strategy for the birds.

A related bird, the Gunnison sage grouse of Utah and Colorado, received federal protection as a threatened species on Nov. 12. An adviser for Colorado Gov. John Hickenlooper said Friday that the state plans to challenge the decision in court.

The USGS report on the more-common greater sage grouse represents a compilation of scientific studies aimed at seeing what it takes to protect the bird.

It was requested by the U.S. Department of Interior’s Bureau of Land Management, the federal agency that oversees millions of acres of sage grouse habitat and also regulates the energy industry across much of the West.

It said a minimum buffer extending to a 3.1-mile radius around sage grouse breeding sites would provide considerable protections for the bird. That radius would equal a circle around the leks covering 30 square miles.

The report suggests a maximum buffer of 5 miles.

By comparison, Montana and Wyoming have adopted management plans for the bird that call for a no-surface occupancy zone of six-tenths of a mile around breeding sites, or leks, in key sage grouse habitat. That’s an area of slightly more than one square mile.

The state plans also limit human activity within a larger area around breeding and nesting seasons. And they take into account cumulative impacts, such as a restriction in Wyoming that limits oil companies to one well pad per square mile in key habitat. That keeps sage grouse habitat intact, Wyoming Petroleum Association Vice President Esther Wagner said.

“That reduces (habitat) fragmentation, which is what it all comes down to,” Wagner said. “It’s working here.”

But Steve Holmer, a senior policy adviser for the American Bird Conservancy, said larger no occupancy areas around leks are needed if sage grouse populations are to survive.

“There really need to be a hard and fast rule about no occupancy,” he said. “We have been asking for 4 miles, and if this study provides strong evidence for 3 miles, we’ll have to consider that.”

Carol Schuler, USGS senior science adviser, said that land managers also need to take into consideration local conditions across the grouse’s sprawling, 257,000-square-mile habitat. She said the buffer recommendation offered Friday was meant to give a reference point as more localized decisions are made.

“It’s really up to the management agencies on how they use this information,” Schuler said.