DENVER – The federal government this week declared more than 400,000 acres in southwestern Colorado and eastern Utah off-limits to energy exploration or any other kind of development to protect the Gunnison sage grouse, a precursor to a much larger fight over another species of the bird that ranges across 11 Western states.

The Bureau of Land Management directive released Monday formalizes protections the government already had implemented to preserve the Gunnison grouse. A decision about whether to list it as an endangered species is due in November.

BLM spokesman Steven Hall said the protected land falls in 800,000 acres that have been identified as the bird’s general range.

The Gunnison sage grouse lives only in a small sliver of Colorado and Utah, and the estimated 4,500 animals remaining are about one-tenth of its original population. Because it is so depleted, Hall said, its habitat has to be protected aggressively.

A similar species, the greater sage grouse, has more of an impact on the West. The greater grouse, while still below its peak population, is healthier and doesn’t require as stringent on-the-ground development limitations, Hall said.

But its range is far bigger, covering 160 million acres in 11 Western states. That land includes many of the areas under gas and oil development as part of the ongoing energy boom.

“We don’t see as many conflicts between energy production and habitat protection with the Gunnison sage grouse as we do with the greater sage grouse,” Hall said.

A decision about whether to list the greater sage grouse as endangered is due next year. Western states fear the bird will receive federal protection, inhibiting development and ranching in huge parts of their territory.

The BLM’s protections for the Gunnison sage grouse already are causing economic damage, said Kathleen Sgamma of the Western Energy Alliance. The steps the federal government will take if the greater sage grouse is listed will be more devastating.

“It’s a microcosm of what’s happening across the West,” she said of the latest BLM policy.

Last week, the Western Governors Association passed a resolution urging the federal government to defer to states on greater sage grouse conservation.

On Tuesday, Utah legislators set aside $2 million to lobby the federal government to postpone its expected September 2015 listing of the greater grouse.