BOISE, Idaho - Livestock and farming groups in four Western states are challenging a ruling by a federal judge in Idaho who ordered the U.S. Fish and Wildlife Service to reconsider whether sage grouse deserve federal protections.

The government decided against adding the bird to the endangered species list in 2005, a move that allowed ranchers and the oil and gas industry to escape stiff regulations.

An environmental group sued in federal court last year to force the Fish and Wildlife Service to revisit its decision on the sage grouse, a chicken-sized bird with long pointed tail feathers. Scientists say the popular game bird is on the decline and the population has plummeted in the face of accelerating oil and gas exploration in the West.

West Nile virus, drought and residential development have also taken a toll on the bird.

In December, U.S. District Judge B. Lynn Winmill ruled in favor of the Western Watersheds Project, saying the federal agency had ignored expert advice and failed to use "best science" in its sage grouse decision.

Last week, attorneys with Sacramento, Calif.-based Pacific Legal Foundation appealed that decision in the 9th U.S. Circuit Court of Appeals on behalf of ranching, livestock and farming groups in Idaho, Oregon, Wyoming and Nevada. The appeal seeks to overturn the decision on a minor detail, a 60-day notice that attorneys for the Western Watersheds Project failed to file in federal court in advance of their formal lawsuit.

"I frankly don't think it's any big deal, I think they're grabbing at straws," said Laird Lucas, executive director of Advocates for the West, a public interest law firm in Boise that is representing the environmental group.

The Fish and Wildlife Service initially appealed the decision, but then backed off, Lucas said.

"I think that the fact that the Fish and Wildlife Service has dropped their appeal speaks volumes," he said. "They're not contesting it."

Last year, the states of Idaho, Wyoming and Colorado joined sides with the service, arguing they spent significant time and money creating their own conservation plans to protect sage grouse, and that the plans were working.

Ranching and farming groups also joined the lawsuit, saying the service followed all the rules required by the Endangered Species Act in making its determination.

Foundation attorney Brandon Middleton said the case should have never been argued in federal court last year because the Western Watersheds Project didn't file the 60-day notice, a flaw the judge should have recognized earlier.

"It is a technical requirement, but it's an important one," Middleton said.