The U.S. Fish and Wildlife Service must reconsider the pygmy rabbit for listing under the Endangered Species Act, a federal judge in Idaho ruled last week.

Though there are no pygmy rabbits in Teton County, the decision could have grave implications for the future of energy development in Sublette County, south of Jackson Hole.

U.S. District Judge Edward Lodge found that Fish and Wildlife officials lacked sufficient scientific evidence to determine whether the animal warranted federal protection. The agency had ruled in a 2004 decision that the rabbit did not merit protection, but a host of environmental groups, including Western Watersheds Project and Biodiversity Conservation Alliance, took the decision to court.

Measuring between 9 and 12 inches long and weighing about 1 pound, pygmy rabbits are the smallest rabbit in North America.

The animals rely on large, dense stands of sagebrush for more than 90 percent of their diet, according to Martin Grenier, nongame mammal biologist with the Wyoming Game and Fish Department.

Sagebrush across the West has come under pressure from a host of factors recently, including the spread of invasive cheatgrass, housing development and a boom in energy development.

Environmental groups say this trend threatens all animals that depend on sagebrush for habitat and food.

“Pygmy rabbits are especially vulnerable to habitat fragmentation from the building of road networks because these animals are too shy to venture out from the cover of sagebrush to cross the road,” said Duane Short of Biodiversity Conservation Alliance. “For this reason, the huge level of oil and gas development targeting sagebrush basins in Wyoming is a major threat to the pygmy rabbit.”

Grenier agreed that energy development is probably the biggest threat to the animal in Wyoming, but he said those operations are reviewed by federal biologists for their impacts to the rabbit.

“Both industry and federal biologists are aware of the habitat requirements of the bunny and mitigate those impacts,” Grenier said. “It’s not fair to say it is happening without disregard.”

However, there are “data gaps” in the information scientists know about pygmy rabbits, including population trends across the state, Grenier said. Researchers are working to fill in those gaps.

Lodge’s ruling requires Fish and Wildlife to reconsider its initial finding in light of recent research.

Research in other states may find declining populations or distribution, Grenier said, but recent research completed by Game and Fish and the University of Wyoming has found a much greater distribution of rabbits across Wyoming.

If listed, the pint-sized rabbit could push the 100-foot-tall drilling rigs off portions of the Sublette County sagebrush where energy companies are pursuing two of the largest natural-gas fields in the country.