By MATEUSZ PERKOWSKI
PORTLAND -- Environmentalists want a federal appeals court to halt grazing on a half-million acres of public land in Oregon because they say cattle are hazardous to the sage grouse.
The Oregon Natural Desert Association claims that grazing threatens "irreparable harm" to the bird's habitat in the Louse Canyon area of southeast Oregon overseen by the U.S. Bureau of Land Management.
The group recently asked the 9th U.S. Circuit Court of Appeals to issue an injunction against grazing in 2013 to prevent multiple threats to the sage grouse, such as a potential outbreak of West Nile virus.
Mosquitos breed in water troughs and puddles from hoof prints, encouraging the spread of the virus, which kills virtually all infected sage grouse, ONDA said.
"There's a clear and inescapable risk of exposure if these cows are released," said Mac Lacy, an attorney for the group, during March 6 oral arguments before the 9th Circuit in Portland.
An attorney for the BLM countered ONDA hasn't met the burden of proof that such an injunction is necessary.
The livestock troughs used in the region are deep and designed to keep water flowing to prevent mosquito reproduction, said John Smeltzer, attorney for the government.
The connection between hoof prints and West Nile virus is a "conjectural possibility" but there's no evidence to suggest it's a "significant game changer," Smeltzer said.
"There are already existing natural water sources. There are already mosquitos. The risk is already there," he said.
ONDA claims that grazing in Louse Canyon shouldn't be allowed in 2013 even without an injunction.
A federal judge previously found that the BLM's management plans for the area violated environmental law and vacated grazing permits for the area.
However, the judge allowed grazing to continue under previous permits while the agency conducts further studies on the effects of grazing on the sage grouse.
ONDA argued that grazing can't legally continue under the previous permits and must be suspended until BLM completes an analysis under the National Environmental Policy Act.
Sage grouse populations are particularly vulnerable in 2013 because of extensive rangeland fires last year, the group said.
"Relief from grazing until proper environmental review has occurred is more important than ever," said Lacy. "BLM has to do a NEPA review before allowing grazing on public land."
Like logging or another ground-disturbing activity on public land, grazing can't proceed unless it's specifically permitted by BLM -- if a new permit is canceled, the previous permit doesn't "spring to life," he said.
According to BLM, the judge canceled permits that called for new fences and water pipelines that promoted grazing in upland areas.
When those permits were set aside, grazing was resumed under the previously approved regime, said Smeltzer.
The agency was legally allowed to fall back on those prior permits, he said. "There was no basis for finding they were invalid."