Courtesy of Courtney Conway
Courtesy of Jill Wussow
MOSCOW, Idaho — Spring cattle grazing doesn’t appear to adversely affect sage grouse nesting success on public lands, according to initial findings of an ongoing, exhaustive research project involving ranchers throughout Idaho.
The planned decade-long study has concluded its fourth year. It is led by University of Idaho professor Courtney Conway, who also serves as director of the U.S. Geological Survey Idaho Cooperative Fish and Wildlife Research Unit — a partnership of UI, the U.S. Department of Interior and the Idaho Department of Fish and Game.
Conway described the study as “the most rigorous and thorough of its kind in an unprecedented way” and said it should provide a more scientific basis for future Bureau of Land Management grazing policies in sage grouse habitat.
Eight ranchers using public lands inhabited by sage grouse south of Bruneau, south of Twin Falls, south of Burley, near Challis and near Arco are participating and have agreed to “substantially change the way they graze.” The researchers are analyzing different grazing scenarios in 15 pastures, ranging from 2 to 10 square miles each.
Conway explained the study has shown some sage grouse behavior patterns can’t be discerned by studying small areas. They spent two years gathering baseline data under current ranching practices for each allotment. Beginning in the study’s third year, ranchers were asked to stop grazing a pasture as a control. Other pastures alternated between spring grazing and resting in even and odd years, or were grazed during both the spring and fall before resting.
“Compared to pastures that were rested that spring, we aren’t seeing a difference in sage grouse nesting success in (grazed pastures),” Conway said.
However, Conway’s data suggest tall grasses improve chick survival, though the lack of impact from cattle could be explained by some sage grouse choosing poor nesting locations. He’s seen no evidence that grouse have a preference for areas either avoided or grazed by cattle. Conway’s team will also include weather data in its analysis.
“The goal is to find where those tipping points are so policy can be set,” Conway said.
Karen Launchbaugh, director of UI’s Rangeland Center, who is studying grass utilization by cattle involved in the study, said some areas in each allotment have been fenced to compare the health of vegetation that’s been grazed against areas cattle can’t access. Though it’s too early to draw solid conclusions from the study, Launchbaugh is at least pleased there have been no “big red flags” suggesting cattle and sage grouse can’t coexist.
The study has a roughly $500,000 annual budget, funded by the BLM, IDFG, Idaho Cattle Association, Public Lands Council, Western Association of Fish and Wildlife Agencies and Great Basin Landscape Conservation Cooperative.
When sage grouse were under consideration for an endangered species listing, ICA Policy Director Karen Williams explained invasive species and wildfire were listed as primary threats and “improper” grazing was considered a secondary species threat. Nonetheless, Williams said grazing has been heavily regulated, despite a lack of “good scientific research.”
“We need the kind of information the agencies can include so they don’t feel like they have to restrict grazing,” Williams said. “We’re not scared of the science. We feel like the science is going to come out in our favor.”