Study finds sage grouse doing better on grazed lands

Cattle and greater sage grouse seem to be getting along just fine in southeastern Montana, according to a recent Fish Wildlife and Parks study, and that’s a big deal. As sage grouse have been listed as a species worthy of protection under the Endangered Species Act, but precluded by higher priorities for now, western farmers and ranchers have been concerned about what the implications of such a decision might mean to the way they use the land. Environmentalists have long called for the elimination of cattle grazing on public lands where sage grouse live to preserve habitat for the birds, calling grazing destructive to the hiding cover needed to avoid predators and to forbs the birds eat. Why the two species are co-existing so well in southeastern Montana, however, is harder to pin down. Two very wet years fell within the four-year study period. Consequently, there was a lot of vegetation on the landscape. Typically, nesting success tends to be related to vegetation height, which would normally be lessened by grazing. But this study found that “nest success was higher for nests in pastures with livestock concurrently present (59 percent) than pastures without livestock (38 percent).” The study also found “no direct negative impacts (e.g., trampling) of livestock on nesting sage-grouse.” In addition, the study found that brood success in the first two weeks after hatching was better for those chicks that hatched in pastures with livestock (79 percent) than without (61 percent). Foster speculated the reason may be that “mean mama cows” chased off predators like coyotes or foxes. The presence of ranchers checking on their cows could also have lessened predation, she said. Unfortunately for sage grouse, coyotes and foxes weren’t the biggest predators. They were responsible for only about a third of sage grouse kills. The high predation rate on sage grouse by raptors (40 percent), however, was a surprise to Dale Tribby, supervisory wildlife biologist for the Bureau of Land Management in Miles City, who contributed to the study. “Sage grouse are usually eaten by something,” Tribby said, he just didn’t realize how many of them fell to the talons of golden eagles...more