Study: Sage Grouse Doing Better on Grazed Lands
May 16, 2014

Cattle and greater sage grouse seem to be getting along just fine in southeastern Montana, according to a recent Fish Wildlife and Parks (FWP) 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 United States 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).

Lead FWP researcher Melissa 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.

"Sage grouse are usually eaten by something," Dale Tribby, supervisory wildlife biologist for the Bureau of Land Management (BLM) said, he just didn't realize how many of them fell to the talons of golden eagles.

The study's authors did not recommend predator control, however, noting that predation is a fact of life for all ground nesting birds, and that controlling avian predators is not possible due to federal law. Besides, "control of one type of predator often leads to unintended increases in other predator species," the researchers noted, as well as the fact that predator control is expensive and only effective in the short term in small areas.

Suggestions from the study that the BLM might consider included that restrictions on activities in sage grouse nesting areas be maintained until July 15 to ensure greater chick survival and a minimum 4-mile buffer around leks for "highly intrusive practices."

Other management recommendations from the study included maintaining large expanses of intact sagebrush habitat, utilizing rotational livestock grazing, implementing conservation efforts, minimizing project impacts and minimizing the potential for West Nile virus outbreaks where possible.

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