Sage grouse conservation is a balancing act.
With the birds’ numbers still dwindling, wildlife managers responsible for setting annual grouse hunting guidelines must account for a range of threats, from human-caused habitat loss to the droughts and wildfires made worse by climate change.
Wyoming is home to roughly 37% of the world’s greater sage grouse, the more widespread of the two sage grouse species. The birds thrive in “big, flat, rolling landscapes of sagebrush,” which are abundant across the central part of the state, said Jeff Beck, a professor of wildlife habitat restoration ecology at the University of Wyoming.
For more than a decade, the state has also seen the region’s highest annual sage grouse harvest, with the total estimated take hovering around 10,000 birds per year.
Of Wyoming’s four sage grouse hunt areas, two — those in the southeastern and far western parts of the state — are closed. The northeastern hunt area opened for three days in mid-September. And the biggest hunt area, stretching from Colorado to Montana and encompassing the central and southwestern parts of the state, offered a 13-day grouse season this year. Restrictions for both open areas were the same: a two-bird daily limit and a four-bird possession limit.
According to Beck, it’s a pretty good system.
Beck is the co-author of two recent studies on sage grouse management. The first compiled grouse hunting regulations, dating as far back as 1870, from 11 Western states and two Canadian provinces. The other analyzed the impacts of hunting regulations on grouse population growth, with mixed results.
Hunting isn’t a big sage grouse research topic. Most recent studies have focused on habitat loss, habitat selection, monitoring techniques and disease, Beck said.
“But hunting was kind of going on in the background,” he said. “And maybe even because it was usually done in populations that were larger, not the smallest ones necessarily, people, maybe, were more confident that it wasn’t having a big impact.”
Of the 11 states with sage grouse populations, seven currently hunt the birds, but hunting data from those states hadn’t been consolidated. “We have a history of that information and it wasn’t really put together in one place, and we saw that as a real need,” Beck said.
In general, the researchers found, declining sage grouse numbers have been driven primarily by habitat fragmentation and loss. Because the birds tend to avoid human disturbances, energy development infrastructure like roads and power lines bisects their existing habitat, while wildfires, drought-driven food scarcity and the incursion of invasive plants also push them into smaller areas. Hunting, though still impactful, has had a less marked effect on populations.
While sage grouse hunting regulations and closures have been in use for more than a century, they became more refined as data collection improved. State wildlife agencies have been particularly responsive to the birds’ declining numbers over the last 25 years, including by reducing bag limits, delaying the grouse hunting season and limiting open areas, Beck said.
“At some level of hunting sage grouse, we can influence their growth rates, and that can be really impactful on the population,” he said. The researchers found that states’ proactive strategies have largely prevented excessive population impacts from hunting, though the efficacy depends, in part, on population size.
Smaller sage grouse populations, like those in Wyoming’s two closed hunting areas, are especially vulnerable to environmental disturbance. The studies found that many small populations continued to struggle even after hunting closures — though the restrictions alleviated added mortality from hunting, Beck said.
But according to Beck, among larger and more stable populations, effective management can still allow for modest sage grouse hunting. And so far, he said, Wyoming’s conservation practices seem to be working.
“If we hunt the birds, then we’ve got people that are more interested in them,” he said. “And if there’s a problem, then the state can — that’s the first thing they can do — is restrict hunting season, to limit any chance that there’s going to be additive mortality.”