Gunnison sage grouse are vulnerable to climate chaos
The dancing birds are especially susceptible to changing weather patterns, which is bad news going forward.
This story is a part of the ongoing Back 40 series, where HCN reporters look at national trends and their impacts close to home.
Gunnison sage grouse have much in common with Goldilocks – they like it not too hot, not too cold. Unfortunately for the strutting bird, climactic extremes are increasingly common in the West, and the impact has become all too obvious in the Gunnison valley, a western Colorado high-mountain basin, where the vast majority of the species live.
In the Gunnison valley, as in the Southwest at large, the winter of 2017-18 was one of the most serious droughts ever recorded. Dry winters, by themselves, are not automatically bad for sage grouse. The problems begin when drought persists into the spring, as it did in 2018. The sagebrush was low and dry. Without water, forbs on the rangeland failed to flower. That meant fewer insects, which young grouse eat exclusively. Chick survival rates were low.
Things might’ve been ok if a normal winter had followed. Instead, 2018-19 was one of the longest, coldest winters in decades. Feet of dense, wet snow covered the sagebrush, the grouse’s sole source of winter food. Cold, wet temperatures persisted into late May, well past when hens start to lay eggs. In these conditions, eggs can get too cold, and hens sometimes abandon nests. These back-to-back extremes are where things get very bad.
Despite concentrated local efforts, the Gunnison sage grouse population sits at its lowest since population counts began in 1996 — and the climactic extremes and habitat loss that caused a more than 60% population plummet over the past four years are only expected to get worse.
That things are grim for the Gunnison grouse is not for a lack of effort. In fact, there is a robust conservation regime in the valley, an interlocking network of local, state and federal oversight that’s taken shape in spite of the fraught politics that have loomed over the Gunnison grouse’s larger relative. The Gunnison species, which was recognized only in 2000, is smaller, with a more pronounced head feather that looks like a ponytail and slightly different mating dances.
A proxy for oil and gas drilling fights in the West, the Greater Sage Grouse avoided a full Endangered Species Act listing in 2015, thanks to a conservation compromise that the Trump administration is now dismantling. Like for the greater grouse, some environmentalists want an “endangered” listing for the Gunnison grouse, currently labeled as “threatened.” An “endangered” listing would trigger much more stringent federal oversight requirements, but according to local officials like Nate Seward, a Gunnison-based Colorado Parks and Wildlife biologist, these efforts would be less effective than the conservation work already underway.
Right now, state wildlife officials do the on-the-ground work of lek counts, habitat care and translocations. They enhance habitat on federal public lands and work with the ranching community. This involves conservation easements, land swaps and livestock reduction on grouse habitat. Community cheatgrass pulls and sagebrush planting events are common. A county committee reviews all land use applications that might impact the birds.
But for all their hard work, Gunnison valley conservation officials are worried. To continue population recovery, Seward spoke of intensifying efforts to combat cheatgrass, while ramping up efforts to restore wetland meadows grouse depend on. He pointed out that the wet 2019 means the sage stayed green abnormally late, so the chicks that did survive should thrive. He hopes to see a population bump next spring. Seward understands that an ESA listing fight may be imminent if the population remains low, but he believes in the conservation efforts already underway. He takes pride in the local attempt to save a species whose existence, by and large, depends on this valley, but he cannot control a changing climate.
Like its larger relative, Gunnison sage grouse are indicators of sagebrush ecosystem health. So if things are bad for the grouse, it’s a dire sign for the rest of the sagebrush steppe. Seward called erratic weather patterns the “new enemy.” Sitting in his office, which is cluttered with maps and shed antlers, he cautioned that 2019’s heavy spring snows complicated population counts, so they likely missed some birds. Even so, the trend is troubling. “In time, these extreme weather events will be more common,” he said. “And that’s not great for grouse.”
Like other lekking birds – the males put on displays during breeding season – the Gunnison sage grouse has inflexible behavior patterns. And the Gunnison grouse is considered extra specialized, since its range is so limited. Even compared to the greater grouse, it has an extreme lack of genetic diversity.
These factors, according to Jessica Young, a professor at Western Colorado University who identified the Gunnison sage grouse as distinct, put the species at risk for something called an “extinction vortex”: where “extreme environmental conditions coupled with a lack of genetic diversity can increase the vulnerability of small populations causing a rapid spiral to extinction,” she said.
Extinction is not imminent, but, given the rapid climactic changes of the past decade, the risk is real. The bird is also losing its habitat to cheatgrass. The aggressive invasive often brings fire, which makes the grouse’s situation still grimmer.
“I don’t want to say we’re in panic mode just yet,” Seward said, “but the Gunnison basin is experiencing some significant changes.”
This story has been updated.
Nick Bowlin is an editorial fellow at High Country News. Email him at [email protected] or submit a letter to the editor.
- Endangered Species
- Back40
- Wildlife
- U.S. Fish & Wildlife
- Birds
- Climate Change
- Wildfire
- Colorado
- Climate
