Ask an Expert | When it comes to sage grouse habitat: Don’t sweat the small stuff

February 27, 2020

Would a sage grouse nest here? Photo courtesy of Rebecca Knapp, NRCS.

The paper featured in this Ask an Expert was one of the most cited in the Journal of Wildlife Management in 2020-2021. Congrats Joe!

When it comes to sage grouse conservation, Joe Smith, Working Lands for Wildlife scientist, says: “Don’t sweat the small stuff.”

Joe Smith has spent years thinking about what difference, if any, a few inches of grass makes to sage grouse.

It’s been thought for decades that microhabitat features, like hiding cover, are a key factor in determining the nest success of sage grouse. But after doing extensive research for his PhD that suggested otherwise, Joe wanted to dig deeper.

So, he conducted a meta-analysis (a formal, quantitative (often statistical) analysis of previous studies) of sage grouse nesting research. Using data from localized studies across the West from the past 30 years, it’s the first study of its kind to employ a meta-analytical approach to help resolve long-standing uncertainty around the role of fine-scale vegetation in nest success.

His recently published paper in the Journal of Wildlife Management, entitled “Are Sage-Grouse Fine-Scale Specialists or Shrub-Steppe Generalists?” revealed that commonly used management objectives for fine-scale vegetation structure in sage grouse nesting habitat were unrelated to variations in nest success.

Joe’s findings highlight a nagging problem in wildlife management: Researchers and land managers often work at different scales. A case in point is when scientists measure habitat within a few feet of a nest while land managers make decisions at the larger allotment and ranch level scales. But as Joe’s work suggests, merging these mismatched scales together into land management plans may not yield anticipated outcomes for conservation.

We sat down with Joe to learn more about his findings and how he thinks sage grouse habitat should be managed in the future and why.

How did you get interested in studying sage grouse?

When I got my start back in 2011, the sage grouse was front page news as a candidate for listing under the Endangered Species Act. There was an obvious desire to proactively conserve the species and keep it off the list because it would have such massive consequences for rural economies across the West. I have always been interested in the messier aspect of wildlife biology, where people are politically or emotionally invested in it. I liked that about it.

What’s the take home message from your study? 

My message to readers is to put down your yardstick and pick your head up because there’s bigger fish to fry than microhabitat features like grass height. Sage grouse management has, for decades, placed a huge emphasis on the importance of fine-scale structure of vegetation, especially its supposed role in concealing nests from predators. Our meta-analysis shows that sage grouse simply aren’t all that picky about these details. So, let’s stop sweating the small stuff and think big.

Contrary to the prevailing view of sage grouse as choosy specialists sensitive to slight variations in fine-scale vegetation structure, comparisons of nests to available sites among dozens of studies revealed that females pick nest sites nearly indistinguishable from their surroundings across the diverse sagebrush vegetation types found across their range. While shrub height and cover were almost always slightly greater at nests, herbaceous vegetation virtually mirrored availability. Figure courtesy of Joe Smith.

Were you surprised by what you found?

Not really. Sage grouse are found across a wide diversity of sagebrush vegetation communities that have little in common regarding their fine-scale vegetation structure. I’ve also spent way too much time hunched over sage grouse nests measuring vegetation. I could never shake the notion that every shrub looks about the same. Our findings back that up.

What did you learn about guidelines currently used by managers?

This was probably the most interesting finding from a management perspective. Microhabitat guidelines underpin most land management plans with the intention of optimizing habitat for sage grouse. If we’re going to ask managers to structure their decisions around perfecting habitat for a single species, then the targets or objectives we give them should provide some measurable benefit to that species. Habitats conforming to the nesting objectives for example should provide greater nest success. But that’s not what we found. We found most nesting habitats don’t meet habitat objectives, and those that do meet more of the metrics still don’t yield higher nest success.

Smith’s meta-analysis revealed that commonly used management objectives for fine-scale vegetation structure in sage grouse nesting habitat were unrelated to variation in nest success. About 30–40% of nests were successful regardless of how closely the vegetation conformed to these objectives. Figure courtesy of Joe Smith.

Why is management so focused on fine-scale vegetation measures?

Ecological patterns are notoriously scale dependent. That’s part of the complexity of wildlife ecology. But for years, we studied sage grouse habitat exactly the same way with exactly the same tools—a measuring tape, yardstick and quadrat. This provided biologists and managers with all kinds of information about local habitat relationships, but only at a single small scale. This information was incorporated into management guidelines because it was all we had at the time. Our findings now show that patterns observed at a fine-scale don’t hold up at larger scales, as we’ve always assumed they do. It’s the larger scales that land managers deal with. 

So, if it isn’t fine-scale vegetation under your boots, then what is it?

Sage grouse population declines are not a fine-scale phenomenon; they’re the direct result of the ongoing and large-scale loss and fragmentation of sagebrush country. Simply put, we must maintain large and intact expanses of sagebrush habitat that are free from fragmenting features. Proactive public lands policy that keeps oil, gas and renewable energy development out of our best habitats is a top priority in areas where those threats are present. Similarly, scaling up our response to big and persistent threats like conifer expansion, invasive annual grasses, cropland conversion and urban sprawl is imperative. These are the biggest drivers of landscape change, and if we don’t get ahead of them, we won’t have any grass left to measure.

Fine-scale measures of habitat suitability are inadequate to tackle large-scale and persistent impacts that threaten sagebrush landscapes. ©Artwork by R. E. Newton.

So, does this mean cattle can graze habitat down to the dirt? 

That’s a straw man argument. Nobody’s proposing doing that. Sage grouse are one species in a diverse biotic community, and the agencies and landowners who manage those ecosystems have a responsibility to manage rangeland sustainably regardless of sage grouse. In fact, if sage grouse went extinct tomorrow, reckless overgrazing wouldn’t be the alternative we would fall back on. Good grazing management is still important for maintaining rangelands that are resilient to fire and resistant to cheatgrass.

How do you hope this work changes sage grouse management?

I hope it shifts the dialogue from trying to perfect fine-scale habitat features like hiding cover and instead rallies people around developing solutions that reduce broad-scale threats to sagebrush ecosystems—things like a growing oil and gas footprint, the annual grass-wildfire cycle, piñon-juniper woodland expansion, and cropland conversion. We all have limited resources and an immense landscape to conserve. Strategic investment is essential. Recent science has opened our eyes to the magnitude of these problems, but it has also shed light on promising solutions.

Meet the Expert

What’s your favorite part of your job?

I’m a numbers guy; sounds nerdy, but I like sifting through data to find answers. Ask an interesting question, and let the chips fall where they may. I like to be surprised.

What are you working on now?

I’m working on identifying links between annual grasses, climate, and wildfire in the Great Basin, and looking for possible inroads where management can help break that cycle. Cheatgrass and other invasive annuals are by far the biggest threat to sagebrush ecosystems in the Great Basin. There’s nothing worse. We don’t have a handle on how to manage it or stop it right now. So, it’s something I feel strongly about and get a lot of satisfaction working on.

What do you like to do in your free time?

I spend a lot of time outdoors, cross-country skiing in the winter and backpacking, hunting and fishing the rest of the year.

For more information, watch Joe’s presentation at the Working Lands for Wildlife Symposium at the 2019 annual meeting of The Wildlife Society in Reno, Nevada.

This Ask an Expert was produced by Kylie Mohr, freelance journalist and environmental science and natural resource journalism master’s student at the University of Montana.

The Sage Grouse Initiative is a partnership-based, science-driven effort that uses voluntary incentives to proactively conserve America’s western rangelands, wildlife, and rural way of life. This initiative is part of Working Lands For Wildlife, which is led by USDA’s Natural Resources Conservation Service.