The drive to produce biofuels adds to the pressures on vulnerable prairie chickens
by Peter Bronski
© Joel Sartore/joelsartore.com
Brian Obermeyer stands on the crest of a high, rounded ridgeline looking out across the vast expanse of the largest unbroken stretch of remaining native tallgrass prairie in the United States. “Sometimes it’s so green you could swear you’re in Ireland,” he says. “The chlorophyll almost hurts to look at.” It is a landscape completely devoid of trees, save for the valley bottoms that weave between the ridgetops.
These are the Flint Hills of eastern Kansas. Here the soil is shallow, underlain by limestone and chert (the “flint” for which the hills are named), which resisted the plow that overturned, subjugated and cultivated much of the rest of the Great Plains. In place of agriculture, a culture of ranching and grazing took root, making the Flint Hills an island of prairie amidst a sea of cropland. As a result, this vista—native tallgrass prairie that extends to the horizon—looks largely unchanged from when Zebulon Pike led his expedition through these parts in 1806.
We’re at the 11,000-acre Tallgrass Prairie National Preserve, and for wildlife conservationist Obermeyer, this is his baby.
“Up here, you can hear yourself think,” Obermeyer says, interrupting a silence otherwise broken only by the breeze and the chirping of birds. “Except in spring,” he adds. “Then you’ll hear the booming of a chicken.”
It’s the chickens we’ve come here to see—more specifically, the greater prairie-chicken, and if we’re lucky, the lesser prairie-chicken, too. Both members of the grouse family, their populations and ranges are on the decline, and I’ve come to learn why.
While many factors are responsible, much of the cause can be attributed to corn crops replacing prairie on the plains. Historically, corn has been grown for two reasons: as food for people and as feed for animals. But now, there’s a third reason—corn as fuel—and it’s driving a new set of pressures on the prairie-chicken.
“Keep your eyes open for chickens,” Obermeyer tells me, as a Henslow’s sparrow flits across the grasses. “They’re out here.” This corner of the preserve, in fact, is home to seven documented leks, the areas where males strut their stuff for the “ladies” during the spring mating season, with 64 individual birds or more. We climb into Obermeyer’s pickup, rumble along a gravel road and keep our eyes peeled. Then, we flush one. A greater bursts out of the dense grasses to my right, flies maybe 150 feet, then dives back into the cover of the prairie and disappears.
Arguably, no one knows more about the plight of the prairie chickens than Robert Robel, professor emeritus of environmental biology at Kansas State University in nearby Manhattan, Kansas. He began studying the chickens in the early 1960s, at a time when not much was known about either species, and few researchers were focused on them. Robel’s been at it ever since, giving him a long-view perspective on how life has changed for the chickens.
Greater prairie chickens were once widespread on the Great Plains from Colorado and Kansas north to the Canadian border. Lessers, meanwhile, have always had a more restricted range, bound to a relatively small pocket of prairie where Colorado, Kansas, Oklahoma, Texas and New Mexico come together on the southern Plains. Both, to different degrees, are utterly dependent on a mosaic of prairie—sand sagebrush, tallgrass, shortgrass.
Robel has seen both species suffer. “At one time, Kansas had more greater prairie chickens in the state than there were in the rest of the world,” he says. Since the 1960s, however, their populations have declined by 80 percent. The lesser has less than 10 percent of its original range in the state available. What’s more, when Robel first began studying the chickens, 60 percent to 70 percent of nests were successful. “Now we consider an area to be super if it has a 40 percent success rate,” he says. “But most areas around here are down to 15 percent to 25 percent success, which does not sustain a population.”
Robel adds that what he’s seen happen in Kansas is also the case across the Midwest as a whole. As a result, the greater is listed as vulnerable by the International Union for the Conservation of Nature, and the lesser is a candidate for listing as a threatened species under the Endangered Species Act.
The marked prairie-chicken decline all boils down to one fundamental problem: “Too many people putting too much demand on our prairie ecosystems,” Robel says. Or what’s left of those ecosystems. The overwhelming majority of America’s prairie was long ago converted to monoculture agriculture, leaving little native prairie behind. For example, just 4 percent of the nation’s native tallgrass prairie remains
Couple that habitat loss with another compounding factor: “Prairie chickens are very sensitive to human activity and to any kind of degradation of prairie,” says Robel. A house, a highway, a power line, a wind turbine, a nearby golf course—any of these human intrusions can have a detrimental effect on the chickens. “Habitat loss may not be physical loss,” Robel explains. “If habitat is beautiful for quality, but right next to one of these intrusions, it doesn’t destroy the habitat, but it does decrease its use by prairie chickens.”
Yet, at the same time, this extreme sensitivity to both quantity and quality of prairie habitat makes chickens a great indicator of healthy prairie ecosystems.
“Native prairie habitats are some of the nation’s most imperiled ecosystems, and the species that they support, particularly grassland birds, have all seen enormous declines over the years,” says Aimee Delach, who works on agriculture, renewable energy and climate change at Defenders of Wildlife. “Because they are so sensitive to any kind of human incursion, from agriculture to roads to power lines, the presence of prairie chickens tells us we are looking at very high quality habitats, the top priority places to protect from additional disturbance.”
As interest in alternative and renewable energies soars, corn-based ethanol has become a new, major player in the corn market. According to the Renewable Fuels Association, an ethanol industry group, total U.S. ethanol production was just 175 million gallons in 1980. In 2008, production topped 9 billion gallons, accounting for one quarter to one third of the corn harvested in the country.
But while corn-based ethanol at first seemed like a good idea—it was envisioned as an alternative “biofuel” that promised a more environmentally friendly emissions profile than petroleum-based fuels—the reality isn’t so rosy. Just ask David Tilman, regents professor of ecology at the University of Minnesota. He points out that only about 20 percent of each gallon of corn-based ethanol is “new” energy. The rest is “old” fossil energy needed to produce the ethanol–diesel for the tractors, natural gas for the fertilizer and fuel to run the ethanol refineries. What’s more, “if every one of the 70 million acres on which corn was grown in 2006 was used for ethanol, the amount produced would displace only 12 percent of the U.S. gasoline market,” he wrote in a piece for The Washington Post.
Tilman has spent the last 25 years studying the prairie, but in the last five years, has felt compelled to enter the debate about biofuels, largely because of his interest in biodiversity. “Why do we propose growing monocultures for biofuels?” he asks. Tilman and his colleagues have done research on what he calls “low-input, high-diversity grassland biomass,” and found that bioenergy yields from a grassland comprised of a mix of 16 species was 238 percent greater than a monoculture such as corn.
And yet, farmers insist on growing more corn for biofuel. In 2008 U.S. farmers planted 86 million acres of corn, the second-largest area since 1949, according to the U.S. Department of Agriculture (USDA). Growing more corn means two things: using drought-tolerant varieties and tapping aquifers for irrigation to push corn into areas of prairie that have never seen the plow, and pulling former agricultural lands that have been rehabilitated and restored to prairie out of the Conservation Reserve Program (CRP) and returning them to corn-based agriculture. “It’s a disturbing trend,” Tilman says.
The CRP is often heralded as the greatest environmental success story of U.S. agriculture. Administered by the USDA’s Farm Service Agency, eligible farm lands are enrolled in 10- or 15-year contracts and receive funding to undertake “approved conservation practices,” which almost always includes planting with diverse native grass mixes that functionally help to restore large sections of prairie. Typically, farm lands that are abandoned, marginal or no longer profitable are enrolled, and in total they add up to a serious chunk of real estate. As of last August, nearly 34 million acres were enrolled in the CRP (roughly 40 percent as many acres as were planted in corn).
“What if we restored more of these lands to high diversity systems?” Tilman wonders. “Once restored, we can use them for bioenergy production at the same time that they might provide valuable habitat.” Tilman thinks just such a scenario might be possible, even while accommodating the prairie chicken.
With corn prices remaining high, it’s a hard sell. Worse, more than half of the CRP acres are currently due to expire in coming years, and farmers may be reluctant to re-enroll when they see visions of corn ethanol dollar signs in their fields. Federal and state governments, meanwhile, see corn ethanol as a potential boon for rural economies and support production despite questionable environmental benefits. In fact, federal corn ethanol subsidies total some $5 billion annually, and state subsidies amount to no small piece of change, either.
Even so, Tilman remains “hopeful we’ll find a major win-win, for the environment and for society,” with prairie-chickens the beneficiaries, rather than the victims, on the prairie.
I leave the tallgrass prairie of eastern Kansas behind and head west, to the shortgrass prairie of the High Plains and the 18,000-acre Smoky Valley Ranch. The Smoky Hill River snakes its way west to east through the property, sitting below a series of bluffs known as the chalk badlands. Here, the grasshoppers grow to the size of hummingbirds, a sign of the rich, abundant insect life that serves as the main food source for the chickens. There’s also sand sage prairie, a favorite of the lesser prairie chickens.
I’m not lucky enough to see a lesser during my visit, but Rob Manes, a local wildlife biologist, assures me they’re here. And the fact that lessers can be found on the ranch is an indicator that, ecologically, life here is good.
Manes and I drive out to a lonely stretch of dirt road at the south end of the ranch. To the northeast, a herd of bison roams across the banks of the Smoky Hill River on the ranch, just east of some sand sage prairie favored by the lessers. Immediately to the west, an equally large parcel has the look of shortgrass prairie—land restored to its current state under CRP. To the south, a field was recently plowed—“broken out,” as Manes says—pulled from CRP and destined for corn next season.
“Corn ethanol has done bad things,” Manes says, squinting into the harsh sun. “It was a bad idea.” But he’s still optimistic about the prairie chickens’ chances.
Robel’s view is darker. “The birds will survive,” he says. “But their numbers will never go up to what they were 25 years ago. That is lost. They’ll survive at lower population levels.” In short, he says, prairie-chicken numbers won’t recover unless we back off the prairie and depopulate the central part of North America, “which won’t happen.”
But then there are places like Smoky Valley Ranch and the CRP lands just to its west and protected native prairie at places like the Tallgrass Preserve, which hint at a future for the Great Plains that just might sustain healthy chicken populations, even as America’s Breadbasket feeds—and now fuels—us.
Peter Bronski is an award-winning writer from Colorado who frequently covers environmental topics. His work has appeared in more than 60 magazines.