Yellowstone's northern elk herd is doing well. Maybe too well.
by Thomas A. Lewis
The point of contact between the world's largest herd of migratory elk and 20th-century human development is frequently Yoshi Neff.
Neff lives in Gardiner, Montana, a village of about 500 people located just outside the northern boundary of Yellowstone National Park. Around mid-December, when winter snows cover their food sources high in the mountains of the park, thousands of elk migrate down the Yellowstone River valley in search of lush river-bottom grass. As soon as they step across the park boundary, they confront Gardiner. A barrier to the elks' movement? The elk don't seem to think so.
"You know the opening scene of [the TV series] Northern Exposure [in which a moose wanders through an Alaskan village]?" asked Neff one December afternoon last year just before the annual arrival of the elk. "That's nothing! We had two old bull elk, they were enormous, that for years spent most of the winter walking up and down Main Street. We called them 'Bones' and 'Tines.' Bones got all tangled up in my neighbor's Christmas lights one year and went around for weeks with the lights and wires dangling from his rack."
Bones and Tines have not been around for a few years, but in the winter of 1996-97 Neff had a close encounter of another kind. His relationship with his next-door neighbors was deteriorating because, says Neff, "they wouldn't keep their dogs out of my trash. Day after day I'd find my garbage spread all over the back yard, and they just insisted their dogs weren't doing it. Then one morning I started to go out early and there was this big old cow elk with a plastic garbage bag half pulled out of the can."
For all his problems with them, Neff remains an enthusiastic watcher of the elks' migration: "You ought to see them swimming the Yellowstone, the whole herd grunting and squealing and complaining, the cows swimming upstream from their calves to shield them from the current. It is spectacular."
Others are less sanguine about the presence of the elk. The northern Yellowstone herd has increased from fewer than 5,000 animals in 1968 -- a number that was maintained at that low level by savage culling -- to some 20,000 today, and the expansion has brought accusations of increasing conflict with human settlements, domestic animals and even the environment of the herd's National Park home.
The American elk, or wapiti, is not an easy animal to ignore; indeed, it has been the subject of heated debate since Yellowstone became the country's first National Park in 1872. The elk is the largest member of the deer family except for the moose -- standing five feet at the shoulder, weighing up to nearly 800 pounds and boasting antlers that spread more than five feet. Almost all American elk are found in the Rocky Mountains, where most -- eight herds in all -- spend at least some of their time in Yellowstone National Park. A few herds reside in Banff National Park in the western Canadian province of Alberta; the larger Roosevelt elk is found on the Olympic Peninsula of Washington and California's Redwood National Park, and there are smaller tule elk in central California.
Wapiti have large needs for food and territory. They will eat twigs and leaves, but usually prefer grass and spend most of their time in the open, ranging each day up to 4 miles from their daytime bedding areas to find good grass. Because of their relatively small rumens, elk need to eat frequently and take periodic rests to digest what they have consumed. A mature elk consumes 10 to 15 pounds of forage daily, which means that the northern Yellowstone herd requires around 100 tons of plant material every day.
This expansive size -- of the animal, its appetites, and the Northern Yellowstone herd -- is the basis for a steady drumbeat of controversy, with charges that the elk are devastating the environment both inside and outside the national park. From Gardiner north, a narrow wedge of mostly private land brackets the Yellowstone River between two enormous blocks of the Galatin National Forest. Here the elk are no longer treated as untouchable national treasures. In the National Forest they are just another resource, sharing the grass with domestic cattle and attracting hunters by the thousands every year.
While few elk are tolerated on privately owned grazing land, and no cattle graze within the national park, in the national forest elk and cattle share resources. Cattlemen with permits may graze their cattle on forest land from June to September, while the migratory elk herd uses the land from December to May. "We manage the cattle-grazing to leave about 50 per cent of the forage, and maintain all grass species, for the elk," explained forest service biologist Marion Cherry. "We are not particularly worried" about the state of the grazing lands in the national forest, biologist Cherry said last winter. The animals "generally are not overgrazing the land."
The grazing of cattle on the elks' range has an impact that goes beyond competition for the grass; there is a social problem here. A 15-year study in Montana found that by a two-to-one margin, elk prefer not to share their habitat with cattle. Even after livestock have been removed from grazing allotments, elk seem reluctant to make use of areas that have been grazed and trampled by cattle.
The disdain is returned by cattlemen, who regard the elk as little more than pests. The Montana Farm Bureau has "concerns" about the northern elk herd, according to information director Lorna Frank Karn. "The numbers of animals inside the park needs to be managed, reduced. They're overgrazing the park." And when they come north onto private property, they "get into hay piles, get over fences." Asked what should be done about that, she had a ready answer: "Our members should be compensated for damages." By whom? "Whoever owns the elk."
If the elk are an annoyance to one sector of the area's economy, they are vitally important to another -- hunting. There are two elk-hunting seasons every year in southwest Montana, one in November and another in January and February. The hunts attract sportsmen from all over the world who spend substantial amounts of money for lodging, meals, transportation, guide services and equipment.
The Montana Department of Fish, Wildlife and Parks sets the hunting seasons and limits with a view to the maximum sustainable harvest of the herd, taking into account a variety of factors including the elk population and the condition of the animals and their range. The state agency is not worried about the condition of the winter range -- "it is not necessarily overgrazed," said Tom Lemke, area wildlife biologist for Region 3. But it is concerned about "the trend to increasing numbers and to expanding distribution. The animals are using and extending the northern extreme of their range more and more." Lemke said the permitted harvest of northern-herd elk during the late season (which affects migratory, as opposed to resident, elk) had been increased every year since it was started in 1976, to an all-time high of 3100 in 1997.
The animals themselves seem to know there the boundary is and what it means. "Inside the park, in the summertime, I've seen a cow walk through a group of people to get to a patch of grass," said Don Despain, a research biologist at the park for 25 years and now an ecologist with the U.S. Geological Survey. "Elk outside the park run from humans."
However, it is the effect of the elk herd on its home environment, within the park, that has drawn the fire of its most persistent accuser, Charles Kay of Logan, Utah. Kay, an adjunct assistant professor of political science at Utah State University, calls the National Park Service's stewardship of the elk (in the title of a forthcoming book) "Ecological Malpractice." Kay insists that the burgeoning elk population has destroyed thick stands of aspen and willow that grace old photographs of the park, with consequences that include severe streambank erosion and severe declines in the numbers of beaver and deer. Other critics maintain that the park's grasslands are overgrazed.
Any appraisal of these charges must begin with the events of 30 years ago, when the park service charted a new and fateful course for the elk. Scientific advisors had concluded that the habitat of the northern elk herd could support no more than 5,000 animals, but the herd did not know that, and every year increased its numbers prodigiously. For decades the excess animals had been shipped to other elk ranges to establish herds there, but the method had worked so well that by the late 1950s there was no further demand for emigrant elk.
According to John Varley, who has been the Yellowstone park's chief scientist for 15 years, "the creed of the herd managers of the 60s became, 'We've got to kill 'em to save 'em.'" For the good of the herd, park rangers "killed them by the thousands every year. It got pretty ugly, and it got on television. The public was outraged and the Congress reacted. The country made what you might call a bio-political decision not to do this any more."
But if the rangers couldn't shoot the elk, someone else had to do it. A new park superintendent (Jack Anderson) and a new chief scientist, Glen Cole, were brought in, Varley explained, "to open up the park to hunting. But it didn't work out that way." Don Despain, who was recalled that "Glen Cole asked to see the data showing that the park had been overgrazed before the culling started. There wasn't any data."
What Cole found, Despain explained, were assessments done by commercial range managers, using the standards of managed pasture for fenced cattle, that in Cole's view had nothing to do with the health of wild rangelands, which grow and are grazed in completely different ways. Park scientists have since determined that elk stimulate the growth of the grasses on which they graze, tilling and aerating the ground with their hoofs and fertilizing growth with excreted nutrients.
Furthermore, Cole knew about some important experiments on animal populations that had been done in the 1950s. As Varley described the procedures, researchers put a breeding pair of rats in a cage with a huge supply of food. Every day they gave the rats the same amount of food, expanding the cage but not the food supply as the rats propagated. "What they found," explained Varley, "was that as the rats approached the limits of the food supply they controlled their own numbers." Not by starving or fighting, but in more subtle ways: "lowered reproductive performance -- fewer pregnancies, fewer live births -- and a slightly increased rate of mortality among the very young and the very old. A whole array of biofeedback mechanisms kicked in to stabilize the population."
It was called natural regulation, and Cole thought it might work for the elk. "Maybe we don't need to shoot them," he said, "maybe they will reach dynamic equilibrium." The herd managers backed off, no hunting was permitted in the park, and in ten years the herd reached 12,000 animals and stabilized.
Then, in the 1980s, things got much better for the elk. For a full decade the winters were dry and mild, the summers wet; forage was abundant and death rates low. Where there had been no public land north of the park except for the Gallatin National Forest, ten thousand acres of grazing land was bought and set aside for wildlife. Hunting pressures on the herd were eased: Montana Fish and Wildlife eliminated the "firing line" at the edge of the park where hunters had opened fire as the elk stepped across the boundary, establishing a buffer area and moving the hunters back; and they changed the late hunting season to a series of four-day shooting periods, replacing the former six-day-a-week pressure. The population of the northern herd increased to 20,000, where it has remained since (except for 1988-89, which saw severe fires in the park and a savage winter).
For more than 15 years, Charles Kay has campaigned against the Park Service's elk management policy as not just a mistake, but a conspiratorial heresy. "They take the view," he said recently from his Utah office, "that when the park was established it was a pristine wilderness untouched by man, teeming with wildlife. They regard the coming of Europeans as evil, and insist they have to remove human influence from their ecosystem."
The result, in Kay's view, is an elk population burgeoning out of control at the expense of the ecosystem. For evidence he turns to 19th-century pictures showing abundant stands of aspen and willow where none can be found today because, Kay says, the elk have nibbled the shoots by which these trees propagate. He also points to a series of fenced experimental plots called exclosures scattered throughout the park.
One of them, located a thousand yards or so from park headquarters at Mammoth Hot Springs, is an 8-foot-high woven wire fence that encloses five acres of 12-foot aspen trees, widespread willows and underbrush so thick a person cannot walk through it. The contrast between the so-called Mammoth Exclosure and its surroundings is stark. Outside the fence the conifers are widely spaced and it is hard to find an aspen, willow tree or a woody shrub. According to Kay, the exclosure demonstrates what Yellowstone would look like today if it were not for the elk.
One day last winter, in a book-littered office in the former cavalry outpost that houses park headquarters at Mammoth Hot Springs, John Varley gazed through tall old windows at the snowswept ranges of Yellowstone and considered the elk controversy. "You can make something theological and dogmatic out of natural regulation," he said, "but that's not what it is." You can also oversimplify complex biological situations, and that's what he thinks Charles Kay has done.
For one thing, Varley said, "the exclosures are among the more unnatural things in the park," and make a point about biological diversity that Kay has missed. "Plants, including aspens and willows, occur with about the same frequency inside and outside the exclosures, the differences are in the size of the crown." Moreover, Varley added, "We are losing native plant diversity inside the exclosures. Charles Kay published the data and we spotted the trend."
"Something is going on with the park's woody riparian vegetation and aspen," Varley admitted. But there is more to it than overgrazing. When the 19th-century pictures showing the lush willow and aspen growth were taken, the Northern hemisphere was emerging from the 350-year-long Little Ice Age, during which the Yellowstone climate was much wetter and cooler than normal. In the century since, annual rainfall in the park has dropped from more than 20 inches to as little as eight inches. "This is a semi-arid climate now, and aspen and willow are water-loving plants." You can still find them flourishing, he insisted, but at higher elevations where there is more rainfall.
"If these animals have outgrown their resources, then where are the malnourished animals?" asked Varley. "The fact is these animals are in fine condition." Moreover, should they find food supplies growing short, the response would not necessarily be starvation, but a form of birth control. "Cows with a lower than average amount of body fat do not become pregnant."
All is well with Yellowstone and its elk herds, Varley and his scientists believe, because they are adjusting to each other in ways far more complex and subtle than humans yet fully understand. Under constant criticism, and threat of official review, they retain a sunny confidence in the ability of natural regulation to handle almost anything. What will happen if wolves are successfully reintroduced? A slight reduction in the elk herd. What would happen if there were no longer a hunting season? "Nothing," Varley insisted, natural regulation would take its place.
What would happen to the elk if there were no longer a Yellowstone National Park? To that scenario Varley has a different response. "That," he said flatly, " is unthinkable."