For park rangers, shepherding the country’s last wild bison herd like so many shaggy sheep is a nightmare; the beasts weren’t built to be fenced in. But Yellowstone officials say that if they don’t keep bison in the park, the bison will become buffalo meat. That’s because government livestock officials fear that bison, which carry a disease called brucellosis, may transmit the disease to cattle. (Brucellosis causes pregnant cows to abort, and the bacterium can cause undulant fever in humans, though not from eating cooked beef.) During this unusually harsh winter, nearly 1,200 bison–about a third of Yellowstone’s herd–have wandered down from the park’s high plateau in search of food, only to be shot or captured for slaughter. The animals have a bizarre dual status: inside the park, they are the protected symbol of the primal frontier. Once outside, the hulking, prehistoric-looking beasts are seen as dangerous vermin.
Buried in the ““bison wars’’ are serious public-policy questions. Who controls wildlife in the West? And how serious does a threat have to be before it can be eliminated with extreme prejudice? Park Service officials insist that Yellowstone’s wildlife is the property of the entire country. If the bison aren’t allowed to roam across boundaries that are political rather than ecological, park officials and conservationists say, Yellowstone risks becoming a gigantic, artificial zoo rather than a refuge where nature is allowed to take its course.
The Animal Plant Health Inspection Service (APHIS) in the Department of Agriculture sees the bison as a mortal threat to the livestock industry. APHIS officials insist that their agency’s $3 billion, 50-year-long effort to eliminate brucellosis from livestock is nearly complete. If wandering infected bison aren’t controlled, argues Jim Peterson of the Montana Stockgrowers Association, then the state could lose its ““brucellosis-free’’ status–which would wreak economic havoc on ranchers. To ensure that doesn’t happen, Montana gives its livestock agents a license to kill.
But this shoot-on-sight approach has its detractors, and not just from animal-rights advocates. For starters, there are no documented cases of bison giving domestic cattle brucellosis in the wild. ““The ranchers of this area view the possibility of brucellosis transmission from wildlife to cattle to be so insignificant that it poses no real threat to their interests,’’ co-wrote former Wyoming Republican senator and rancher Cliff Hanson in a letter to President Clinton. As it happens, bison aren’t the only critters that carry brucellosis. ““It’s a much more massive problem among the elk,’’ says Andy Dobson, a professor of ecology at Princeton University. The Agriculture Department’s insistence on zero risk for bison transmission is not only unrealistic, says Dobson, it doesn’t make scientific sense–especially since APHIS ignores elk.
So why not just shoot all the wandering elk, too? Because they are valuable to hunters, outfitters and the tourist industry. ““The wildlife lobby and user groups would explode if APHIS seized control of elk the way they have with bison,’’ says Joel Berger, a wildlife biologist from the University of Nevada, Reno.
For Yellowstone’s bison, the worst may be yet to come. March is traditionally the worst snow month in Yellowstone. And hungry bison gathering near the park’s borders may yet head out of the park en masse. Biologist Mary Meagher, who has studied the Yellowstone bison for decades, is concerned that the shootings combined with an unusually high natural winter kill could lead to a ““system crash.’’ Meagher says with a sigh: ““A truly nomadic wild animal is a difficult beast in the modern world.''
