Last month, Yellowstone National Park officials announced that as many as 900 wild bison that graze in the park will be killed this winter, either by hunters or slaughter, to offset population growth. The cull has happened periodically since 1908, but this year鈥檚 number is the highest since 2008, when 1,726 bison were removed from the park, and the fourth highest of the past 46 years.
Park officials and bison advocates lamented the decision, saying it would be better to give聽the animals access to more land outside the park or transfer them (alive) to other public or tribal lands. But it鈥檚 not so simple. Ranchers oppose such an expansion for bison because female bison can transmit the disease brucellosis to cattle via afterbirth, potentially causing the cows to miscarry and costing ranchers money. There has never been a documented transmission of brucellosis from a bison to a cow, but the two sides view that fact differently:聽advocates say聽it's a reason to relax the restraints;聽the livestock community says it's proof the current system works. 鈥淚t鈥檚 a little like saying your dog鈥檚 never gone out of your yard, so why is there a seven-foot fence?鈥 says state veterinarian Marty Zaluski. Doing nothing鈥攏either killing them nor聽letting them roam鈥攚ould crowd the park with more bison than what is deemed manageable.
Ranchers and bison advocates have been locked in disagreement for decades, and the yearly cull is the result. But the Montana government may have just broken down a critical barrier between the two sides. In December, Governor Steve Bullock, a Democrat, 聽that bison would get their first swath of year-round habitat outside Yellowstone. The 400 square miles of mostly (96 percent) public land is expected to accommodate hundreds of bison, allowing them to roam and graze freely. In doing so, the state has looped聽in a third party: hunters.
鈥淚t鈥檚 a little like saying your dog鈥檚 never gone out of your yard, so why is there a seven-foot fence?鈥
Stakeholders on both sides of the argument agree that an increased hunting harvest is the most ethical way to control the herd鈥檚 population.听But it probably won't be enough to offset the need for a cull because聽hunting is only allowed outside the park聽and聽even a stellar harvest might only remove a few hundred more animals. (Hunters killed just over 300 this year.) One thing seems clear, says聽Jim Stone, executive director of the聽聽(ITBC), one of three Native American organizations that work with the government to manage Yellowstone bison:聽鈥淚 think it鈥檚 indicative of a change in mindset.”
The decision to open more land to bison could signal that Montana is聽closer to confronting聽the heart of the dispute, which is whether these animals are truly “wild.” The label doesn't have any bearing on how the animals are managed on the state level, but聽it's been a point of controversy since the initial settlement of聽the American West.听After decades of deadlock,聽it could be time聽to open up the bison range and manage issues as they arise, like we would with any other wild species.
As it stands, roughly 4,900 bison live in Yellowstone and they roam in two main herds. They are among the most genetically pure wild bison on earth, meaning they have not cross-bred with cattle, like most bison in the U.S. Perhaps because of that, they tend to survive and reproduce at exceptional rates. Come winter, some of them, including pregnant females, leave the snowy high country to graze at lower altitudes. Usually their migrations lead them into Montana, where they are managed by the state.
Management is necessary to preserve the herds. More than 100 years ago, rampant hunting and poaching left only two dozen bison in the park and nearly eradicated the species from the U.S. It took decades to reestablish the Yellowstone herd. As the species rebounded鈥攏umbering into the thousands in the 1980s鈥攎anagement became highly politicized.
Today, in addition to the debate about how much land to allow the bison, there鈥檚 dispute about how many bison constitute a healthy population. A 16-year-old management plan on the books鈥攚idely considered unscientific鈥攑uts the number at 3,000 bison in Yellowstone. Last spring, state and park officials said they were planning to draft a new plan, with more informed objectives. But it could take awhile for the plan to come to fruition, says Rick Wallen, the lead wildlife biologist for bison at . 鈥淭he first time around, it took 12 years and a few lawsuits,” he says.
Hunting may be the optimal method of population management, but with no guarantee as to how many animals leave the park each year, it remains unreliable.听Often hunters end up with few bison to chase for minimal periods on small swaths of land. 鈥淏ison behave just like any other wild species,鈥 Zaluski says. 鈥淲here there鈥檚 significant hunting pressure, they seek and reside in places where the hunting pressure doesn鈥檛 exist.鈥 This, in turn, has led to larger slaughters.
Yellowstone officials identify bison for 鈥渢ransfer鈥 (the preferred term for slaughter) after they wander, or are chased by workers on horseback, into so-called capture facilities on the outskirts of the park. Females, including pregnant ones, are prioritized for removal, while big bulls over the age of three are released, to be hunted later.听Once inside the facility, the bison wait to be picked up, often by the dozen, and driven under armed guard in a semi truck or livestock trailer to a processing plant. There they are killed, gutted, skinned, and butchered, then their skulls, hides, and meat are shipped to one of a handful of reservations that the park service has entered into agreements with to deliver 鈥渟urplus wildlife,鈥 as Wallen calls the unlucky bison.
The park service does not charge a fee for the animals; organizations like the ITBC and (CSKT) handle the processing and transport for their members, but the recipients must cover the cost. Recipients can range from homes for the elderly or poor to school lunch programs to a hunter who failed to land his own bison that year. A 500-pound bison could cost $750 when all fees are tallied.
It is up to the state of Montana whether to allocate more year-round habitat for bison. With additional habitat, some stakeholders believe hunters could harvest up to 500 animals a year, leaving far fewer, if any, to slaughter.听鈥淚t appears that鈥檚 the simplest solution, but in 20 years, it鈥檚 never happened,鈥 Stone says.
One more new development could play a bigger role than any of the politics. On January 18, the U.S. Department of Agriculture鈥檚 (APHIS) removed brucella abortus鈥攖he bacterium that causes brucellosis鈥攆rom its select agents list. Zaluski says this could allow researchers to finally create a more effective vaccine for the disease. (The current vaccine, RB-51, works only marginally well on cattle.) That would weaken ranchers'聽argument against allowing bison to roam among cattle.
Every other proposed solution鈥攃apture, slaughter, quarantine鈥攊s designed to minimize bison鈥檚 exposure to cows that graze on public land. But with the threat of brucellosis transmission neutralized, Yellowstone bison could finally reach a point where they are not only called wildlife, but treated that way, too.