During the early decades of the 20th century, the rangers and scientists of Yellowstone National Park saved the American Bison from imminent extinction. The vast herds of Bison that once roamed almost every corner of North America—as many as 60 million strong—had dwindled considerably by 1906, when rangers gathered the last two dozen Bison remaining in the park for study and conservation. Brought to the Lamar Valley, the small herd slowly grew in size. And today, thanks to the efforts of generations of naturalists, nearly 5,000 Bison roam freely, forming numerous individual herds in practically every section of the sizable park—from Lamar to Hayden, Tower Junction to Mammoth, the Madison plateau to the geyser area of Old Faithful, Yellowstone Lake to Canyon Village.
And people love Bison. Every year, millions flock to Yellowstone from all over the world just to see these magnificent creatures, symbols of the west and a living testament to the dedication of those who labored for more than a hundred years just to give them a chance to range free and wild.
So you can imagine how disheartening it must be for rangers to have to round up perfectly healthy Bison for slaughter. It’s a task they’re obliged to perform on a nearly annual basis. And this year, they’ve collected nearly 1,000 Bison of various ages to destroy. Including calves. In fact, the park has already dispatched 150 Bison to a slaughterhouse to meet its sad quota. Why butcher so many healthy animals?
The action stems from an agreement signed in 2000 to proactively manage the size of the herd and thereby prevent Bison from leaving Yellowstone (in search of food) and spreading Brucellosis to cattle outside of the park. Although some Bison do contract Brucellosis (as do elk, dogs, goats, sheep, caribou, and pigs, all of which can spread the disease), no documented case of a Bison spreading the disease to cattle has ever been recorded anywhere on the continent. Not in the United States. Not in Canada. Not one case. Not ever.
Moreover, the bacteria that causes brucellosis in cattle, B. abortus, can only be transmitted when a calf is born (live or stillborn), at which time an infected bison sheds the bacteria along with the placental sac. In other words, cattle would have to come into contact with the afterbirth (or aborted calf) to absorb or breathe in any still-latent B. abortus bacteria present in the afterbirth or stillborn calf. That is highly unlikely to occur in winter—when Bison leave the park in search of areas with less snow and more accessible food—and would certainly rule out Bull Bison as a B. abortus transmission threat. But, as a result of the agreement, Bison leaving the park have been gunned down by marksmen at point blank range despite the season or the gender of the animal.
Could the park relocate Bison as a way to maintain the size of the Yellowstone herd at the targeted number of 3,000 animals? It would like to (and that possibility is apparently being discussed), but that is not an option under the terms of the 2000 agreement. Were it a possibility, numerous parties—Native American nations, environmental organizations, and private philanthropists—have stepped up to offer alternate locations where the Yellowstone Bison could live isolated from contact with cattle and other livestock.
But until the parties negotiate a compromise solution, the current agreement compels Yellowstone—the world’s first national park, an institution whose mission is to protect indigenous species within its borders—to take part in a nearly annual slaughter of a creature it helped bring back from near extinction.
For more background on this sublimely unfortunate situation, please see Matthew Brown’s “Yellowstone bison sent to slaughter as park trims herd” and the park service’s “Bison Management” on the Yellowstone site.