The thought of a fallen bison, the noble and proud American mammal, lying dead upon the ground may be a troubling image. For Yellowstone National Park (YNP), the death of these animals is sadly a necessary, common occurrence.

YNP must cull, or selectively slaughter, bison herds in the park in order to sustain the park’s ecosystem. Bison overpopulation leads to overgrazing, which can injure flora and throw off the delicate balance between plants and animals in the park. In addition, bison have few predators in the park, and those that exist (wolves and bears) are not present in large enough numbers to control the massive herds of bison. Finally, brucellosis, a zoonotic disease that can force miscarriages in cattle, is the main reason for the culling of bison in YNP.

Ranchers located near YNP are hostile toward the idea of free-ranging bison for fear that the bison will infect their domestic cattle. This concern is not without merit. Yellowstone officials from the National Parks website note that 60% of tested female bison in the park carry the disease. 

As a result, the park must find ways to limit the growing populations of bison. Bison management began in 1995, when the Interagency Bison Management Plan was put into effect. The National Park Service, Forest Service, Animal & Plant Health Inspection Service and Fish & Wildlife designed the plan to maintain a wild, free-range bison population in YNP while attempting to reduce the risk of brucellosis transmission and managing bison that leave YNP. This plan set a target of 3,000 bison in the park.

Currently, YNP officials cull, slaughter or quarantine and domesticate around 400-900 bison a year. Although some animals are slaughtered, they are not just left to rot. Instead, according to the National Parks Service, many of the culled animals are caught and transferred to Native American reservations to be slaughtered, where the meat is distributed among the tribes. In particular, The Fort Peck Reservation in northeast Montana assists YNP in managing bison populations while supporting Native peoples. 

In addition, YNP officials are setting aside over a hundred bison for a quarantine program within the park to be tested for brucellosis. If and when they are found to be disease-free, they will be used to start new bison herds or bolster the numbers of already existing herds. 

While YNP  officials have found no other alternative to bison management, groups like the Buffalo Field Campaign (BFC) work to end the culling of bison and advocate for the populations to be able to roam free.  According to the BFC, roughly 11,700 bison have been culled from the park population since 1985. The Bozeman Daily Chronicle stated that the BFC also claims that the quarantine programs will result in the domestication of a wild animal. 

While the BFC’s concerns about the well-being of bison are valid, they fail to see the severity of the situation. Montana’s current ecosystem relies on a carefully managed balance between human and non-human animal populations, and simply allowing bison to roam free in Montana would disrupt this cautious equilibrium. 

In addition, the management program has strengthened and improved herds, allowed Native American groups to hunt wild bison and given YNP officials the chance to protect bison. Bison who are kept in the park can be monitored, are protected from human contact and do not harm the health of domestic cattle. 

The management practices of YNP have been carefully refined since 1995 to preserve and protect the famous Yellowstone landscape while supporting one of only three genetically pure wild bison herds in the United States. The bison management program must remain in place if Yellowstone is to remain a nature lover’s paradise and Montana is to continue raising high-grade beef.

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