Hundreds of Yellowstone bison will be slaughtered, hunted or quarantined. Here’s why

Hundreds of bison from one of the last wild bison populations will be captured or slaughtered as they migrate out of Yellowstone National Park.

Between 600 and 900 Yellowstone bison will be culled from the population, according to a Yellowstone National Park news release. Most of those bison will be slaughtered or hunted, but others will be quarantined in corrals.

Bison migrate out of the park into areas of Montana in winter because there is less snow, making it easier to find food. But outside of the park, there isn’t enough room for bison to roam, officials said.

Five government agencies and three tribal groups came up with the Interagency Bison Management Plan to help control the bison population.

“In December 2019, the IBMP partners agreed to a 2020 winter operations plan that recommends removing 600 to 900 animals from Yellowstone’s estimated population of 4,900 bison,” a park news release said.

Last year, 460 bison were removed from the population through hunting or slaughter, according to Yellowstone. Ninety-three bison were transferred to the Fort Peck Reservation in 2019, the park said.

“Our goal is to build a better future for our national mammal,” the park said in a video.

Why are the bison being killed?

Officials say the goal of the plan is to make sure the bison population isn’t growing indefinitely, which could cause overgrazing and mass starvation of animals in Yellowstone. The bison population increases by between 10 and 17% each year, the park said.

Another concern is that bison also often carry brucellosis, a bacterial disease that can cause abortions or stillbirths in infected animals. It does not kill the animals, but they could infect nearby cattle if they migrate out of the park.

“For ranchers, brucellosis has an economic impact because it affects the reproductive rate and marketability of their animals,” the park said. “Brucellosis has been eradicated in cattle herds across most of the United States. Bison and elk in the Greater Yellowstone Ecosystem persist as one of the last reservoirs of infection.”

Are there alternatives?

Bison need greater access to land to be able to leave the park’s boundaries, officials said. The area where the animals can be hunted is small, and hunting has been ineffective at limiting the number of bison, the park said.

It’s against state and federal laws to move wild bison exposed to brucellosis, which removes relocation of bison as an option, according to the park. Additionally, fertility control methods are currently not affordable or effective for bison populations, the park said.

“Many people don’t like the fact that animals from a national park are sent to slaughter,” the park said in a video. “We don’t like it either. That’s why we’re working with our federal, state and tribal partners to expand the quarantine program.”