A bison advocacy group is opposing the killing of up to 900 bison exiting Yellowstone National Park’s northern boundary.

So far, nearly 300 bison have been captured and will be killed.

A Yellowstone official said removal is necessary to control the population, but the Buffalo Field Campaign in West Yellowstone and Gardiner, Mont., believes the park can support more bison than allowed by the agreement struck in 2000 by the federal government and the state of Montana.

Meanwhile, a Montana livestock representative said the bison must be separated from cattle to prevent the domesticated bovines from contracting brucellosis many Yellowstone bison carry. Brucellosis is a bacterial disease that often causes female ungulates to abort their fetuses.

Although uncommon in the United States, the disease also can be spread to humans from unpasteurized milk products or handling an infected reproductive tract or fetus.

Members of the Interagency Bison Management Plan (IBMP) agreed to a plan to remove 800 to 900 bison that migrate out of the park’s northern boundary this winter to reduce population growth and the potential for a mass migration into Montana, according to a Jan. 15 National Park Service news release.

“This winter, hunting in Montana is expected to remove up to 350 bison from the population, while an additional 500 to 600 animals that leave the park boundary may be captured and transferred to tribal groups for processing and distribution of meat and other parts to their members for nutrition and cultural practices,” the release stated.

The management plan includes the Park Service, U.S. Forest Service, Animal and Plant Health Inspection Service, Montana Department of Livestock, Montana Department of Fish, Wildlife and Parks, InterTribal Buffalo Council, Confederated Salish and Kootenai Tribes and Nez Perce Tribe, according to the Park Service.

There were approximately 3,500 bison in the northern herd and 1,400 in the central herd in August, according to the Park Service.

Under the interagency plan, the agreement is to maintain 3,000 to 3,500 bison in the park. “We do not feel that would compromise the genetics of the population,” said Al Nash, Yellowstone National Park spokesman.

The Park Service’s own study said Yellowstone could support 6,200 bison. The Interagency figure is not based on science or the land’s carrying capacity, but rather what the cattle industry wants, said Stephany Seay, media and outreach specialist for Buffalo Field Campaign.

Brucellosis infecting cattle is their concern.

“That is why we’re involved in this,” said Christian Mackay, executive officer for the Montana Department of Livestock in the Helena office.

There has been no known transmission of brucellosis from Yellowstone bison to Montana cattle, Nash said.

Fifty to 60 percent of Yellowstone bison are brucellosis-positive. Cattle haven’t been infected by bison because the animals are kept separate. Federal law mandates a domestic cow infected with brucellosis must be slaughtered.

Some cattle have contracted brucellosis over the last seven years in Madison (northwest of Yellowstone) and Paradise (north of Yellowstone) valleys, but Mackay said he is pretty sure elk brought the disease.

Bison should be allowed to live in the tens of millions of acres of national forest surrounding Yellowstone, Seay said.

They are allowed outside the park during the winter. The bison are driven back into the park near Gardiner on May 1 and West Yellowstone on May 15 to prevent their mingling with cattle, Mackay said. 

Seay estimated 250 bison had been captured, with 101 of those shipped for slaughter. She estimated another 80 had been killed by hunters Jan. 21. 

The area around the Stephens Creek facility, the site of capture operations, is closed to the public until further notice for safety reasons, according to the Park Service.

“Exact capture and slaughter numbers are unknown because, for the second year in a row, Yellowstone officials refuse to be open with the public about their bison operations, stating they will only give out reports every two weeks,” Seay said. “Buffalo Field Campaign has requested media tours of the Stephens Creek trap numerous times, but those requests have gone unanswered.”

The Park Service is considering a media tour, Nash said.  

“The Yellowstone buffalo are America’s last wild, migratory herds and the most important bison population that exists,” the Field Campaign states. “They’ve been added to the International Union for Conservation of Nature’s Red List for being ‘threatened with near extinction,’ and even Montana designates the species ‘in greatest conservation need’ with conditions ‘making [bison] vulnerable to global extinction.’”

The park’s bison are not necessarily the last free roaming herd. There are other smaller herds elsewhere, but Yellowstone bison have been around for thousands of years. Yellowstone bison have no cattle genes.

“And it certainly has the most robust genetics,” Nash said.

Many public and private bison herds contain evidence of past interbreeding with domestic cattle, according to the Nature Conservancy.

In the early 1900s, there were 26 bison in Yellowstone. The herd was supplemented with some Montana and Texas ranch bison. Since then the population has grown steadily.

“It’s well suited to propagate its species,” Mackay said.

The Park Service knows some disapprove the bison management plan.

“We’ve heard those criticisms, and we are taking steps to look at the possibility of a new plan,” Nash said. A new management draft plan will be out this year for public review.

The Park Service also is studying the feasibility of a program to transfer Yellowstone bison to locations outside the park to augment existing bison herds or begin new herds. At this time the law states that Yellowstone bison cannot be transfered to other herds or new pastures because of the potential to spread brucellosis, Nash said.

The bison need to be protected as though they are on the Endangered Species Act list. “I think people need to recognize what is going on in Montana and Yellowstone is tragic,” Seay said.