Yellowstone Bison Herd to be Culled

Published January 20, 2016

The United States government released bison management plans for the Yellowstone National Park herd which includes killing or removing up to 900 wild bison from the park this winter as part of a continuing effort to reduce the number of animals’ migrating into Montana by reducing their population.

Bison management in Yellowstone each winter usually includes culling the herd to prevent migration out of the park as the bison forage for sufficient grass to sustain them through Montana’s harsh winters. However 2015’s planned cull of up to 900 animals would represent the largest number of bison removed in one winter since 2008, representing more than 18 percent of the current population of about 4,900 animals. 

Brucellosis Threat

Bison can carry brucellosis, a highly contagious, infectious disease that can decimate livestock herds, causing decreased milk production, weight loss, loss of young, miscarriage, infertility and lameness, potentially causing millions of dollars in losses. Roughly half of the park’s bison to be examined have tested positive for exposure to brucellosis. 

If bison leaving the park carry brucellosis, it could spread to domestic bison and cattle herds in the state, threatening Montana’s livestock industry’s brucellosis free status, making it hard to sell cattle from Montana to out of state buyers.

Since the 1980s, worry over brucellosis has prompted the killing of about 8,200 park bison. Under a 2000 agreement between federal agencies and Montana officials, the capture and slaughter of bison has become a regular occurrence.

Some Desire Alternatives

Yellowstone Superintendent Dan Wenk said in a statement the National Park Service was uncomfortable with the practice and interested in alternatives, such as sending disease-free animals to other public, private or tribal lands. 

“The park would gladly reduce the frequency and magnitude of these operations if migrating bison had access to more habitat outside the park or there was a way to transfer live bison elsewhere,” Wenk wrote in his statement. 

In late December, Montana Gov. Steve Bullock approved a plan that for the first time would allow hundreds of bison to roam year-round on about 400 square miles of primarily public lands west of Yellowstone. The proposal must be agreed to by the park, other federal agencies and American Indian tribes before it can go into effect. 

Hunt Still On

Even if this plan goes into effect this winter, it would likely have little impact on the hunts planned this winter as most of the population growth has been in herds that migrate into the Gardiner Basin north of the park, not near the park’s western borders where Bullock wants more tolerance for the animals.

“The governor’s decision wouldn’t change the number of animals, the goal of what we’re trying to take this year,” Fox News reports Sam Sheppard with Montana Fish, Wildlife and Parks as saying.

In recent years, Park officials emphasized preventing wandering bison from leaving the park via hunting just outside the park’s boundaries.

In the Winter of 2014/2015, 737 bison were removed, including 219 killed by hunters, 511 sent to slaughter or shot by government wildlife agents, and seven transferred into a government research program. Even with these efforts, the park’s herds remain at near-record levels.

H. Sterling Burnett, Ph.D., ([email protected]) is the managing editor of Environment & Climate News.