WEST YELLOWSTONE, Montana — Somewhere between 600 and 900 Yellowstone bison will be culled from the population this winter.
Most of those animals will likely end up dead, either taken by hunters or shipped to slaughter. Some will stay alive, sitting in corrals and being enrolled in the park’s brucellosis quarantine program.
Yellowstone National Park biologist Chris Geremia said the park estimates the population sits at about 4,900 bison now, based on two counts this summer. Geremia said removing between 600 and 900 animals would result in a decreasing population.
How many end up getting culled depends entirely on the winter migration — how many animals actually move north out of the park in search of forage. Geremia said people should expect a big migration at some point this year.
“No matter what the weather brings there will probably be a fairly substantial migration into the Gardiner basin,” Geremia said.
The winter plan was finalized during a recent meeting of the hodgepodge of state, federal and tribal government agencies involved in managing bison under the Interagency Bison Management Plan.
The group, which meets three times a year, typically finalizes the winter culling plans this time of year as hunts managed by seven tribal governments and the state of Montana get going. Already two bison have been taken by hunters, according to the Buffalo Field Campaign, an advocacy group that closely monitors the annual hunt.
The range of between 600 and 900 bison is the same goal managers set in three of the past four winters. It has come with varying results.
This winter’s plan includes putting as many as 110 bison into brucellosis quarantine, a process of isolation and repeated testing for the disease. The program is meant to produce disease-free bison that can be sent to the Fort Peck. Certifying the animals as free of brucellosis — a disease feared by the cattle industry — clears barriers to transferring live bison from Yellowstone to other places.
Fort Peck received two shipments of bison from the Yellowstone region this year and more may soon be on their way there. Ryan Clarke, of the Animal and Plant Health Inspection Service, said there are 14 cow-calf pairs at APHIS corrals near Corwin Springs that will be tested again this month and could be sent north soon after.
The two shipments earlier this year and the likelihood another will clear space for more bison to enter quarantine. If 110 were to be put in quarantine, park managers would likely have to capture at least double that amount and test each animal for exposure to brucellosis. Only those that test negative could go into quarantine, and biologists estimate about half of Yellowstone’s bison have been exposed to the disease.
APHIS and Yellowstone would split the quarantine bison, with some going to the park corrals near Gardiner and others going to the APHIS corrals near Corwin Springs. But there’s only so much room at the two facilities, prompting some officials to wonder how the program can expand in the future.
“There’s a capacity issue there,” said Cam Sholly, the superintendent of Yellowstone.