Yellowstone National Park administrators are recommending the removal of roughly 900 bison next winter through hunting, shipments to slaughter and for research purposes.
The proposal represents about 19 percent of the park’s wild bison. It would be the largest cull of the Yellowstone herds since more than 1,600 animals were removed during the winter of 2007-08.
The removals are intended in part to relieve population pressures that periodically push large numbers of migrating bison into Montana during harsh winters. The animals are not allowed in many parts of Montana because of fears that they could transmit disease to livestock.
Whether next winter’s goal will be reached depends largely on weather conditions.
Fewer bison leave the park to graze at lower elevations during mild winters. With an above-average snowfall, park biologists predict that as many as 1,200 bison could migrate this winter.
This summer’s population count tallied 4,860 bison in the park. That’s about the same as last year, even after hunters and government agencies removed 640 bison from Yellowstone’s herds last winter, said Rick Wallen, who heads the park’s bison program.
“We’re trying to avoid these massive, big harvests, but we haven’t been able to meet our objective yet,” Wallen said. “If we had a relatively mild winter, we probably wouldn’t see a significant migration to the boundary until later on and that would make it a challenge to hunt the animals.”
An agreement between state and federal officials sets a target population level of 3,000 to 3,500 Yellowstone bison.
Wallen predicted next summer’s count would drop below 4,600 bison if 900 were taken this winter. If that removal goal is met for two years in a row, the population would be about 4,100 bison, he said.
Montana Department of Livestock Executive Officer Christian Mackay said his agency was encouraged by the park’s proposal.
“We think it will keep the population in check,” Mackay said.
Wildlife advocates say a better approach would be allowing bison into areas outside the park where they are now barred.
Livestock interests and some local officials have opposed expanding bison habitat.
Some of the bison proposed for removal next winter would be used for research. A U.S. Department of Agriculture experiment is using park bison to determine if an animal contraceptive can decrease the likelihood of bison transmitting the disease brucellosis to cattle.