The recent bison exodus from Yellowstone puts 400 animals in peril of slaughter. As the Yellowstone bison population grows, their required acreage increases, meaning more land-use conflict as more animals move beyond the park border.
Once numbering in the tens of millions across North America, by the time Yellowstone National Park was created in 1872, there were less than two dozen wild bison remaining. Aggressive park management through augmentation and culling resulted in rapid population growth through the first half of the twentieth century. So much so, that regular culling became necessary to maintain a population that would coincide with the estimated carrying capacity of the park.
Opposition brought change in management policy. In 1968, ecological management was introduced leaving wildlife populations to self-regulate according to ecological conditions. But Yellowstone is not a self-contained ecosystem for bison. Without population control, bison growth has been exponential (see chart).
To maintain a healthy herd either habitat must be increased or bison numbers reduced. Bison lovers want increased habitat. Alternative land users see bison as a liability; they compete with livestock for forage and increase the risk of disease. The current bison management plan attempts to resolve the issue through hazing, capture, quarantine, hunting, and slaughter. All have been controversial and costly. Some land users have also been compensated to permit bison use on the land. Unfortunately, bison don’t abide by borders.
Most bison supporters pay little to sustain additional bison making it easy to lobby for more. But how many are enough? As long as bison numbers are allowed to increase they will continue to move beyond the allocated landscape. If bison are a liability to land users, the conflict will continue. If ranchers and other land users can realize a benefit from bison they will be more interested in sharing the land.
Source: 1902-1969 count and all removals available at www.buffalofieldcampaign.org/aboutbuffalo/wintercount1901-2000.pdf; 1970-2010 count available at: www.greateryellowstonescience.org/subproducts/118/281.