WCS is working to restore free-ranging plains and wood bison at multiple locations across their historical ranges to ensure a future for wild bison. Our long-term vision is to restore large, free-ranging herds in extensive native habitats to facilitate interactions with other species and thus support the ecological recovery of bison across the full range of this species.
Up to 30 million plains bison (Bison bison bison) once roamed the Great Plains in herds and for millennia were the driving ecological force in the continent’s grassland ecosystems. The grazing patterns of free-ranging plains bison created a landscape mosaic of habitats grazed at different intensities, influencing natural fire regimes and providing habitats for hundreds of species of endemic grassland insects, 40 reptile and amphibian, 25 bird, and 18 mammal species. Bison also maintain grasslands by horning invasive trees, creating depressions that retain water by wallowing, and providing food for wolves and grizzly bears.
Larger than plains bison, the wood bison (Bison bison athabascae) is a subspecies of American bison that is specially adapted to live in northern meadows and boreal forest habitats. In the early 1800’s around 168,000 wood bison lived in Canada and Alaska . Their numbers are now so reduced that the wood bison is listed as threatened under the Canadian Species at Risk Act.
While today, there are an estimated half-million American bison that live in the Great Plains and boreal forests of North America, over 90% are on private ranches generally bred for meat production and restricted by fences. There are only about 20,000 plains bison and 10,000 wood bison that live in 62 conservation herds. And even amongst these conservation herds fewer than 15,000 bison are free-ranging and able to function ecologically. Ecological restoration will allow bison to fully interact with the many native species and ecological systems across their range, to be influenced by the forces of natural selection and to inspire and sustain human cultures, as they did historically.
In the 1800s, industrial-scale slaughter left fewer than 1,000 bison in the wild. In 1905, the American Bison Society (ABS) was established by WCS in response to the slaughter, to save the species from extinction. ABS activities included the relocation of bison from the wild to the Bronx Zoo in New York. The offspring of these bison were distributed to Wind Cave National Park, where their descendents persist today. In one of conservation’s forgotten success stories, sportsmen, ranchers, and conservationists restored wild bison in Montana, Oklahoma, and South Dakota.
Ecological Recovery of Bison and Grassland Birds
Understandably, there are few land managers experienced with bison in a conservation setting. As birds are great indicators of habitat quality, we are using bird species with specific habitat requirements as conservation targets to manage bison grazing at restoration sites and to monitor restoration progress. This work is taking place in the northern Great Plains of Canada and U.S. as well as the southern plains in the U.S. and northern Mexico.