Bison benefit prairie more than cattle, help the ecosystem (plants, birds, etc.) and make it more resilient to drought

Three bison on the American Prairie reserve in Montana (Photo by Louise Johns, The New York Times)

Iconic horns, massive bodies, and shaggy fur: the American bison is a commanding presence that some think the West needs to regrow and protect its once magnificent ecosystem. "Since 2001, American Prairie — formerly known as American Prairie Reserve — has been working to create a fully functioning wild prairie, complete with herds of bison thundering across the landscape and playing their historical ecological role," reports Jim Robbins of The New York Times. "Experts originally thought it would take a decade or so to restore the bison-driven grassland ecosystem that would, in turn, replenish native species, including numerous grassland birds, river otters, prairie dogs, grizzly bears and wolves — all of which have been eliminated or diminished, largely by farming and livestock grazing." Robbins notes that experts have had to expand their timetable to decades.

The Great Plains was once home to "between 30 million and 60 million bison," Robbins writes. "They were a 'keystone' species in a complex ecological web, creating a cascade of environmental conditions that benefited countless other species. . . . A long-term comparative study of bison and cattle on tallgrass prairie in Kansas showed that over about 30 years on land grazed by bison, the richness of native plant species doubled compared with places where cattle grazed, and the presence of bison made the prairie ecosystem more resilient to drought."

Wes Olson, a bison expert who worked to return the animal to Grasslands National Park in Saskatchewan for Parks Canada, told Robbins, “In virtually every ecosystem currently grazed by bison, all of the grassland songbirds are lining their nest with bison hair. It insulates and increases chick survival and egg survival by up to 60 percent.”

Bison advocates have had to reset their completion schedule multiple time and "a full-blown prairie ecosystem is still decades away, and it won’t be cheap: Dr. Freese, who is writing a book about the return of wildlife to the plains, estimates it is likely to cost several hundred million dollars," Robbins reports. But the ultimate goal is attainable: "Someday, the bison on reservations, American Prairie and nearby wildlife refuges in the United States and Canada, may become one vast herd, roaming across about 3 million acres."