Bison may not have future on Great Plains

The Great Plains has functioned as an ideal habitat for the North American bison for thousands of years. But according to new research from South Dakota State University, the grasslands of South Dakota and North Dakota may no longer be the national mammal's model habitat by the end of the century.

Earth's climate has changed throughout deep history, with periods of both warming and cooling. Currently, the North American climate is seeing an increase in temperatures and variability in precipitation. That change is causing some species to shift their range as living conditions become unsuitable.

The research team's findings, published in Frontiers in Ecology and Evolution, suggest that the center of suitable climate conditions for the North American bison will shift from the Saskatchewan-Montana/North Dakota border significantly to the northwest, near the Alaska/Canada border, by the year 2100. While Canada and Alaska will become more suitable for bison, much of the contiguous United States and all of Mexico — once home to vast herds in the northern part of the country — will fall underneath the suitability threshold.

"Our findings demonstrated that much of the North American continent, where bison were largely distributed over the last 160,000 years, will have a much smaller suitable living condition range by the end of the century," said Alex Shupinski, postdoctoral researcher at South Dakota State University and the lead author on the study.

Recovered from near extinction

At one time, bison could be found in the rich grasslands everywhere between Alaska and the Gulf of Mexico with a population estimated between 30 and 60 million in the early 18th century. But overhunting, mass slaughter, novel diseases from livestock and human encroachment brought the population down to just 750 animals by 1889.

Since then, coordinated recovery efforts have brought the species back from near extinction, and today, there are roughly 420,000 bison found in tribal, private, public and nonprofit conservation herds. The four sectors make up what Jeff Martin, one of the country's leading bison experts and an assistant professor of bison biology and management in South Dakota State University's department of natural resource management, describes as the Bison Management System.