How bison are boosting biodiversity in the United States

Certain sounds are ancient, like the thunder of bison hooves across the prairie that turn the Great Plains into a giant drum. The American bison, our national mammal, was hunted to near extinction beginning in the early 1800s, and by late that century, less than a thousand remained.

The largest land-dwelling mammal in America, bison aid in balancing and maintaining a healthy ecosystem and help to create habitat for many species, including plants and birds. Their hooves aerate the soil, dispersing seeds and helping plants to grow.

Widespread restoration of bison to Northern Great Plains Tribal lands can help support food sovereignty and aid in the restoration of the prairie ecosystem, according to a new study, a South Dakota State University press release stated. Impacts on agricultural systems due to climate change may also be reduced by the presence of bison.

The study, “The Potential of Bison Restoration as an Ecological Approach to Future Tribal Food Sovereignty on the Northern Great Plains,” was published last month in the journal Frontiers in Ecology and Evolution.

“The buffalo is important to Indian communities, to our people culturally and ecologically to our lands,” said the president of the InterTribal Buffalo Council and Blackfeet buffalo manager Ervin Carlson, the press release said. “We know bringing them back will not only heal our people but also help us with the changes we see on our grasslands due to drought.”

Once, 30 to 60 million bison traveled across the Great Plains and were a main source of hides and meat, driving the economy of many Plains Indian Tribes. In an attempt to destroy the Tribal members’ livelihood, mass hunting of bison was encouraged by the U.S. government. As bison numbers dwindled in the late 19th century, the Tribes lost their main source of food and were driven onto reservations.

“The herds today are small and isolated. Today there are about 350K Plains bison in production herds, 30K in public herds and about 20K bison in tribal herds,” Hila Shamon, lead author of the study and a landscape ecologist and mammalogist at the Smithsonian Conservation Biology Institute, told EcoWatch in an email.

“Bison are a social species and rely on their herd to survive; an evolutionary strategy to maximize fitness. They group together for predator vigilance, collective foraging and learning,” Shamon said.

Bison are “megaherbivores” — large herbivores that weigh more than 1,000 kilograms — and are important contributors to the grassland system of the prairies, South Dakota State University reported. The physical impact of bison and other animals on the environment modifies it in such a way that it creates habitat for different species.

As they graze, wallow and trample, bison make the landscape more habitable for hundreds of prairie species in different ways.

In the wake of the bison’s grazing, grasses of differing heights provide birds with nesting grounds, according to the World Wildlife Fund. Some birds even line their nests with bison fur.

As the great bison wallow, they create holes that fill up when it rains, turning their wallows into amphibian breeding pools and water troughs for other prairie species. Several rare and medicinal plants also rely on these indentations in the land to grow.

“Bison’s movements drove nutrient cycles, altered vegetation structure and fire regimes that in turn supported other prairie species. They are considered ‘ecosystem engineers’,” Shamon told EcoWatch.

“Today, most bison are no longer free roaming and are kept in production or conservation herds. However, they can still have an impact on the landscape. Studies show that under some management schemes, bison can have positive impacts on riparian vegetation restoration, and create heterogenous grasslands that can support many grassland specialists,” Shamon said.

Grasses are shorter where bison commonly graze, and prairie dogs dine on these shorter grasses and dig their burrows there, World Wildlife Fund reported. When bison make their way through the deep snow of a Great Plains winter, the paths they forge become “highways” for elk and pronghorn antelope, among other inhabitants who stick around through the winter months. As they dig through the snow, bison also make the hidden prairie grass available for animals who wouldn’t otherwise be able to access it.

“Prairie species evolved alongside bison, an iconic animal central to Plains Indian culture and communities for centuries,” said Shamon, as reported by South Dakota State University. “Against the backdrop of a changing climate, continued and new research is needed to develop bison restoration and land management strategies that maximize biodiversity and address the complex socio-economic and ecological needs of Native Nations.”

For thousands of years, Great Plains Tribes used every part of the bison — including the hides, bones and horns — for food and to make clothing, shelter, tools and musical instruments, and for other specialized uses.

“Buffalo are central to our community,” said study co-author and faculty member at the Aaniiih Nakoda College Daniel Kinsey, as South Dakota State University reported. “Fort Belknap reintroduced buffalo in the late 1970s, and we are fortunate to have such a successful program that is a product of hard-working people. It is my duty to connect our students, the younger generation, to the buffalo and the ecosystem and to work with students to incorporate our traditional knowledge into the present research. We recently established a new ʔíítaanɔ́ɔ́nʔí/Tatag ́a (bison in Aaniiih and Nakoda languages respectively) Research and Education Center for this purpose.”

Bison are an extremely adaptable species able to adjust to high temperatures and lack of water. Despite their size, bison’s needs are not as great as those of cows when it comes to taking refuge in the shade and seeking water; thus, where bison graze, grassland streams are not overrun with sediment.

“Bison are adapted to the climate of the Great Plains,” Shamon told EcoWatch. “Their physiology is what makes them tolerant to extreme weather.”

Compared to the rest of the country, the Northern Great Plains is becoming disproportionately warm and dry due to climate change, reported South Dakota State University. This will put the region’s agricultural system and the prairie ecosystem at risk as the climate crisis continues. Impoverished prairie communities that depend on the environment for their livelihoods will face a greater possibility of hardship.

“What we provide in this research article are successful solutions that are implemented on Indigenous lands. Many of those solutions may be applicable on other properties and some may not. The key is maintaining a high level of diversity and innovation to enhance sustainable solutions to climate change impacts,” said director of research for the Center of Excellence for Bison Studies at South Dakota State University Jeff Martin, as South Dakota State University reported.

The quality of the land on Native American reservations is often less than optimal and poverty and food insecurity disproportionately affect Tribal communities.

“In rural Native American communities, poverty is two to three times higher than in white rural communities, and, despite much of the grasslands being used for agriculture, Native Americans are twice as likely to be food insecure than white people and are 25% more likely to remain food insecure in the future,” reported South Dakota State University.

Restoration of bison herds on the Tribal lands of the Great Plains strongly correlates with the establishment of food sovereignty for the Plains Indians. However, the numbers of bison that would be needed to attain both restoration of herds and food sovereignty for Tribes are yet to be achieved, South Dakota State University reported.

“A reintroduction plan entails a feasibility assessment. There are certain criteria that need to be met in terms of habitat requirements, population genetic viability, social tolerance, and funding. Every reintroduction is unique and needs to be tailored to a specific community and place,” Shamon told EcoWatch.

According to South Dakota State University, theories derived from both commercial and conservation bison herds may need to be used for the successful reintroduction of bison on Tribal lands.

“Future bison reintroduction success requires merging the concepts of conservation and commercial herds or the growth of both herds until production meets local community food demands and conservation meets ecosystem service needs,” reported South Dakota State University.

The study recommended that management strategies for the reintroduction of bison on Tribal lands include “Indigenous and cultural knowledge” and be in keeping with the preservation of the bison’s “wild nature” for commercial and conservation herds. It also recommended monitoring how the reintroduction of bison affects an area’s biodiversity based on agreed upon monitoring and assessment standards.

“We are renewing our relationship with the buffalo as our relative, they are central to our lives,” said study co-author and member of the Pt’e stakeholder group, Fort Peck Indian Reservation, Roxann Smith, as South Dakota State University reported. “Together, our community is reclaiming our traditional ways and piecing our ecosystem together again as we heal together.”