National Bison Day

Every year, on the first Saturday of November, we recognize National Bison Day and celebrate the ecological, cultural, and economic contributions of the United States’ national mammal. Although they were once found throughout Illinois and much of North America, bison were nearly driven to extinction in the 19th century as a result of westward expansion. Fortunately, thanks to the efforts of Native Americans, private individuals, and the U.S. Department of the Interior, the bison became one of the United States’ first successful conservation stories. The Nature Conservancy, Nachusa Grasslands, Midewin National Tallgrass Prairie, and Fermilab have all reintroduced bison to prairies in Illinois. According to the Nature Conservancy, there are currently 350,000 bison across the U.S., about 1% of their previous population; some on public lands, most in private herds.

The terms “buffalo” and “bison” are often used interchangeably, but they actually refer to two very different species! True buffalo are found in Africa and Asia, while bison are found in North America and Europe. Although they both belong to the family Bovidae (which also includes domestic cows, goats, and antelope), they aren’t closely related.

Adult male bison, known as bulls, can weigh up to 2,000 pounds (that’s one ton)! This enormous weight, and their eating behavior, actually benefit prairie ecosystems. They’re grazers, meaning that they primarily feed on grasses and sedges. This helps keep these plants pruned and allows other plants space to grow. Their hooves also help aerate the soil. When they roll around on the ground, they create wallows. Wallows are depressions that form in the earth which then create shallow pools of water when filled with rain. These wallows benefit birds, insects, and plants, and are uniquely created by bison alone!