(StatePoint) The plains bison (or buffalo) is America’s National Mammal. When you think of this majestic species, several associations may come to mind: their long history with Native people and the animal’s near extinction, their impressive size, and their place within our national parks.
“Bison are the great shapers of the North American grasslands.” says Dennis Jorgensen, bison program manager at World Wildlife Fund. “As both an ecological and cultural keystone, bison are the living heartbeat of the prairie.”
Ground Breakers and Home Makers
Grasslands are often subjected to frigid winters, wet springs and hot, dry summers. When precipitation arrives, bison help prairies absorb water through “hoof action.” Adult males can weigh more than a ton. As they walk across dry prairies, their hooves punch holes in the soil, allowing water to seep into the earth, rather than washing away.
If you’ve ever visited Yellowstone National Park, you might have seen bison demonstrating another interesting behavior called wallowing. Bison wallow (roll around) to remove parasites or scratch an itch. Many reuse the same wallowing spots, creating crater-like impressions across the landscape. When it rains, wallows fill with water, which slowly seeps into the soil. In areas where hundreds of bison roam, this network of basins creates a mineral-rich wetland habitat where amphibians, like tiger salamanders, lay eggs and unique plant communities thrive.
All this rolling around and scratching also help bison shed their warm, insulative fur, which many species of bird, from red-winged black birds to eastern kingbirds, line their nests with to keep their young warm.
“Bison epitomize the interconnectedness that can exist between a landscape and species. These large grazers are intertwined with so many grassland plants, animals and people,” says Noelle Guernsey, senior specialist, Bison Restoration, World Wildlife Fund.
Road Crew
As bison graze, they turn grass into manure. This nutrient recycling process is critical for producing soil, fertilizing plants, and providing food, shelter and protection for other species. Dung beetles roll, tunnel and bury their way through it. Predatory beetles and garter snakes take shelter beneath droppings, awaiting flies and other prey. And even one species of mason bee is thought to nest in bison dung. Burrowing owls have also learned that lining their nest tunnels with bison dung is a great way to attract dung-beetles: one of their favorite snacks.
During winter, bison play another vital role. Using their massive heads, horns and shoulder muscles, they clear away snow to reach tender plants hidden beneath. Smaller plant eaters, like pronghorn and deer, use these bison-cleared trails like highways to pass through deep snow that would otherwise be unpassable. These paths can be critical to their survival, since without access to new pastures and forage they might otherwise starve.
“In many ways, the plains bison is symbolic of the values the United States was founded upon. These animals are resilient, community-minded, determined, and tied to the fate of grasslands, which have provided for humans for millennia,” says Clay Bolt, Great Plains communications, World Wildlife Fund.
World Wildlife Fund’s “Stories of Hope and Wonder” is an ongoing series that connects people to the wonder of nature and offers hope for a future benefiting both people and wildlife. Each month, Stories of Hope and Wonder will feature a different species overcoming some of nature’s toughest obstacles to ensure their survival. To read past editions, visit www.worldwildlife.org/hopeandwonder.
Photo 1 Credit: (c) Tailyr Irvine / WWF-US
Photo 2 Credit: (c) WWF-US / Clay Bolt
