Can Buffalo Shape the Prairie?
By Ross Martin
Buffalo Educator and Graduate Student, Yale School of the Environment
There’s a bull buffalo rolling on the ground. Hooves point skyward as the bull’s body moves—rocking, kicking, and sliding on a carefully chosen patch of earth. Dust hangs in the hot summer air. Other buffalo look on at the commotion, then return to grazing. A calf imitates the bull, playfully rolling under mom’s legs. What are these buffalo doing?
This is a classic summer scene where buffalo roam. Peculiar, dirt seeking behavior like this is called wallowing. Wallowing serves a variety of purposes for buffalo. The movement jostles off insects, the dirt coating provides protection from the sun, and the wallow they create becomes a social gathering place.
The bull buffalo gets up and wanders off. A yearling cow takes his place, and she is joined by another. Every new buffalo that uses the wallow deepens the depression and widens the circle. They’ll share this wallow until they migrate for fresh grass. The grass in this pasture will grow back, and the buffalo chips left by the herd will feed the soil and disappear. In a few months, most traces of this herd will be indiscernible on the landscape. But the buffalo wallow persists for years—decades even.
What seems like an unremarkable patch of earth—the wallow—plays an important role in prairie ecosystems. Wallowing creates a disturbance in the landscape, and that disturbance provides an opportunity for the web of life to work its magic. The collective weight of dozens of buffalo compacts the soil under a wallow. Water drains much more slowly from these places compared to the surrounding prairie. When the rains come, a wallow transforms into a temporary pool. These pools are oases in the arid expanse of the Great Plains. Insects thrive in and around the shallow water. Tadpoles eat those insects and grow into frogs. Foxes, coyotes and eagles eat the frogs. This circle continues, a legacy of the long gone buffalo herd.
The Great Plains were covered with wallows when there were millions of buffalo on the landscape. But with the buffalo gone, the wallows disappeared too. The depressions were filled in or smoothed over by plows. Cattle couldn’t replace buffalo– they don’t know how to wallow.
Buffalo herds have great power and impact on grasslands. Researchers call them “ecosystem engineers,” species capable of altering landscapes to promote resiliency, abundance, and biodiversity. Wallowing is one of the many ways buffalo support the other beings around them. Returning buffalo bring life with them for the frogs, insects, and people alike.