American Prairie Reserve’s mission to create a reserve of more than three million acres represents one of the largest conservation projects in the United States today. The size of the project is hard to grasp – even a small piece of the 274,000 acres that currently comprise the Reserve seems like an endless “sea of grass” to both first-time and seasoned visitors. However, after ten weeks of research on historical wildlife populations of Montana’s glaciated plains, I have become increasingly convinced that APR’s vision is necessary. If we want to understand the behavior and ecology of grassland species, we need to think big.
America’s iconic species – bison, pronghorn, elk, wolves, grizzly bears – evolved over tens of thousands of years on a wide-open continent. Over this long period of time, these species became well adapted to environmental “stochasticity,” the highly dynamic and unpredictable nature of their habitat. In fact, the prairie is one of the most dynamic ecosystems in the world.
Settlers came to Montana in the early 20th century after being told that if they turned the soil they could transform the rugged landscape and cultivate a fertile Eden. A few years of unusually (and well-timed) wet conditions in the 1910′s bolstered this belief, but a severe drought in the 1920′s caused devastation for most agricultural producers. Unlike its settlers, though, the region’s wildlife had evolved several adaptations to deal with these rapid and extreme fluctuations. It turns out that the key to persistence in a highly stochastic environment is to employ a range of survival techniques.
On a wide-open continent, ungulates like elk, deer and pronghorn thrived in many different habitats and were able to chose from a toolkit of survival strategies grounded in their history and experience on the land. If conditions were optimal, herds would be inclined to stay put, but in periods of high environmental variance, they would have had to choose a new strategy. For instance, when temperatures dropped abnormally low, ungulates fled the prairie and sought thermal refuge in the Missouri River Breaks or the Rocky Mountains.
Through my research, I also discovered the debate over whether bison were historically a migratory or a nomadic species. Did they follow specific migratory patterns, or did they move in a sporadic, localized manner related to the availability of food? We’re not sure, but the truth is probably somewhere in the middle. Regardless, much of the migratory behavior that we observe in terrestrial species today is shaped by human intervention. We have severely restricted the habitats of most wildlife species, and climate change threatens what marginal areas remain.
Recent studies predict that changes in climate, such as increases in severe weather events and changes in precipitation levels, will affect grassland ecosystems, from native plant and weed distribution to altered fire regimes. Conservation planners will have to react to these to the best of their ability within the limits of science, funds, and space.
For the ungulate species that American Prairie Reserve (APR) is trying to recover, bigger is better. A large reserve would allow wildlife to utilize more of the strategies in their survival toolbox. It may also be able to buffer the adverse effects of climate change by encompassing more habitat niches and providing more space for wildlife to disperse while still remaining within reserve boundaries. Furthermore, a large area has the capacity to support higher numbers of wildlife, which greatly reduces the risk of a population extinction event.
American Prairie Reserve recently celebrated the acquisition of a 150,000-acre property that more than doubled the size of previous habitat and added 16 miles of shared border with the 1.1 million-acre Charles M. Russell National Wildlife Refuge. Even though the goal of APR seems very ambitious at times, we must remember that wildlife persisted on a much larger landscape for thousands of years before Lewis and Clark ever walked on this land.
Thus, it is a mistake to conceptually box these species into a specific habitat-type or set of behaviors. As Lewis put it, the historical American West contained “immence herds of Buffaloe, Elk, deer and antelopes feeding in one common and boundless pasture.” While we will never be able to recapture the full picture of historical wildlife on the frontier, American Prairie Reserve can reestablish a pretty big chunk of that natural legacy.
American Prairie Reserve intern Michelle Berry is a Master’s student in environmental studies at Stanford. She has been tasked with examining historical works of literature and other primary sources to establish wildlife population estimates in the Reserve region of northeastern Montana. Her 10-week internship was made possible by the Bill Lane Center for the American West.