Once upon a time, there were tens of millions of bison on the North American continent. Today, there are somewhere between 400,000 and 500,000. Most are in commercial herds, with a relative few in private herds and on public lands.

Should there be more bison on the continent? There potentially is space for them on places like the 550,000-acre Thunder Basin National Grassland in Wyoming, the nearly 600,000-acre Buffalo Gap National Grassland in South Dakota, and the roughly 440,000-acre Comanche National Grassland in Colorado, just to name three locations.

And a new study out this past week explains why bison are more beneficial for grasslands than traditional livestock, and the benefits increase as herd size does. To understand what's going on, we're joined today by Professor William Hamilton from Washington and Lee University in Virginia, one of the study's co-authors.