American Bison

The largest land mammal in North America, once numbering in the tens of millions across the continent's grasslands before nineteenth-century commercial hunting and a deliberate campaign to undermine Plains nations who depended on the herds reduced the wild population to only a few hundred animals by the 1880s. Yellowstone National Park sheltered one of the last wild herds through that collapse and remains the only place bison have lived continuously since prehistoric times without ever being fully extirpated and reintroduced. Bison graze in large mixed herds, wallow in dust and mud to coat themselves against insects and shed fur, and their grazing pattern shapes prairie plant diversity in ways ecologists consider close to the pattern the grassland evolved under, a role modern conservation herds are managed in part to restore.