Bison bison, commonly known as the American bison, is a large mammal native to North America. It is characterized by its massive head, humped shoulders, and thick fur, which can vary in color from dark brown to light tan. Bison are herbivores, primarily grazing on grasses and other vegetation in plains and prairies. These animals play a crucial role in their ecosystem by helping to maintain grassland health through their grazing habits. Once nearly extinct due to overhunting and habitat loss, conservation efforts have helped increase their populations, allowing them to roam in protected areas like national parks and reserves.