When most people think of wildlife, it's mammals that come to mind-and Badlands is a great place for seeing mammals. From tiny shrews to 2,000-pound bison, 39 species of mammals may be found on the Badlands prairie.
Very hot summers, bitterly cold winters, and high winds at any time of year make surviving on the northern prairie a challenge. Most small mammals make use of burrows or other hiding places where they can find protection. Prairie dogs, for example, excavate burrows in expansive areas known as towns. The burrows provide prairie dogs with shelter from both the weather and predators, and many other species can take shelter in the prairie dogs' tunnels too. As a result, prairie dogs are a keystone species; that is, their presence is critical to the overall ecological community of the mixed-grass prairie. Badgers, bobcats, coyotes, swift foxes, and black-footed ferrets are some of the predators that are often found in close association with prairie dogs. Getting a glimpse of one of these predators is a special treat for park visitors.
Large ungulates, or hoofed mammals, include bison, mule deer, white-tailed deer, Rocky Mountain bighorn sheep, and pronghorn. The ungulates are large enough that their body size affords them some protection against cold; bigger animals have less surface area exposed in relation to their volume, so they lose heat more slowly than a smaller animal would. Their size also makes them easier to spot, and these animals are some of the most exciting for park visitors to see.