Above the shortgrass prairie of Theodore Roosevelt National Park, the colorful strata of North Dakota's badlands resemble slices of a geological wedding cake. On a barren patch of earth, you're likely to spy a few small rodents the color of coffee with a liberal splash of milk--their large dark eyes, small ears, and pointed sloping noses set on oval heads. Some sit upright near earthen mounds, while others graze on all fours, clutching grasses between their forepaws. At the approach of a human, they squat in their burrows, their tails up and twitching. Moments later, they emit a series of high-pitched barks and disappear into their dark burrows. They may resemble barking squirrels, but they're actually black-tailed prairie dogs.
Prairie dogs were named by early Western explorers, who found their bark similar to that of a domesticated dog. The black-tailed variety ranges from the Missouri River west to the Rocky Mountains and from southern Canada to northern Mexico. Historic accounts vary, but the U.S. Fish and Wildlife Service estimates that prairie dogs once covered 100 million acres through the United States (roughly the size of California). During the 20th century, the species was eradicated from much of that range by shooting and poisoning; more recently, sylvatic plague has decimated their numbers. Today, black-tailed prairie dog colonies cover less than 2 million acres. Despite this precipitous decline, the black-tailed prairie dog was removed from consideration as an endangered species in 2004.
Theodore Roosevelt National Park has approximately 1,500 acres of black-tailed prairie dog colonies and is located on the eastern edge of their range. Contemporary prairie dog colonies or towns range from several hundred animals to several thousand--a communal lifestyle that serves the species well.
"The big advantage of living in a group is that you're not the only one looking over your shoulder," says Mike Oehler, a wildlife biologist at Theodore Roosevelt National Park. "Your chances of being singled out in a large group are significantly smaller."
And when you are an important food source for predators such as the golden eagle, ferruginous hawk, coyote, fox, badger, and bobcat, disappearing into a crowd is a good strategy. "The prairie dog is a linchpin species in the food chain out here," explains John O"Connor, a seasonal park ranger who leads hikes to a prairie dog town in the park"s North Unit. The endangered black-footed ferret, another predator, hasn"t yet been reintroduced because prairie dog colonies within the park are too small and far apart.
But the black-tailed prairie dog is more than just an entrée on the menu of the western shortgrass prairie. "Prairie dogs create the edge effect," says Oehler. "They create a mosaic of habitat." Burrowing owls, rattlesnakes, and black widow spiders use prairie dog burrows as homes. During the springtime, sharp-tailed grouse in the colonies strut, ruffle their feathers, and inflate air sacs to impress potential mates. Pronghorn antelope are drawn to nutritious forbs--nonwoody, broad-leafed plants that grow in prairie dog towns.
The prairie dog is at the center of several symbiotic relationships. Bison breed in prairie dog towns and use patches of open dirt for wallowing--behavior that removes parasites from their shaggy coats. They also aerate the soil with their hooves while grazing--behavior that eventually replaces native grasses with low-lying forbs and allows prairie dogs to see predators from a distance. Those varied plant communities then attract different species of animals. "Think of the high-nitrogen forbs as filet mignon and think of the grass as hotdogs," says Oehler. "Some species need quality and some species need quantity."
Unfortunately, not everyone is thrilled with this emerging biodiversity. Forbs that grow on prairie dog colonies aren"t ideal for cattle, which require large volumes of grass. Ranchers and farmers outside the park typically consider the black-tailed prairie dog a pest that denudes the land, reduces forage, and competes with their herds. That makes the species' future on private land uncertain. But "painting all landowners with a broad brush isn"t fair," says Oehler, who knows that some landowners don"t mind the presence of prairie dogs.
Back at the North Unit visitor's center, Katherine Stanton, a seasonal park ranger, says that one of the National Park Service's goals in Theodore Roosevelt National Park is "to preserve every type of wild animal." The park's management plan seeks to preserve the prairie dogs while allowing for natural processes. Although Oehler predicts that the black-tailed prairie dog will continue to be controversial outside the park, he is hopeful about their future on parkland. "Throughout the West, prairie dogs may continue to get persecuted," he says, "but on public lands, they can be saved."
