Blacktail Prairie Dog - Cynomys ludovicianus
Wind Cave National Park is really two parks in one. The surface is 28,000 acres of a complex mix of prairie grasses and ponderosa pine forest ecosystems. Seventy-five percent of the Park is open grassland, and living in that ecosystem is a large variety of mammals.
One of the more interesting sociable wild animals of the grasslands is the prairie dog, a rodent that belongs to the squirrel family. The name "prairie dog" came from their bark-like call, not from their appearance. They were called "petit chien" or little dog, by early French explorers and were scientifically described in the journals of Lewis and Clark.
The park has only one species of prairie dog, the blacktail prairie dog, named for the black tip of its tail. Blacktail prairie dogs have small ears, short tails, and muscular legs. Their fur is buff-colored and often blends with the earth in which they dig their burrows.
Prairie dogs rely on keen hearing, excellent eyesight and a communal warning system for protection against predators. They are social animals and the areas they inhabit are known as towns or colonies. Town is a good term because, in a way, their towns are much like ours. A dog town may vary in size from an acre to several hundred acres. In the 1800's, dog towns were described as stretching for miles; some extremely large towns are still found in South Dakota.
A typical prairie dog town consists of groups of prairie dogs that occupy and protect small areas within the town. These groups of prairie dogs are known as coteries, which may be compared to "neighborhoods" of human towns. Individual prairie dogs stay in their own neighborhoods. A typical coterie consists of one adult male, three or four adults females, and their young up to one year of age. The residents of each coterie protect their territory from intruders, including prairie dogs from other coteries within the town.
NPS Photo by Tom Bean
Members of the coterie cooperate with one another. Competition for food and shelter is uncommon within the coteries, and all members occupy a nearly equal social position. Members of the coterie recognize each other with a "kiss." They may also be seen grooming each other, cooperating in the construction of a burrow, aiding each other in defense of the territory, eating together, playing with one another, or standing side by side on a mound of earth.
Communication between the members of a town is very important and highly specialized. As many as ten different calls have been described, including sounds for warning, defense, territoriality, fear, or fighting. A warning cry from one prairie dog sends all within earshot hustling for their burrows.
NPS Photo by Tom Bean
Prairie dog burrows have not been studied intensively, but some general features are known. Depth of the burrow system is often governed by the local soils. In deep soil, the burrows may extend downward for ten or more feet, averaging 24 feet of tunnel per entrance. The prairie dogs pack a conical mound of soil around the entrance of the main burrow to serve as a lookout post and as protection against flooding. The entrance tunnel section extends steeply downward for several feet with the next tunnel section being gently inclined, descending down to the nest. The nest chamber is usually lined with grasses. Some tunnels then return to the surface, often with a depressed, crater-like opening marking their terminus. Several burrows may be connected underground. Tunnel plugs are common, but may be quickly re-excavated in emergencies.
NPS Photo by Allan Lovaas
Prairie dogs only give birth to one litter per year. The breeding season is mid-March to mid-April, with the young being born 4 to 5 weeks later. The size of the litter varies from 2 to 8 young, which are nursed by the mother for about 6 weeks. During May and the early part of June, the young begin to emerge from their burrows for the first time. At this time, yearlings (young from the previous year) and some adults may relocate, leaving the young pups to feel secure both socially and environmentally in the old burrow. When prairie dogs relocate, they take over abandoned holes or dig new holes at the edge of the town. A few may travel miles in search of new areas, but once away form the communal warning system, most are easy prey for predators.
NPS Photo by P.T. Bromley
Blacktail prairie dogs have incomplete hibernation, their activity and appetite are decreased during the winter. They may sleep for many days at a time, but the town is usually active during the milder days of the winter.
Common predators of the prairie dog include coyotes, bobcats, eagles, hawks, badgers, and weasels. One member of the weasel family, the black-footed ferret, deserves special mention. They are perhaps the rarest mammals in North America, depending primarily upon prairie dogs for food. Widespread poisoning of prairie dog towns endangered the existence of this interesting mammal.
Other animals may also be found in prairie dog towns. Snakes, including rattlesnakes, are fond of using abandoned burrows as homes, as are burrowing owls, birds with long legs and short tails. The owls can sometimes be seen standing on a mound in the midst of a prairie dog colony, creating little or no disturbance among the other inhabitants of the town.
For more information about Wind Cave National Park's prairie dog management plan click on management plan.