Grasslands National Park of Canada
The Black-tailed Prairie Dog
Louisiana dog-mouse, the barking squirrel, le petit chien and 'playful one' are all descriptive names for the same animal, Chynomys ludovicianus: the Black-tailed Prairie Dog. This playful and social little animal is a favourite among visitors to Grasslands National Park of Canada.
Life History and Biology
Black tailed prairie dogs are large; up to 40cm (16") long and weigh as much as 0.5 - 1.5kg (1-3 lbs). They are easily distinguishable from the Richardson's Ground Squirrel, or common gopher. They are pale cinnamon buff in colour with a white underside and a black tipped tail.
Black-tailed prairie dogs are a daytime species. They usually spend the first two hours after sunrise foraging and eating, and the remainder of the day grooming, dustbathing, stretching, socializing and repairing their burrows. Prairie dogs feed primarily on vegetation, mainly grasses and roots, though occasionally they will feed on insects.
Prairie dogs molt twice a year. Their summer coat is light, with almost no underfur. Their winter coat has a thick, warm underfur. Prairie dogs do not undergo true hibernation. Instead, the northern prairie dogs will regulate their body temperature during the winter to control energy. This is called facultative torpor. They do not store food in preparation for the long winter but will live off the fat reserves stored in their body. On the occasional sunny winter day, they may venture out to forage for roots and grass.
Squatting back on his haunches, looking relaxed very well-fed, this chubby, black-tailed prairie dog awaits his next photo opportunity.© Parks Canada / Wayne Lynch, 1981
Mating takes place underground in early spring (March - mid April). This is the only time of year when the prairie dog becomes aggressive. The dark red, wrinkled, hairless, blind young are born 35 days later. Besides being fairly unattractive, they are also very vulnerable. They remain in their burrow for five to six weeks and appear above ground in June - July. After two to three weeks above ground, the parents abandon their burrow to their young, while they establish a new burrow.
Black-tailed prairie dogs are very social animals, a feature which makes them a delight to watch. The dog colony is divided into a variety of social units. The borders of these social units are defined by natural features such as tall grass, rocky ground, creeks or brush. Each social unit is called a coterie and is comprised of one male, 3-4 females and their young up to one year of age. Members of the coterie identify each other by muzzling or 'kissing'. They also groom and play as a means of communicating. Prairie dogs have a varied vocabulary of barks and calls.
As a prairie dog colony grows in size, it becomes necessary for some prairie dogs to move out and establish a new town. When the adults move out, they may travel as far as 10km or more and even swim across rivers and lakes. Usually, members of the same coterie travel out to establish a new colony.
When a new colony is established, the prairie dogs make a home for themselves and a home for a whole host of other animals. Burrowing owls live in the burrows of the prairie dogs; rattlesnakes seek the protective shelter of the burrows and eat the young prairie dogs; short- horned lizards and black widow spiders also find food and refuge in the colony. Prairie dogs are preyed upon by badgers, eagles, hawks, coyotes, and foxes. Prairie dogs form a critical link in a complex prairie food web.
Hundreds of mounds the size of mole hills are found in a single prairie dog colony. Their shape is mirrored in the rolling hills seen behind.© Parks Canada / Wayne Lynch, 1981
The Critical Link
Prairie dogs are seen as competing with cattle for food and being a danger to livestock. They have been poisoned, trapped, shot, flooded and dynamited out of their homes. With them went the owls, ferrets, snakes, foxes and badgers. The delicate balance of nature had once again been disrupted.
Aside from its curious social habits and behaviour, the black-tailed prairie dog is a key component of the grasslands ecosystem. In and around Grasslands National Park of Canada is the only place in Canada where they exist in the wild.
It was not until 1927 that the first prairie dog towns were discovered in Canada. The first colony was found six miles north of the village of Val Marie. Presently there are some 25 colonies in and around the park ranging from 0.55 ha to 171.56 ha in size. It is roughly estimated that the colonies may contain as many as 17,000 - 23, 000 animals. Eventually, the colonies may be large enough and close enough to each other to support a few families of reintroduced black-footed ferrets.
The black-tailed prairie dog is one of those critical species that acts as a link between a myriad of other species. Its very existence serves to demonstrate the complexity of natural systems and the interconnections among all things. The history of the prairie dog is also a lesson in stewardship: we have learned that by affecting the life of any one creature, we inevitably impact the lives of many others.
The health and success of the black-tailed prairie dog means the survival of the coyote, the fox, and the badger. It means the potential for success of the swift fox, the ferruginous hawk and the burrowing owl. It also means a chance at life for the short-horned lizard, the prairie rattlesnake and the black-footed ferret. Finally, it means peace of mind for all of us stewards of the earth; and it means the opportunity to continue to observe this fascinating and amiable little rodent.
The black-tailed prairie dog is a member of the squirrel family. Large eye sockets give it the capacity to have a large range of vision, necessary for spotting danger. It is a primitive rodent, its large teeth are well suited to its diet of grass, roots and insects.