Black-tailed prairie dog (Cynomys ludovicianus)
|Also known as:||Arizona black-tailed prairie dog|
|Synonyms:||Cynomys ludovicianus arizonensis|
|Size||Male length: 358 – 429 mm (2)|
Female length: 340 – 400 mm (2)
Male weight: 575 – 1,490 g (2)
Female weight: 765 – 1,030 g (2)
Classified as Least Concern (LC) on the IUCN Red List (1).
Named for their dog-like yip, prairie dogs are in fact rather large, stout, ground-dwelling squirrels (3) (4). The black-tailed prairie dog is generally tan to pinkish-brown above and whitish to buff coloured below, and is named for the distinctive and diagnostic black tip to its short tail (4). Coat colour varies slightly with the seasons, with body hair being tipped black in winter but white in summer (5). The head is round with large black eyes and tiny round ears (3).
Found from extreme south-central Canada, through the United States, and into north-eastern Mexico (1) (6).
The black-tailed prairie dog lives in burrows in dry, short-grass prairies (1).
Black-tailed prairie dogs exhibit a high degree of social organisation, living in enormous colonies known as ‘towns’ containing from hundreds to millions of individuals (1) (7). Each colony shares an elaborate network of burrows for shelter and protection against predators, often covering areas of 100 hectares or more (1), with the largest ever recorded colony covering 65,000 square kilometres and containing an estimated 400 million animals (1) (7)! Colonies are subdivided into ‘wards’, and then into smaller family units called ‘coteries’, populated by a group of closely related females, one or two territorial males, and any offspring under two years of age (7) (8). Members of a coterie share food supplies outside of the breeding season and cooperate to aggressively defend their territory from neighbours (2) (7). However, while males respond strongly to intrusion by other males they seem oblivious to invading females; females, by contrast, show the most hostility toward invading females. During the breeding season, females aggressively defend their natal burrow against other females and, given the opportunity, will even raid the burrows of other females and kill their pups (7).
Mating is polygynous, with the usually single male mating with multiple females within his coterie. In cases when there is more than one resident male, usually brothers, females will mate with both. Reproduction occurs once per year in spring, although the timing varies with latitude, and females are typically sexually receptive for only one day of the year (7). A litter of one to eight pups is born after a gestation of 33 to 38 days. Young are born blind, naked and mostly helpless (7), and do not emerge from the burrow until around six weeks of age, and are weaned shortly after that (4). Interestingly, after emerging from the burrow, but prior to the end of lactation, pups may nurse from females other than their own mother, an example of ‘cooperative breeding’ (7). Females remain in their natal coterie for life, while males disperse before their first breeding season (7) (8). Likewise, adult males rarely remain within the same coterie for more than two breeding seasons, probably to reduce the possibility that they will mate with their own female offspring. Females can live up to eight years of age, whereas males tend not to live longer than five years in the wild (7).
The black-tailed prairie dog is diurnal and active throughout the year (7). Unlike many other species of prairie dog, these animals do not hibernate, although when the winter weather is extremely cold or snowy they may spend extended periods of time underground (2). Most activity is conducted during the cool hours of the day, when individuals engage in social activities, such as grooming each other, as well as feeding on grasses, herbs and the occasional invertebrate (7), while midday hours are usually spent sleeping below ground (4). Most prairie dogs forage close to their burrows when possible, moving into distant foraging areas only when forced to do so by local shortages of green shoots (7). While prairie dogs are out foraging, a sentry perches on the volcano-like ring that surrounds the burrow and watches for predators. Should a predator or any other danger be spotted, the sentry will bark out a warning, causing the community to dive into their burrows and wait for the ‘all clear’ call before venturing out again (7).
Prairie dogs have suffered from habitat loss and persecution as ranching and farming has expanded during the past 50 years or more (1) (4). As agriculture and livestock ranching claimed habitat previously used by these rodents, the prairie dogs became vilified by farmers and the target of poisoning campaigns (1). Prairie dogs are widely considered a pest and exterminated through poisoning and shooting for destroying cultivated crops (8). They are also reported to compete with cattle and sheep for grasses, although there is little evidence for this, and their burrow systems are alleged to present hazards to cattle and horses, making broken legs a threat, although this is also rare (9). As a result, the former range and numbers of the black-tailed prairie dog have been dramatically reduced, and the considerable reduction in population numbers has also seriously threatened, amongst others, the black-footed ferret (classified as Extinct in the Wild), for which they were virtually sole prey (5). Nevertheless, many black-tailed prairie dog colonies persist in protected areas (9), and this remains the most common and widespread of the five prairie dog species (8).
Still widespread, relatively common, and existing in a number of protected areas, the black-tailed prairie dog is not considered to be under any serious threat of extinction in the foreseeable future, and conservation measures are therefore limited (7). The Prairie Dog Coalition has been established to protect the animals and restore prairie dog ecosystems, as well as aiming to raise public awareness of the plight they face at the hands of agricultural expansion and misinformed farmers (10).
For more information on this and other prairie dogs, including their conservation, see:
- The Prairie Dog Coalition:
- Hoogland, J. (1995) The Black-tailed Prairie Dog: Social Life of a Burrowing Mammal. University of Chicago Press, Chicago.
Authenticated (21/02/08) by Dr. Debra Shier, Applied Animal Ecology, Conservation and Research for Endangered Species, Zoological Society of San Diego.
- Colony: a group of organisms living together. Individuals in a colony are not physiologically connected and may not be related, such as a colony of birds.
- Diurnal: active during the day.
- Gestation: the state of being pregnant; the period from conception to birth.
- Hibernate: hibernation is a winter survival strategy characteristic of some mammals in which an animal’s metabolic rate slows down and a state of deep sleep is attained. Whilst hibernating, animals survive on stored reserves of fat that they have accumulated in summer.
- Invertebrate: animal with no backbone.
- Polygyny: in animals, a pattern of mating in which a male has more than one female partner.
- Prairies: Extensive areas of flat or rolling, predominantly treeless grassland, especially the large tract or plain of central North America.
- Territory: area occupied and defended by an animal, a pair of animals or a colony.
IUCN Red List (July, 2014)