Prairie dog

This article is about the animal. For other uses, see Prairie dog (disambiguation).

Prairie dogs Temporal range: Late Pliocene to Recent
Black-tailed prairie dogs
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Suborder:	Sciuromorpha
Family:	Sciuridae
Tribe:	Marmotini
Genus:	Cynomys Rafinesque, 1817
Species
Cynomys gunnisoni Cynomys leucurus Cynomys ludovicianus Cynomys mexicanus Cynomys parvidens

Prairie dogs (genus Cynomys) are burrowing rodents native to the grasslands of North America. There are five different species of prairie dogs: black-tailed, white-tailed, Gunnison's, Utah and Mexican prairie dogs. They are a type of ground squirrel, found in the United States, Canada and Mexico. In Mexico, prairie dogs are primarily found in the northern states which are the southern end of the great plains: northeastern Sonora, north and northeastern Chihuahua, northern Coahuila, northern Nuevo León, and northern Tamaulipas. In the U.S., they range primarily to the west of the Mississippi River, though they have also been introduced in a few eastern locales. They are herbivorous, and will eat all sorts of vegetables and fruits.

Etymology

Prairie dogs raise their heads from their burrows in response to disturbances

Prairie dogs are named for their habitat and warning call, which sounds similar to a dog's bark. The name was in use at least as early as 1774.^[1] The 1804 journals of the Lewis and Clark Expedition note that in September 1804, they "discovered a Village of an animal the French Call the Prairie Dog."^[2] Its genus, Cynomys, derives from the Greek for dog mouse.

In companies that use large numbers of cubicles in a common space, employees sometimes use the term prairie dogging to refer to the action of several people simultaneously looking over the walls of their cubicles in response to a noise or other distraction. This action is thought to resemble the startled response of a group of prairie dogs.^[3]

Classification and first identification

The Black-tailed Prairie Dog (Cynomys ludovicianus) was first described by Lewis and Clark in 1804 during the Lewis and Clark Expedition.^[2] Lewis described it in more detail in 1806, calling it the "barking squirrel."^[4]

• ORDER RODENTIA
• Suborder Sciuromorpha
  • FAMILY SCIURIDAE (Squirrels, chipmunks, marmots, and prairie dogs)
    • Subfamily Xerinae
      • Genus Cynomys
        • Gunnison's Prairie Dog, Cynomys gunnisonium nocterna
        • White-tailed Prairie Dog, Cynomys leudacurus
        • Black-tailed Prairie Dog, Cynomys ludovicianus
        • Mexican Prairie Dog, Cynomys mexican
        • Utah Prairie Dog, Cynomys pardos
      • About 14 other genera in subfamily

Physical description

Full view of prairie dog

On average, these stout-bodied rodents will grow to be between 30–40 centimetres (12–16 in) long, including the short tail and weigh between 0.5–1.5 kilograms (1–3 lb). There is sexual dimorphism in body mass in the prairie dog which varies between a 105-136% difference between the sexes.^[5] Among the species, black-tailed prairie dogs tend to be the least sexually dimorphic and white-tailed prairie dogs tend to be the most sexually dimorphic. Sexual dimorphism peaks during weaning when the females lose weight and the males start eating more and is at its lowest when the females are pregnant which is also when the males are tired from breeding.

Ecology and behavior

Diet

Prairie dogs are chiefly herbivorous, though they eat some insects. They feed primarily on grasses and, in the fall, broadleaf forbs. In the winter, lactating and pregnant females supplement their diet with snow for extra water.^[6] They also will eat roots, seeds, fruit and buds. Grasses of various species are eaten. Black-tailed prairie dogs in South Dakota eat western bluegrass, blue grama, buffalo grass, six weeks fescue, and tumblegrass,^[6] while Gunnison’s prairie dogs eat rabbit basin, tumbleweeds, dandelions, saltbush and cacti in addition to buffalo grass and blue grama.

Habitat and burrowing

Prairie dogs at a burrow entrance

Prairie dogs mainly live in altitudes ranging from 2,000-10,000ft above sea level.^[7] The areas in which they live can get as warm as 100 degrees in the summer and as cold as -35 degrees in the winter.^[7] As prairie dogs live in areas that are prone to environmental threats including hailstorms, blizzards, and floods as well as drought and prairie fires, burrows provide important protection for them. Prairie dog burrows can serve to control temperature as they are 5-10 degrees Celsius during the winter and 15-25 degrees Celsius in the summer. Prairie dog tunnel systems help channel rainwater into the water table to prevent runoff and erosion, and can also serve to change the composition of the soil in a region by reversing soil compaction that can be a result of cattle grazing.

Prairie dog burrows are 5-10m (16-33ft) long and 2-3m (6-10ft) below the ground.^[8] The entrance holes are generally 10-30cm (4-12in) in diameter.^[8] Prairie dog burrows can have 1-6 entrances. Sometimes the entrances are simply flat holes in the ground while other times they are surrounded by mounds of dirt that are either left as piles or packed down hard.^[8] Some mounds, known as dome craters, can be as high as 0.2-0.3 meters (8-12in) high. Other mounds, known as rim craters, can be as high as 1m.^[8] Dome craters and rim craters serve as observation posts which the animals use to watch out for predators. They also function to protect the burrows from flooding. It is also possible that the holes also provide ventilation as the air enters through the dome crater and leaves through the rim crater causing a breeze though the burrow.^[8] Prairie dog burrows contain chambers that provide certain functions. They have chamber for their young called nursery chambers; chamber for night-time and chambers for the winter. They also contain air chambers that may function to protect the burrow from flooding^[7] and a listening post for predators. When hiding from predators, prairie dogs use less deep chambers that are usually a meter below the surface.^[8] Nursery chambers tend to be deeper, being 60-76cm (2-2½ft) below the surface.^{[8][dubious – discuss]}

Social organization and spacing

Prairie dog family

Highly social, prairie dogs live in large colonies or "towns" – collections of prairie dog families that can span hundreds of acres. The prairie dog family groups are the most basic units of its society.^[8] Members of a family group inhabit the same territory.^[5] Family groups of black-tailed and Mexican prairie dogs are called "coteries" while "clans" are used to describe family groups of white-tailed, Gunnison’s and Utah prairie dogs.^[5] Although these two family groups are similar, coteries tend to be more closely knit than clans.^[9] Members of a family group interact through oral contact or "kissing" and groom one another.^[7][8] They do not perform these behaviors with prairie dogs from other family groups.^[8]

Prairie dogs showing affection

A prairie dog town may contain 15-26 family groups.^[8] There may also be sub-groups within a town called "wards" which are separated by a physical barrier. Family groups exist within these wards. Most prairie dog family groups are made up of one adult breeding male, two to three adult females and one to two male offspring and one to two female offspring. Females remain in their natal groups for life and are thus the source of stability in the groups.^[8] Males leave their natal groups when they mature to find another family group to defend and breed in. Some family groups contain more breeding females than one male can control as thus have more than one breeding adult male in them. Among these multiple male groups, some may contain males that have friendly relationships but the majority contain males that have largely antagonistic relationships. In the former, the males tend to be related while in the latter they tend to not to be related.^[8] There may be two to three groups of females controlled by one male.^[8] However among these female groups there are no friendly relations.^[8]

The average prairie dog territory takes up 0.05-1.01 hectares.^[8] Territories have well established borders that coincide with physical barriers like rocks and trees.^[8] The resident male of a territory defends it and agonistic behavior will occur between two males of different families defend their territories. These interactions may happen 20 times per day and last 5 minutes. When two prairie dogs encounter each other at the edges of their territories that will start staring, make bluff charges, flare their tails, chatter their teeth, and sniff each others perianal scent glands.^[8] When fighting, prairie dogs will bite, kick and ram each other.^[8] If their competitor is around their size or less, the females will participate in fighting. Otherwise, if a competitor is sighted, the females signal for the resident male.

Reproduction and parenting

Female with juvenile

Prairie dog copulation occurs in the burrows.^[10] This reduces the risk of it being interrupted by a competing male. They are also at less risk of predation. Behaviors that signal that a female is in estrous include underground consorting, self- licking of genitals, dust bathing and late entrances into the burrow at night.^[10] The licking of genitals may protect against sexually transmitted diseases and genital infections^[10] while dust bathing may protect against fleas and other parasites. Prairie dogs also have a mating call which consists of a set of 2-25 barks with a 3-15 second pause between each one.^[10] Female may try to increase their reproduction success by mating with males outside their family groups. When copulation is over the male is no longer interested in the female sexually but will prevent other males from mating with her.^[10] Males may prevent females from mating with other males by inserting copulatory plugs.^[10]

Juvenile prairie dogs

For black-tailed prairie dogs, the resident male of the family group fathers all the offspring.^[11] Multiple paternity in litters seems to be more common in Utah and Gunnison’s prairie dogs.^[9] Mother prairie dogs do most of the care for the young. In addition to nursing the young, the mother also defends the nursery chamber and collects grass for the nest. Males play their part by defending the territories and maintaining the burrows.^[8] The young spend their first six weeks below the ground being nursed.^[7] They are then weaned and begin to surface from the burrow. By five months they are fully grown.^[7] The subject of cooperate breeding in prairie dogs has been debated among biologists. Some argue that prairie dogs will defend and feed young that are not theirs^[12] and it seems young will sleep in nursery chamber with other mothers and since most nursing occurs at night, this may be a case of communal nursing.^[8] In the case of the latter, others suggest that communal nursing only occurs when mothers mistake someone else’s young for their own.

Infanticide is known to occur in prairie dogs. Males who take over a family group will kill the offspring of the previous male.^[8] This causes the mother to go into estrous sooner.^[8] However, most infanticide is done by close relatives.^[8] Lactating females will kill the offspring of a related female both to decrease competition for the female’s offspring and for increased foraging area due to a decrease in territorial defense by the victimized mother. Supporters of the theory that prairie dog are communal breeders state that another reason for this type of infanticide is so the female can get a possible helper. With their own offspring gone, the victimized mother may help raise the young of other females.

Anti-predator calls

Prairie dog calling

The prairie dog is well adapted to predators. Using its dichromatic color vision, it can detect predators from a far distance and then alert other prairie dogs to the danger with a special, high-pitched call. Constantine Slobodchikoff and others assert that prairie dogs use a sophisticated system of vocal communication to describe specific predators.^[13] According to them, prairie dog calls contain specific information as to what the predator is, how big it is and how fast it is approaching.^[13] These have been described as a form of grammar. According to Slobodchikoff, these calls, with their individuality in response to a specific predator imply that prairie dogs have highly developed cognitive abilities.^[13] He also writes that prairie dogs have calls for things that are not predators to them. This is cited as evidence that the animals have a very descriptive language and have calls for any potential threat.^[13]

There is debate over whether the alarm calling of prairie dogs is selfish or altruistic. It is possible that prairie dogs alarm others to the presence of a predator so they can protect themselves. However it is also possible that the calls are meant to cause confusion and panic in the groups and cause the others to be more conspicuous to the predator than the caller. Studies of black-tailed prairie dogs suggest that alarm calling is a form of kin selection as a prairie dog’s call alerts both offspring as well as non-descended kin like cousins, nephews and nieces.^[8] Prairie dogs with kin close by called more often than those that didn’t have kin nearby. In addition, the caller may be trying to make itself more noticeable to the predator.^[8] However, it seems that a predator has difficulty determining which prairie dog is making the call due to its "ventriloquial" nature.^[8] Also, it seems when a prairie dog makes a call, the others do not run into the burrows but stand on the mounds to see where the predator is, making themselves visible to the predator.^[8]

Conservation status

A prairie dog and his hole

Ecologists consider this rodent to be a keystone species. They are an important prey species, being the primary diet in prairie species such as the Black-footed Ferret, Swift Fox, Golden Eagle, American Badger, and Ferruginous Hawk. Other species, such as the Mountain Plover and the Burrowing Owl, also rely on prairie dog burrows for nesting areas. Even grazing species such as Plains Bison, Pronghorn, and Mule deer have shown a proclivity for grazing on the same land used by prairie dogs.^[14]

Nevertheless, prairie dogs are often identified as pests and exterminated from agricultural properties because they are capable of damaging crops, as they clear the immediate area around their burrows of most vegetation.^[15]

A Black-tailed Prairie Dog forages above ground for grasses and leaves

As a result, prairie dog habitat has been impacted by direct removal by ranchers and farmers as well as the more obvious encroachment of urban development which has greatly reduced their populations. The removal of prairie dogs "causes undesirable spread of brush" the costs of which to livestock range may outweigh the benefits of removal.^[16] The largest remaining community comprises Black-tailed Prairie Dogs.^{[citation needed]} In spite of human encroachment, prairie dogs have adapted, continuing to dig burrows in open areas of western cities.^{[citation needed]}

One common concern which led to the widespread extermination of prairie dog colonies was that their digging activities could injure horses^[17] by fracturing their limbs. However, according to writer Fred Durso, Jr. of E Magazine, "after years of asking ranchers this question, we have found not one example."^[18] Another concern is their susceptibility to bubonic plague.^[19]

In captivity

Prairie dogs are gaining popularity as zoo animals

South Central Wisconsin, USA

Until 2003, primarily black-tailed prairie dogs were collected from the wild for the exotic pet trade in Canada, the United States, Japan, and Europe. They were removed from their underground burrows each spring, as young pups, with a large vacuum device.^[20] They can be difficult to breed in captivity,^[21] but breed well in zoos. Removing them from the wild was a far more common method of supplying the market demand.^{[citation needed]}

They can be difficult pets to care for, requiring regular attention and a very specific diet of grasses and hay. Each year they go into a period called rut that can last for several months, in which their personalities can drastically change, often becoming defensive or even aggressive. Despite their needs, prairie dogs are very social animals and come to almost seem like they treat humans as members of their colony, answering barks and chirps, and even coming when called by name.^{[citation needed]}

In mid-2003, due to cross-contamination at a Madison, Wisconsin-area pet swap from an unquarantined Gambian pouched rat imported from Ghana, several prairie dogs in captivity acquired monkeypox, and subsequently a few humans were also infected. This led the CDC and FDA to issue a joint order banning the sale, trade, and transport within the United States of prairie dogs (with a few exceptions).^[22] The disease was never introduced to any wild populations. The European Union also banned importation of prairie dogs in response.^[23] While largely seen by exotic pet owners^[who?] and vendors^[who?] as unfair, the monkeypox scare was not the only zoonosis incident associated with prairie dogs.^{[citation needed]}

Prairie dogs are also very susceptible to bubonic plague, and many wild colonies have been wiped out by it.^{[24][25][26][27]} Also, in 2002 a large group of prairie dogs in captivity in Texas were found to have contracted tularemia.^[28] The prairie dog ban is frequently cited by the CDC as a successful response to the threat of zoonosis.^{[citation needed]}

Prairie dogs that were in captivity at the time of the ban in 2003 were allowed to be kept under a grandfather clause, but were not to be bought, traded, or sold and transport was only permitted to and from a veterinarian under quarantined procedures.^{[citation needed]}

On September 8, 2008, the FDA and CDC rescinded the ban making it once again legal to capture, sell, and transport prairie dogs effective immediately.^[29] Although the federal ban has been lifted, several States still have their own ban on prairie dogs in place.^{[citation needed]}

If in captivity, prairie dogs can live 8 years or more.^[30]

References

1. ^ Online Etymology Dictionary, prairie.
2. ^ ^{a b} "Journals of the Lewis and Clark expedition, "7th September Friday 1804. a verry Cold morning"". Libtextcenter.unl.edu. http://libtextcenter.unl.edu/examples/servlet/transform/tamino/Library/lewisandclarkjournals?&_xmlsrc=http://libtextcenter.unl.edu/lewisandclark/files/xml/1804-09-07.xml&_xslsrc=http://libtextcenter.unl.edu/lewisandclark/LCstyles.xsl. Retrieved 2009-02-09. 
3. ^ Deck, Annie. Revolt of the Cube-Berts. Business First of Buffalo. 14 Jan. 2000.
4. ^ "Journal of the Lewis and Clark Expedition, Tuesday July 1st 1806". Libtextcenter.unl.edu. http://libtextcenter.unl.edu/examples/servlet/transform/tamino/Library/lewisandclarkjournals?&_xmlsrc=http://libtextcenter.unl.edu/lewisandclark/files/xml/1806-07-01.xml&_xslsrc=http://libtextcenter.unl.edu/lewisandclark/LCstyles.xsl#n36070116. Retrieved 2009-02-09. 
5. ^ ^{a b c} Hoogland, J.L. (2002). "Sexual Dimorphism of Prairie Dogs", Journal of Mammology, 84(4): 1254-1266.
6. ^ ^{a b} Long, K. (2002) Prairie Dogs: A Wildlife Handbook, Boulder, CO: Johnson Books.
7. ^ ^{a b c d e f} Chance, G.E. (1976). "Wonders of Prairie Dogs", New York, NY: Dodd, Mead, and Company.
8. ^ ^{a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab} Hoogland, J.L. (1995) The Black- tailed Prairie Dog: Social Life of a Burrowing Mammal, Chicago, IL: The University of Chicago Press.
9. ^ ^{a b} Haynie, M., Van Den Bussche, R. A., Hoogland, J.L., & Gilbert, D.A. (2002) "Parentage, Multiple Paternity, and Breeding Success in Gunnison's and Utah Prairie Dogs", Journal of Mammalogy, 84 (4): 1244-1253.
10. ^ ^{a b c d e f} Hoogland, J.L. (1998) "Estrus and Copulation of Gunnison's Prairie Dogs", Journal of Mammalogy, 79(3):887-897.
11. ^ Foltz, D., and Hoogland, J.L. (1981) "Analysis of the Mating System in the Black- Tailed Prairie Dog (Cynomys Ludovicianus) by Likelihood of Paternity", Journal of Mammalogy 62(4):706-712.
12. ^ Hoogland, J.L. (1983) "Black- Tailed Prairie Dog Coteries are Cooperatively Breeding Units", The American Naturalist, 121(2):275-280.
13. ^ ^{a b c d} Slobodchikoff, C. N. (2002) "Cognition and Communication in Prairie Dogs", In: The Cognitive Animal (pp. 257-264), M. Beckoff, C. Allen, and G. M. Burghardt (eds) Cambridge: A Bradford Book.
14. ^ Prairie Dog Coalition - Associated Species
15. ^ Slobodchikoff, C. N., Judith Kiriazis, C. Fischer, and E. Creef (1991). "Semantic information distinguishing individual predators in the alarm calls of Gunnison's prairie dogs". Animal Behaviour 42 (5): 713–719. doi:10.1016/S0003-3472(05)80117-4. http://jan.ucc.nau.edu/~cns3/SlobodchikoffSemantics1991.pdf. 
16. ^ "Mammals of Texas: Black-tailed Prairie Dog". http://www.nsrl.ttu.edu/tmot1/cynoludo.htm. Retrieved 2006-04-18. 
17. ^ "The Diary of Virginia D. (Jones-Harlan) Barr b. 1866". Kansasheritage.org. 1940-05-22. http://www.kansasheritage.org/kssights/home/diary.htm. Retrieved 2009-02-09. 
18. ^ Open Season on “Varmints” For Saving Endangered Prairie Dogs, It’s the Eleventh Hour.
19. ^ "Prairie Dogs - Desert USA". DesertUSA. http://www.desertusa.com/dec96/du_pdogs.html. Retrieved 2009-02-09. 
20. ^ "CNN: What's that giant sucking sound on prairie?". http://www.cnn.com/EARTH/9612/16/sucking.dogs/. Retrieved 2009-10-10. 
21. ^ Pilny, A.. Prairie dog care and husbandry in Veterinary Clinics of North America: Exotic Animal Practice, Volume 7, Issue 2, Pages 269-282. 
22. ^ "CDC: Questions & Answers About Monkey Pox". http://www.cdc.gov/ncidod/monkeypox/qa.htm. Retrieved 2006-04-18. 
23. ^ "Born Free: EU bans rodent imports following monkeypox outbreak". bornfree.org.uk. June 2003. Archived from the original on 2006-05-01. http://web.archive.org/web/20060501182711/http://www.bornfree.org.uk/zoocheck/zcnews34.htm. Retrieved 2011-10-13. 
24. ^ "Plague and Black-Tailed Prairie Dogs". http://www.fws.gov/mountain-prairie/species/mammals/btprairiedog/plague.htm. 
25. ^ "Biologist Studies Plague and Prairie Dogs". http://campusapps.fullerton.edu/news/research/2004/stapp.html. 
26. ^ Robbins, Jim (2006-04-18). "Endangered, Rescued, Now in Trouble Again". The New York Times. http://www.nytimes.com/2006/04/18/science/18ferr.html?_r=1&oref=slogin. Retrieved 2010-05-22. 
27. ^ Hoogland, John L. (1995). The Black-Tailed Prairie Dog: Social Life of a Burrowing Mammal. University of Chicago Press. p. 80. ISBN 0-2263-5117-3. 
28. ^ "AVMA: Tularemia Outbreak Identified In Pet Prairie Dogs". http://www.avma.org/onlnews/javma/oct02/021001g.asp. Retrieved 2006-04-18. 
29. ^ Federal Register / Vol. 73, No. 174
30. ^ Prairie Dogs by Jen Green

External links

Media related to Prairie dogs at Wikimedia Commons

• Desert USA: Prairie Dogs
• Prairie dog
• Greycliff Prairie Dog Town State Park [1] [2]
• Dramatic Prairie Dog videos
• Prairie Dog Management, Kansas State University
• (Italian) Italian association of Prairie dogs