Prairie dog
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The prairie dog (Cynomys) is a small, burrowing rodent native to the grasslands of North America. On average, this stout-bodied rodent will grow to be between 12 and 16 inches (30 and 40 cm) long, including its short tail. They are found throughout the United States, Canada, and Mexico. In the United States, prairie dogs are primarily found west of the Mississippi River, though they have also been introduced into a few eastern locales.
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[edit] Etymology
Prairie dogs are named for their habitat and warning call, which sounds similar to a dog's bark. According to the Online Etymology Dictionary, the name is attested from at least 1774.<ref>Online Etymology Dictionary, prairie.</ref> The 1804 journals of the Lewis and Clark expedition note that in September of 1804, they "discovered a Village of an annamale the french Call the Prarie Dog" <ref name="sept7">Journals of the Lewis and Clark expedition, "7th September Friday 1804. a verry Cold morning"</ref>
Its genus, Cynomys, derives from the Greek for "mouse dog."
[edit] Biology and behavior
The highly-social prairie dogs live in large colonies or "towns" — collections of prairie dog families that can span many acres of land and lead more than 10 meters into the ground. Families tend to consist of one male and 2 to 4 females, though some consist of multiple males and females or just a single creature. Colonies are fixed, and the complex tunnel system they use can sustain for dozens of years.<ref name="slogobod2002">Slobodchikoff, C. N. (2002). "Cognition and communication in prairie dogs," The Cognitive Animal, 257-264, MIT Press.</ref>
Prairie dog tunnel systems are believed to help channel rainwater into the water table to prevent runoff and erosion, and also can serve to change the composition of the soil in a region by reversing soil compaction that can be a result of cattle grazing. The tunnels have separate rooms for sleeping, eating, babysitting, and just sitting. Prairie dogs are also known to control the populations of several weed species, such as mesquite, which has been found to overrun some lands where prairie dogs are no longer found.
The prairie dog is well-adapted to predators. Using its dichromatic color vision, it can detect predators from afar and then alert other prairie dogs to the danger with a special, high-pitched call. Con Slobodchikoff and others assert that prairie dogs use a sophisticated system of vocal communication to describe specific predators.<ref name="slogobod2002" /><ref>Scientist: Prairie Dogs Have Own Language. Retrieved on 2006-04-18.</ref> Prairie dogs also trim the vegetation around their colonies, perhaps to remove any cover for predators. <ref>Nebraska Game and Park Commission: the Prairie Dog.</ref> Their burrows generally contain several routes of escape.<ref name="slogobod2002" />
The prairie dog is chiefly herbivorous, though it eats some insects. It feeds primarily on grasses and, in the fall, broadleaf forbs. They have up to 4 pups yearly, which are born blind and furless and need about 30 days of close nurturing by their mother.
[edit] Conservation status
Ecologists consider this rodent to be a keystone species, for multiple reasons. They are an important prey species, being the primary diet in prairie species such as the Black-footed Ferret, the Swift Fox, the Golden Eagle, the Badger, and the 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 Bison, Pronghorn and Mule Deer have shown a proclivity for grazing on the same land used by prairie dogs[citation needed]. It is believed that they prefer the vegetative conditions after prairie dogs have foraged through the area.
Despite their ecological importance, prairie dogs are frequently exterminated from ranchland, being labelled as a pest because they are capable of damaging crops<ref>Mammals of Texas: Black-tailed Prairie Dog. Retrieved on 2006-04-18.</ref> and often clear the immediate area around their burrows of most vegetation. This program of extermination probably originated in the nineteenth century, hundreds of years after the Native Americans began using prairie dogs as a food source.<ref name="slobod1991">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, 713-719.</ref>
Prairie dog habitat has been impacted by encroachment of human development, and removal by ranchers and farmers. Numbers of all species of prairie dog have been greatly reduced as a result. The largest remaining community is comprised of Black-tailed Prairie Dogs.
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. They are difficult to breed in captivity, but it has been done on several occasions. Removing them from the wild was a far more common method of supplying the market demand.
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.
In mid-2003, due to cross-contamination in a Chicago-area pet store from an unquarantined Gambian pouched rat imported from Africa, several prairie dogs in captivity acquired monkey pox, and subsequently a few humans were also infected. This led the CDC to institute an outright ban on the sale, trade, and transport of prairie dogs within the United States.<ref>CDC: Questions & Answers About Monkey Pox. Retrieved on 2006-04-18.</ref> The disease was never introduced to any wild populations. The European Union also banned importation of prairie dogs in response.<ref>Born Free: EU bans rodent imports following monkeypox outbreak. Retrieved on 2006-04-18.</ref> While largely seen by exotic pet owners and vendors as unfair, the monkey pox scare was not the only zoonosis incident associated with prairie dogs. Prairie dogs are also very susceptible to bubonic plague, and several wild colonies have been wiped out by it.[citation needed] Also, in 2002, a large group of prairie dogs in captivity in Texas were found to have contracted tularemia.<ref>AVMA: Tularemia Outbreak Identified In Pet Prairie Dogs. Retrieved on 2006-04-18.</ref> Prairie dogs are not natural carriers of any of the three diseases, but the ban is believed to be in the best interests of protecting the public and there are no intentions of ever lifting it. The prairie dog ban is frequently cited by the CDC as a successful response to the threat of zoonosis.
Prairie dogs that were in captivity at the time of the ban in 2003 are allowed to be kept under a grandfather clause, but they may not be bought, traded, or sold and transport is only permitted to and from a veterinarian under proper quarantine procedures.
[edit] 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.<ref name="sept7" /> Lewis described it in more detail in 1806, calling it the "barking squirrel." <ref>Journal of the Lewis and Clark Expedition, Tuesday July 1st 1806.</ref>
