by Alex Gugel , all rights reserved
Utah Prairie Dogs
Bryce Canyon National Park Service U.S. Department of the Interior Bryce Canyon National Park Utah Prairie Dog (Cynomys parvidens) All photos by Kevin Doxstater Prairie Dogs are ground-dwelling members of the squirrel family found only in North America. There are five species within the genus and the Utah Prairie Dog is the smallest member of the group. Restricted to the southwestern corner of Utah, they are a threatened species that has suffered population declines due to habitat loss and other factors. Vital Statistics Utah Prairie Dogs range from 12 – 16 inches (30.5 – 40.6 cm) in length and weigh from 1 – 3 pounds (.45 – 1.4 kg). Color ranges from cinnamon to clay and they have a fairly distinct black eyebrow (or stripe) not seen in any of the other 4 prairie dog species. Their short tail is white tipped like that of their close relative the White-tailed Prairie Dog . Utah Prairie Dogs reach maturity in 1 year; females have a life span of about 8 years, males live approximately 5 years. Interestingly, they are the only nonfish vertebrate species endemic (found nowhere else in the world) to the State of Utah. Habitat and Diet Like the other members of the genus, Utah Prairie Dogs live in colonies or “towns” in meadows with short grasses. Individual colonies will be further divided into territories occupied by social groups or clans which are made up of (usually) 1 male, 1 or more females, and first-year offspring. The colonies can be occupied by as little as one clan to several. Burrows can be from 3 to 6 feet (.9 to 1.8 meters) deep and up to 15 feet (4.6 m) long with small chambers near the entrance to listen for activity above ground and larger, deeper chambers for sleeping and pup rearing. Mounds at the entrance to the burrows serve as lookout stations and to limit the amount of water entering the tunnels. for the remaining time. These include serving as a sentry looking for intruders or predators, play, mutual grooming, defense of territory or young, or burrow and nest construction. As noted above, there can be several territories within a colony and an intruder will be met with barking, chasing, or on occasion a fight may take place between adults. Pups will frequently cross over into other territories and play with neighboring pups, though sometimes an adult will chase the visitor away or even attack. As food sources become scarce in the late summer and early fall, neighboring clans begin to move into common feeding areas to forage. In most cases they are tolerant of others, though there are occasional fights between members of opposite clans in these common areas. Strictly diurnal (active during the day), Utah Prairie Dogs are rarely, if ever, seen outside their burrows before sunrise or after sunset. Approximately 60% of their time outside is spent foraging near the burrow, with other activities taking place Standing guard at the burrow’s entrance. Utah Prairie Dogs are primarily herbivores with a diet that consists of grasses, forbs, and seeds. When available they will also eat insects. They do not need to be near water as they glean most of their necessary intake from the plants they eat, though they will sometimes lick dew from plants in the morning. They return to their burrows during the middle portion of the day, especially on the hottest days of summer when moisture loss is greatest. Breeding Keystone Species The winters in southwestern Utah can be long, especially up on the plateaus, and, beginning in late October, Utah Prairie Dogs begin to retreat to their burrows to hibernate. In March, as Winter slowly gives way to Spring, they start to become active again and it is also the time to breed. Litter sizes range from 1 to 6 pups, with an average of 4, and are born in late April or early May following a 30–day gestation. The pups first emerge from the natal burrow some 6 weeks later and begin to explore the outside world. The pups spend the first week staying close to their mother, and studies indicate that knowing what foods to eat is learned during this period. As the weeks pass they quickly become more independent and are soon foraging with other members of the clan or in common areas with other dogs in All species of prairie dog are considered to be “keystone species” by biologists and the areas around prairie dog colonies support many diverse plant and animal species. Their burrows help to aerate the soil which, in turn, helps to promote plant growth. Grazing serves to “clip” plants, stimulating constant, healthy regrowth through the growing season. For example, here at Bryce Canyon, Mule Deer can frequently be seen during the summer months grazing in prairie dog colonies, seeking out this younger vegetation which is higher in nutritional content. Predator-prey relationships are part of all healthy ecosystems and prairie dogs are prey for a variety of species including hawks, eagles, weasels, badgers, owls, and rattlesnakes. In some cases, predators will then use the prairie dog’s burrows for shelter, denning, or nesting. As noted previously, a portion of a prairie dog’s time above ground is spent serving as a sentry for the clan because of this predator-prey relationship. A Threatened Existence Estimates are that in the 1920’s there were over 95,000 Utah Prairie Dogs whose range covered nearly 500,000 acres. By the early 1970’s there were only about 3,000 remaining in about 40 colonies. Ranchers poisoned or used other eradication methods to reduce competition from prairie dogs on rangeland used for grazing cattle and sheep, while farmers did the same due to crop losses caused by the rodents. Additionally, introduced Bubonic Plague, transmitted by fleas, has been responsible for wiping out entire colonies. In serious danger of extinction, Utah Prairie Dogs were listed as Endangered in 1973 and afforded protection under the Endangered Species Act. In 1974 they were reintroduced to Bryce Canyon National Park after having EXPERIENCE YOUR AMERICA™ Pups first emerge from the burrow about 6 weeks after they are born. the colony. As the summer draws to a close the pups are full grown and begin to disperse, sometimes near their home colony, though sometimes they move several miles away. Pups peaking out of their burrow. Prairie dogs have developed a complex set of vocalizations to warn others in the colony. Though nearly impossible for the human ear to detect the difference, their barks are specific to each type of predator. The “language” is so well developed that even a domestic dog will trigger a different bark than a coyote or fox - and the response by other colony members is different, too. Studies have shown that younger prairie dogs, like human children, have to learn the language and cannot fully communicate until they are about 4 to 5 months old. A prairie dog’s diet consists mainly of plants been eradicated in the 1950’s and the park is now home to about 10 colonies averaging 200 total individuals. With populations of Utah Prairie Dogs increasing slightly their status was changed in 1984 from endangered to threatened where it remains today.