DENVER, Oct. 4, 5:07 p.m. - The state Wildlife Division estimates Colorado has about 788,000 acres of black-tailed prairie dog colonies, up 25 percent from five years ago.

The survey results, announced Tuesday, are part of the state's effort to document the health of the animal.

In the late 1990s, some environmental groups questioned how many black-tailed prairie dogs were left in the state and asked the federal government to declare them endangered.

The prairie dog information will be incorporated in the a conservation plan for grassland species, designed to ensure the health of the mountain plover, burrowing owl, swift fox, ferruginous hawk, prairie dogs and other animals dependent on prairie dogs for their survival, while addressing the interests and rights of private landowners.

The latest findings show a marked increase in occupied acreage of black-tailed prairie dog colonies since the DOW's last survey in 2002, reporting an estimated 630,000 acres of black-tailed prairie dog towns.

“We used low-flying aircraft to do aerial surveys, and then followed up by sending in ground crews to verify the findings reported from the air,” said Eric Odell, Grassland Species Conservation Coordinator for the DOW. The aerial surveys located 814,000 acres of potential black tailed prairie dog towns. Based on the findings of the ground crews, the DOW estimates 788,000 acres are occupied.

“Flights started last fall and continued until we traversed the entire eastern portion of the state,” Odell said. “In the meantime, ground crews contacted randomly selected private landowners to ask permission to access their property in order to verify several of the colonies identified from the air.” Eighty percent of the prairie dog colonies found were on private land.

Because aircraft were not able to fly over metropolitan areas such as Denver, Boulder, Fort Collins, or Colorado Springs, estimates should be considered a minimum estimate of occupied acreage within Colorado.

Periodic surveys are part of an ongoing effort by the DOW to accurately estimate the acreage occupied by black-tailed prairie dogs. Data collected will be incorporated in the DOW's Conservation Plan for Grassland Species.

The goal of the Conservation Plan for Grassland Species is to ensure the viability of species such as mountain plover, burrowing owl, swift fox, ferruginous hawk, and prairie dogs while addressing the interests and rights of private landowners.

The DOW's black-tailed prairie dog survey and Grassland Species Conservation Plan have been hailed by both conservation groups and private landowner groups.

Renee Rondeau, director of the nonprofit Colorado Natural Heritage Program that specializes in wildlife conservation, said, “Through this information we can make valuable inferences that demonstrate the importance of private ranches in conserving imperiled species that are tightly associated with prairie dog habitat.”

“The Division of Wildlife's acreage survey of black tailed prairie dogs illustrates a science based approach that validates that the species is healthy and sustainable in Colorado,” said Kenny Rogers, Colorado Cattlemen's Association President. Rogers went on to say, “The significance of this increase in acreage is a testament to the private landowners by way of the habitat they provide.”

Alan Foutz, president of the Colorado Farm Bureau agreed. “Private landowners have said for years that the population of black-tailed prairie dogs was not in jeopardy,” said Foutz. “This study, done with cooperative efforts of private landowners is an important step to proving that the prairie dog has a healthy population.”

Why Survey Prairie Dogs?

Questions about the health and well being of black-tailed prairie dogs were raised by environmental groups in the late 1990s. The groups petitioned the federal government to declare black-tailed prairie dogs as an endangered species.

In cooperation with the United States Fish and Wildlife Service, Colorado and other western states began gathering data about the number of acres where black-tailed prairie dogs live.

In 2002, the last year the DOW did an aerial survey, approximately 630,000 acres of black-tailed prairie dog towns were documented. As with nearly all wildlife species, prairie dog populations are subject to natural cycles, which is why the DOW re-surveyed eastern Colorado this year.

“The earlier survey gave us a baseline for a long-term monitoring program in Colorado, but it is important to repeat those efforts to follow trends,” Odell said. “By doing multiple surveys we can address the amount of variation over time.”

One issue biologists recognize as a factor in fluctuating prairie dog populations is plague. Odell says that disease can cause substantial declines in localized areas, but colonies in other areas might expand during the same time period. A fluctuation in existing colonies, plus the settlement of new colonies, creates the potential for highly variable acreage from year to year.

Colorado is home to three species of prairie dogs – the black-tailed, the white-tailed and the Gunnison. Black-tailed prairie dogs are the most common species. They populate the Front Range and eastern plains. White-tailed and Gunnison prairie dogs are generally found west of I-25.

Although they are called prairie dogs, prairie dogs are members of the squirrel family which includes ground squirrels, chipmunks, marmots, and tree squirrels.

The USFWS ruled in 2004 that there are sufficient numbers of black-tailed prairie dogs in the U.S. that they do not warrant protection under the Endangered Species Act.

Colorado regulates seasonal prairie dog shooting on public land. Landowners are allowed to control prairie dogs on private property if their numbers become a problem.

Prairie Dog Facts

Adult black-tailed prairie dogs weigh from one to three pounds, and are 14 to 17 inches long. Gunnison and white-tailed prairie dogs are smaller.

Females have only one litter each year. The typical litter size is three to five pups, but there can be as many as eight in a litter.

Prairie dogs have a life-span of three to five years in the wild.

Prairie dogs are known for creating an elaborate system of underground burrows.

Prairie dogs communicate using a variety of calls, especially the “alarm” or “bark” to alert the community to danger.

Prairie dogs are an integral part of the ecosystem. Many other wildlife species, including black-footed ferrets, rattlesnakes, burrowing owls, eagles, hawks, badgers, and weasels interact with, or depend on, prairie dog towns for their survival.

Prairie dogs eat grass, seeds and some insects. Prairie dogs “clip” grass to keep it low so they can see predators approaching from a distance.

Black-tailed prairie dogs are active year around. White-tailed and Gunnison prairie dogs hibernate during the winter.

The tail of a black-tailed prairie dog is long compared to other prairie dog species and is conspicuously tipped with black hairs. White-tailed prairie dogs have a white tip on the tail and dark cheek patches that extend to above the eye. Gunnison prairie dogs are the smallest of Colorado's prairie dogs. The top of the head and cheeks are darker than the rest of the body but do not show the striking pattern exhibited by the white-tailed prairie dog. The terminal one-third of the tail is light gray in color.

Black-tailed prairie dogs are found along the Front Range and eastern plains. White-tailed prairie dogs inhabit northwestern and west-central Colorado. Gunnison's prairie dogs are found in southwestern and south-central Colorado.