In the Midwest of the United States the matter of whether prairie dogs are a threatened species or an over populated public health nuisance that causes severe economic damage has been raging for decades. This article is the first in a series of articles we will publish that will cover this issue.
I recently received an email from a resident of Lawton Oklahoma who was concerned about actions taken by their city council to fumigate prairie dog colonies in a city park. This extermination was carried out in the dark of the night, allegedly without prior notification to citizens. I could have simply sent the writer an email suggesting a course of action that she might take to determine whether the killing of the prairie dogs had been done legally and in accordance with prescribed safety guidelines. I could have done that, but I didn't. The whole prairie dog debate had been firmly implanted in my mind nearly thirty years earlier.
Years ago I remember receiving a postcard printed by the Audubon Society stating that the black tailed prairie dog was non-existent except on wildlife preserves. I knew differently, because I was a college professor, the Director of the Natural Resource Center and a rangeland researcher at Oglala Lakota College on the Pine Ridge Indian Reservation. At that time, 70% of the tribal rangeland on the one and a half million-acre reservation was infested with these "non-existent" prairie dogs, rendering much of the rangeland unsuitable for cattle grazing. While I was confronted with the problem of how to deal with the seemingly endless number of the little critters, I still remember spending many evenings sitting on a knobby blanket of buffalo grass and watching the delightful little fellows as they whistled back and forth from one mound to another. I couldn't help but wonder about what sort of gossip they were spreading across the prairie. Somehow I always hoped that there would be enough prairie dogs left for my grandchildren to enjoy.
The prairie dog dilemma exemplifies the polarization that results when there is a conflict between humans and another animal occupying the same habitat. There is always a group of individuals at one end of the spectrum who tend to blame the competing organism for every malady that threatens the human position in the habitat.
At the other end of the spectrum is a group that would choose to protect animals. This includes those who believe that all animals have feelings and "rights", and preservationists who are interested in protecting the diversity of Earth's species.
With extremists the passion runs high, and there is no common ground. It basically comes down to a choice between absolute protection of the environmental competitor or total annihilation.
Fortunately, however, most stands are more moderate. Some would like to have control over the "invaders" of their property but they may fear that the use of chemicals could cause undo harm to the health of local residents. Others are searching for an effective environmentally friendly means of keeping the prairie dog population in check.
Like most rodents, prairie dogs reproduce quickly. They can produce at least one litter of pups a year with 4 - 6 pups per litter (3, 4). Most of their natural predators other than humans have been eliminated or greatly reduced in number. As a result, there is little environmental pressure to keep their numbers in check. Their numbers may increase rapidly, and colonies expand to meet the new "housing demand." Their expansion encroaches upon grazing land, golf courses, city parks and even airport runways (11, 12). The only exception is in regions where the sylvatic plague is prevalent as it is 100% fatal to prairie dogs. Sylvatic plague is the name given to a Yersinia pestis infection in animals other than humans (in humans it is referred to as Bubonic Plague).
Threatened with fines of a $100,000 a day fine from the Federal Aviation Administration, the City of Albuquerque, NM reluctantly agreed to exterminate an infestation of prairie dogs at the airport in March of 2007. The city had been attempting to catch and relocate the animals, but changed tactics because of possible safety problems associated with the prairie-dog colonies (11).
Oftentimes for less pertinent reasons officials may feel that prairie dogs must be exterminated. Groups looking for reasons to justify the removal of all prairie dogs from a given area use the threat of injury to park visitors who fall into holes. Others resort to instilling the fear of possible outbreaks of bubonic plague from infected prairie dogs.
What is interesting to note about the plague fears is that according to CDC only three people in the entire United States were infected with the bubonic plague between 2002 and 2003, all of whom survived (14). There is also no case on record of a human having contracted bubonic plague from a prairie dog. However in California alone, between 1982 and 1992 over 200 individuals were accidentally poisoned by the commonly used rodenticide aluminum phosphide or phosphine. At least two of these individuals died (8). It would seem then that the poison most often used to control prairie dogs is much more likely to harm humans than bubonic plague from any source, let alone a prairie dog.
The black tailed prairie dog is currently found in 10 States including Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, and Wyoming. It once was found in Arizona, but has been declared "expatriated" from that state (13, 4).
The black tailed prairie dog was added to the list of species "eligible for inclusion" as a Threatened Species of the Endangered Species Act after a petition was submitted to declare the black tailed prairie dog a Threatened Species in 1998. The U.S. Fish and Game Service found that protection was warranted, but could not add it to the list because other species were in more immediate need of protection. On August 12, 2004 the black tailed prairie dog was officially removed from candidate status on the "Threatened Species" list of the Endangered Species Act because it does not meet the criteria (3). Its present population is estimated at more than 18 million.
It should be noted that in making the decision, the Fish and Wildlife Service located in Lakewood, Colorado focused its research on a few large black-tailed prairie dog populations impacted by sylvatic plague and assumed that population losses at these sites were indicative of losses across the species' entire range (3). That fact coupled with the outcry of citizens who wanted to preserve the cute little rodents might explain how the Fish and Wildlife Service came to the conclusion that placed the black tailed prairie dog under the protection of the Endangered Species Act to begin with (3).
It is likely that the measures used to control prairie dogs, as well as the extent to which they will be controlled, will change in the near future. There are many new methods of prairie dog control being used. Vacuuming or flushing dens with soapy water have facilitated removing and relocating prairie dogs with minimal trauma. Flattening the dens with shockwaves is a promising newcomer to the prairie dog control arsenal. Boulder, Colorado has turned prairie dog infested areas of a park into a temporary dog park. Apparently, prairie dogs are not too fond of their namesakes, and will relocate rather than coexist with them. Only time will tell if it works.
Another group known "restorationists" are questioning how much rangeland damage can be attributed purely to prairie dog infestation. They contend that since the prairie dog is a keystone species, care should be taken to preserve the integrity of the prairie dog (9). Restorationists claim that the wellbeing of the prairie dog is an indication of the wellbeing of the rangeland. If the rangeland had the proper balance of species, there would be enough predators to keep the prairie dogs in check, and the prairie dog would actually be beneficial to the community as a whole.
There is little doubt that there must be some control of the prairie dog population. At the same time, it is important that control does not translate to annihilation or result in the prairie dog being "expatriated" from 10 more states. If the restorationists turn out to be right, and by proper range management we can live in harmony with the prairie dog that would put a new spin on the business of prairie dog management.
For more specific information on specific prairie dog control methods, the debate as to whether the prairie dog is a friend or foe to well managed grazing lands, continue to our next article in this series "Prairie Dog Control Part I: Non-Lethal Control Techniques".
Other articles in this series:
If you need to cite this page, you can copy this text:
Roberta Barbalace. Prairie Dogs: A Threatened Species or Public Health Nuisance?. EnvironmentalChemistry.com. Mar. 20, 2007. Accessed on-line: 3/7/2014