Endangered Species Handbook

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Persecution and Hunting

Rodent Control

Prior to settlement of North America, prairie dogs of many species inhabited towns of burrows that covered some 98 million acres of shortgrass prairies, from southern Canada to Mexico. One prairie dog town in the Texas Panhandle stretched over 25,000 square miles and held an estimated 400 million animals (Dold 1998). Prior to the 19th century, they are thought to have numbered 5 billion animals (DeBlieu 1993). These towns have since been destroyed, the prairie dogs killed, and the habitat used for agriculture, pastureland and development. A keystone species, prairie dogs create habitat for hundreds of other animals who live in their complex burrow systems. These rodents have been driven to endangered status after centuries of persecution and poison campaigns that were based on the belief by cattle ranchers that prairie dogs ate too much grass, depriving cattle of fodder. The US government sponsored the destruction of prairie dog towns beginning in 1900. The poisoning program was bolstered by inaccurate information from the US Biological Survey, which stated in 1902 that prairie dogs decreased productivity of grasslands by 50 to 75 percent (Dold 1998). Poison bait was distributed in the towns, gasoline was poured into their burrows and set afire, and they were shot by the thousands. A highly toxic poison, 1080, was used from the 1960s on, devastating prairie dog towns and killing vast numbers of animals, from foxes to Golden Eagles, who fed on the poisoned prairie dogs. This reduced prairie dog habitat to about 1.5 million acres, a fraction of their original range.
Modern biological research has unveiled the truth about the effect of these rodents on grasslands. Rich Reading, Director of Conservation Biology at the Denver Zoological Foundation, stated flatly that the Biological Survey's figures claiming that prairie dogs reduced grass by up to 75 percent, were "vastly in error" (Dold 1998). Studies by Dan Uresk, a Forest Service biologist, have concluded that prairie dogs eat only a small percentage of grass--from 4 to 7 percent (Dold 1998). James Detling of Colorado State University in Fort Collins has found that prairie dogs are natural fertilizers, whose incessant grass clipping increases the protein content and digestibility of grass (Long 1998). Other studies have examined the claims of cattle ranchers against prairie dogs and have demonstrated again and again that these rodents actually improve forage quality for livestock and, by cropping the shortgrass prairie, stimulate it to grow, increasing the amount of grasses around the towns (Wuerthner 1996). The American Bison prospered in herds of 50 million, much of the species range lying within prairie dog towns of the short-grass prairies. Their major predator, the highly endangered Black-footed Ferret (Mustela nigripes), has been eliminated in the wild as a result of poisoning and shooting campaigns. At least 130 grassland species are associated with prairie dog towns (Godbey and Biggins 1994), and up to 170 vertebrate species have been seen in these towns.
Another complaint of cattlemen, that cattle fall into prairie dog burrows and break their legs, has also been refuted. Don Sharps, a wildlife consultant, asked an audience of 200 ranchers if any of them knew of a case of a horse or cow that had broken its leg in a prairie dog town, and no one said yes (Dold 1998). Such prejudices are passed down from generation to generation and fuel the persecution programs against these ecologically important rodents.
Slow-acting poisons, such as zinc phosphide, are used by many animal damage control programs. This chemical takes up to 12 hours to kill prairie dogs, who suffer extremely painful deaths (Wuerthner 1996). Another technique is the placement of gas cartridges in prairie dog burrows. These are ignited and burn the prairie dogs alive (Wuerthner 1996). On federal lands, these programs are conducted by the Wildlife Services unit of the Department of Agriculture at public expense. In the 1980s, more than $6 million was spent to eradicate 460,000 acres of dog towns on the Pine Ridge Indian Reservation in South Dakota (Line 1997). This was the largest remaining prairie dog town in the United States (Dold 1998) and the site of the only population of Black-footed Ferrets known to exist in the 1970s. In 1993, Animal Damage Control (now called “Wildlife Services”) used, sold or distributed 220,000 fumitoxin tablets, 60,000 gas cartridges, and 21,000 pounds of zinc phosphate baits in the northern plains states to eradicate prairie dogs (Wuerthner 1996).
Studies about prairie dogs have revealed them to be surprisingly intelligent. They communicate in yips and chirps, some of which are warnings to other members of the town. A study by Professor Con Slobodchikoff of Northern Arizona University has revealed that prairie dogs’ calls convey specific information, such as what size a predator is, what type of animal, its speed of travel and level of threat (Dold 1998). Slobodchikoff created experiments in which two people walked through a prairie dog town that had experienced hunting; one carried a simulated rifle, while the other did not. The prairie dogs gave different calls for each person, and when the "hunter" returned in a few weeks without his rifle, they still gave the call for a man carrying a rifle (Dold 1998). Such communication goes far beyond what most people consider rodents to be capable of and shows their ability to react to a variety of threats, including the most serious one, human beings. Unfortunately, their warnings could not protect them from poison, shooting, and even bulldozing of their burrows.
Knowledge about the true role that prairie dogs play in grassland ecosystems has yet to reach most ranchers and others who have a hatred for these rodents that seems to reach no bounds. Many compare notes on how many prairie dogs they have killed, usually by high-powered bullets that cause them to disintegrate on contact (Long 1998). One group in eastern Colorado with 30 members calls themselves the Varmint Militia and kills prairie dogs as a sport. They recently spent two full days shooting prairie dogs until activity in the prairie dog town slowed (Long 1998). One militiaman bragged of having shot 20,000 prairie dogs and wants to retire from his exterminating business to shoot them full time (Long 1998). These shooters recount with glee the story of a recent protest. Some animal rights protesters tried to stop one of these hunts and chained themselves together, refusing to move; the Varmint Militia called the Kit Carson County sheriff, who placed them in jail for the weekend (Long 1998).
Although private shooting may be difficult to stop, many biologists and conservationists have recommended that all government poisoning and shooting on public land be halted and that subsidies be offered to ranchers who do not kill prairie dogs on their property (DeBlieu 1993). Unfortunately, no action has been taken in this direction.
Sport hunting of these rodents is encouraged by state game departments, and many towns organize hunts as a form of recreation. These hunts, which often involve the killing of hundreds of prairie dogs in a single afternoon, are taking a high toll of these declining animals in many areas (Wuerthner 1996). A South Dakota organization, Varmint Hunters Association, brags that its 45,000 members do society a favor by killing prairie dogs. The vice president, Marc Minkin, told a reporter, "I'd like to be able to step out my back door in the morning and take a couple of shots before my morning coffee" (Dold 1998). The organized prairie dog shoots draw "hunters" from around the country; one hunt held in Nucla, Colorado, obliterated an entire town (Dold 1998). This hunt, which involves taking pot shots at prairie dogs emerging from their burrows, which they must do to feed, is totally unsportsmanlike--a virtual slaughter.
Even in national parks, poisoning takes place as a result of pressure from neighboring ranchers. In spite of abundant habitat in Theodore Roosevelt National Park, Badlands National Park, Wind Cave National Park and various national monuments in the Great Plains, only 6,000 acres of prairie dog towns have been protected (Wuerthner 1996). In most cases, park authorities have been threatened with lawsuits unless they poison prairie dogs. In South Dakota, home of Badlands National Park, a prime potential area for reintroduction of the endangered Black-footed Ferret, the state has declared prairie dogs to be noxious pests and mandates their control (Long 1998). At Devils Tower National Monument in Wyoming, the park rangers use rifles and poison to thin the ranks of its prairie dog colony (Long 1998).
Increasingly, development in the form of housing complexes, malls, highways and industrial centers, has gobbled up millions of acres of land in the West, much of it inhabited by prairie dogs. Some developers merely bulldoze the towns, while others pay to have a company use a giant vacuum cleaner that sucks prairie dogs out of the ground amid deafening noise similar to that of a jet airplane taking off. The proud inventor of this machine bragged that it was non-lethal, and the rodents could then be killed humanely or otherwise disposed of to allow development programs to proceed. In fact, most of the prairie dogs taken in this manner are killed or injured in the process (Dold 1998). The trauma involved for the prairie dogs must be extreme. Many of the prairie dogs removed from their burrows have been offered for sale as pets, advertised in eastern newspapers. Although loveable and cute, these animals are not suitable house pets because they are wild rodents who require extensive dirt to burrow in. They cannot adjust to the unnatural environment of a home. Unfortunately, this new invention has been given favorable publicity in the media. The majority of prairie dogs that survive this operation end up as pet food, according to CNN (December 15, 1996).
A more humane program involves the moving of prairie dogs to safer environments. A Colorado organization, Prairie Ecosystem Conservation Alliance, hoses prairie dog burrows with water and a biodegradable dish soap that creates frothy suds below ground. The suds irritate the eyes of the prairie dogs, who come to the surface where members of the Alliance are waiting to scoop them up and place them in carriers. They then truck them to a safe area, preferably one with empty burrows, and release them (Dold 1998). An even better solution is to save the towns, since the latter method will not save all the other animals inhabiting the burrows. The city of Boulder, Colorado, became the first town in the state to officially designate land to protect prairie dogs. In 1987 it set aside a preserve for prairie dogs, which now covers almost 5,000 acres (Dold 1998). Fort Collins, further north, began with a reserve of 268 acres and now has 1,700 acres (Dold 1998).
A Native American Gros Ventre tribesman, Mike Fox, has come full circle, from sponsoring prairie dog shoots on the Fort Belknap Indian Reservation in Montana to understanding their positive effect on grasslands by watching Bison graze near the towns on the "best grass around" (Long 1998). There are 400 American Bison on the reservation, and Fox, who manages the reservation's wildlife program, has sharply curtailed prairie dog shooting and accepted 23 Black-footed Ferrets to be reintroduced into the 500,000 acres of prairie on the reservation (Long 1998). He tells Indian ranchers, who still kill prairie dogs, that these animals were here before, and the ferret is not a new animal, but an old one returning (Long 1998).
All but 2 percent of original prairie dog populations are now gone, having been poisoned out to make way for livestock or agriculture. The majority of remaining towns are still unprotected, and the poisoning continues. Grasslands with prairie dogs support far higher densities of mammals, birds and other wildlife than those without them.
Several prairie dog species have been driven to near extinction. The Utah Prairie Dog (Cynomys parvidens), native to south-central Utah, became endangered from these programs and the loss of habitat to livestock and agriculture. Listed on the US Endangered Species Act, this species has a restricted range in southwest Utah, and after poisoning programs, its population fell from an estimated 95,000 animals in 1920 to only 3,300 in 1972 (Nowak 1999). Through protection accorded by the US Endangered Species Act, Utah Prairie Dogs began to rebound, and by 1984, the species was downgraded from Endangered to Threatened on the US Endangered Species Act. Populations of prairie dogs fluctuate widely, and counts of Utah Prairie Dogs in the early 1990s ranged from 6,400 in the fall to 24,000 after they had pups in the spring (Nowak 1999). The species has recovered somewhat overall, mainly as a result of the Fish and Wildlife Service program of transplanting prairie dogs from private to public lands (Turbak 1993). Initially, many of the released prairie dogs failed to survive, and not until they began releasing males in the spring, who industriously spent the summer excavating burrows to accommodate other prairie dogs released in the fall, did transplants succeed (Turbak 1993). Utah Prairie Dogs hibernate each winter in compartments in the complex maze of their underground tunnels.
Although some Utah Prairie Dogs have been placed on public land, 60 percent of them still live on private land, where special US Endangered Species Act regulations allow farmers and ranchers to shoot or trap an annual quota of prairie dogs; a high of 6,000 were killed one year, and in 1992, 1,543 were killed (Turbak 1993). Education campaigns and tax incentives to protect prairie dog towns would be far preferable to quota systems.
Mexican Prairie Dogs (Cynomys mexicanus) of southern Coahuila and northern San Luis Potos, Mexico, have declined as their habitat has been converted to agriculture and grazing land for livestock, and many colonies were exterminated by poisoning. The largest remaining town covers only 4,400 hectares (Nowak 1999). The species is listed as Endangered by the US Endangered Species Act as well as by the 2000 IUCN Red List of Threatened Species.
A third species, the Black-tailed Prairie Dog (Cynomys ludovicianus) has declined by 98 to 99 percent (Wuerthner 1996) in a range which once extended from Montana and southern Saskatchewan to northern Mexico (Nowak 1999). The Biodiversity Legal Foundation in Colorado filed a petition in October 1994 to list it as a Category 2 species under the US Endangered Species Act, a category just below Threatened. Although the Fish and Wildlife Service's own biologists supported this listing, the petition was denied after political pressure from ranchers (Wuerthner 1996).
Thus, at least three of North America's five species of prairie dogs are in grave danger of extinction, and the remaining two have declined precipitously. Their ecosystems are threatened as well, as are many of the species that depend on them. Although they are extremely photogenic and likeable, prairie dogs are not ecotourist attractions at present. With protection and more publicity, such as nature films and education programs, they could become so, and this would enhance their conservation.
Conservationists have proposed some huge reserves for prairie dogs that would link remnant populations in parts of the West, where much of the land is now under the control of the Bureau of Land Management of the Department of the Interior. The latter department favors cattle ranchers more than prairie dogs, but with outside pressure and publicity, such a plan might become reality. The Fish and Wildlife Service has had difficulty locating prairie dog towns that are protected from poison programs in which to reintroduce captive-bred Black-footed Ferrets.
For their long-term survival, prairie dogs need extremely large territories. At present, fragmented populations, which are often reduced to a few hundred animals widely separated from the nearest prairie dog town, have lost viability from lack of genetic interchange, and some scientists fear that their natural behavior may be altered by this isolation. These loveable animals need more friends to speak out on their behalf and demand that they be protected from poisoning, "sport" hunting and other persecutions, and that sanctuaries be established.
Economically, they may be worth far more alive than dead. The potential for using prairie dogs as a focal point for ecotourism is great. Tourists would be delighted by their behavior and fascinated to see the rich wildlife that inhabits their towns.

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