How a plan for open space near Stapleton became open season on prairie dogs
Photo: Thinkstock; Photo Illustration: Jay Vollmar
More than most people, perhaps, Stapleton resident Patricia Olson feels a strong connection to animals. A veterinarian and former CEO of the world's largest nonprofit dedicated to animal health sciences, she's helped fund research studies on everything from housecats to sea lions to gorillas.
But even though she lives in a place that was once a vast grassland, Olson had never paid much attention to prairie dogs. Not until a contractor hired by Forest City, the developer in charge of transforming Stapleton from a decommissioned airport into a mixed-use, amenity-stuffed community of tomorrow, began gassing them right around the corner from her home.
A yipping, thriving colony of black-tailed prairie dogs had taken over a vacant stretch of land on the south side of East 26th Avenue, the dividing line between Aurora and Denver on the east side of Stapleton. Like many neighbors, Olson had become so accustomed to the colony that she drove slowly on 26th to avoid mashing the occasional stray darting in and out of the street. But one day, close to Thanksgiving 2011, she came home to find the land being prepped for construction and men sealing up the burrows.
The men explained to Olson that the area was slated to become a children's playground and "natural park." But first they had to exterminate the prairie dogs.
"I tried to find out why they were doing it and what poison they were using," Olson recalls. "And that's when I got really upset."
Over the next few months, Olson read up on prairie dogs — their behavior and their role as a keystone species in the shortgrass prairie ecosystem, providing food and habitat for a wide range of animals, insects and plants. She learned more than she wanted to know about the poison the men were using: aluminum phosphide, a rodenticide that, when ingested, produces highly toxic phosphine gas, internal bleeding — and, in some cases, an agonizingly slow death.
She also contacted biologists, prairie-dog advocate groups and neighborhood associations, and realized that she was hardly the only one alarmed. Current eradication efforts around the metro area range from the march of RTD's FasTracks light-rail projects through miles of prairie-dog habitat to battles over small colonies abutting ballfields or park land to several areas of conflict within Stapleton itself. One teacher took 23 first-graders on a "nature walk" to another colony in Stapleton, only to find workers packing the burrows with poison — a grimmer lesson in urban-wildlife management than the kids had anticipated. An older class on a field trip discovered abandoned canisters of aluminum phosphide, labeled KEEP OUT OF REACH OF CHILDREN, lying around the burrows on East 26th Avenue.
Last fall, after photographing some of the canisters herself, Olson filed a complaint with the Colorado Department of Agriculture, which regulates the use of aluminum phosphide in pest control. John Scott, manager of the agency's pesticides program, says the investigation is ongoing, but points out that the poison was applied a year before the complaint. "We determined there was no immediate public or environmental potential for harm," he says.
The company switched poisons as a result of the complaints, notes Forest City spokesman Tom Gleason: "Some of the animal activists told us that they thought carbon monoxide was more humane, so we went to that."
Choice of lethal compounds aside, Olson thought the entire procedure smacked of bad policy. A recent study in Science suggests that prairie dogs that lose close kin disperse further, possibly in search of their lost relatives; sure enough, in recent months new burrows have appeared on 26th, flanking either side of the playground under construction. And what's the point, Olson wondered, of creating a "natural" park in which one of the most essential natural components has been removed?
"If you poison them, they go looking for Aunt Mildred and disperse," Olson says. "That's exactly what happened. It's not effective. It's not humane. So what are they doing?"
Despite the outcry, developers and park managers are doing what they've always done with Colorado's prairie dogs: waging war on them as if dealing with mosquitoes or noxious weeds. Ranchers have long regarded the lowly rodent as a flea-bitten, grass-stripping, plague-infested nuisance, and that distorted characterization has strongly shaped how urban as well as rural colonies are treated. For a keystone species, prairie dogs have virtually no protection from annihilation, particularly on private land; with little fuss, they can be shot, poisoned or even buried alive with bulldozers. State law makes it extremely difficult to relocate them across county lines, and surveys indicate that their habitat along the Front Range is becoming increasingly fragmented.
Yet few agencies that deal with wildlife seem inclined to develop a long-range management plan for prairie dogs, preferring an exterminate-as-needed approach. Both Denver Parks and Recreation and the Stapleton Development Corporation have drafted detailed management plans but failed to fully implement them. The disparity between what was conceived on paper and the emerging reality is particularly acute in Stapleton, which promised its residents extensive open space and natural areas and now is redefining a notion of "natural" that may be mostly devoid of one of the neighborhood's most industrious natives.
Once park land is acquired and developed on the Denver side of Stapleton, it's turned over to Parks and Recreation for management. But Ashley DeLaup, a former wildlife ecologist with the department, says Parks and Recreation has "definitely gone in a different direction" since her position was eliminated two years ago. Mayor Michael Hancock and new parks chief Lauri Dannemiller have pushed for a controversial land swap that would give the Denver Public Schools 11.5 acres of previously designated open space in the Cherry Creek corridor for development in exchange for an administrative building in central Denver; Hancock has referred to the Hentzell Park natural area as "blighted" and overrun with prairie dogs. Parks and Recreation has also mounted an effort to "manage" prairie dogs in emerging park areas of Stapleton by euthanizing them.
The prairie-dog plan that DeLaup worked on called for a range of non-lethal solutions, including barriers and vegetation management, to keep colonies from spreading. "In Stapleton, I think we were doing a pretty good job," she says. "It's one of the more successful ecosystems in Denver. But getting rid of prairie dogs will impact the ecosystem in a negative fashion.
"The view now seems to be, 'Let's have native plant gardens. This isn't really a prairie; we're just going to make it look like one.' But the animals are going to be there, and if we don't consider that, we're going to have increased conflicts."
A fierce and abiding hatred of prairie dogs is so deeply ingrained in some areas of Colorado that it could almost be considered a state tradition. Ranchers have always loathed them, calling them varmints and vermin, and that was good enough for state lawmakers, who obligingly enacted legislation calling for their mass extermination. One 1927 law declares a state of emergency "so urgent that public necessity demands that prompt, efficacious, and summary action be taken under the police power of the state to control, suppress and eradicate such rodents in the areas infested by them."
Colorado's Department of Agriculture still labels prairie dogs as "destructive rodent pests." Yet over time, a body of research has piled up that supports a reappraisal of the prairie dog, a rodent that's more closely related to a squirrel than a rat. They're a staple of the diet of coyotes, foxes, hawks, eagles and the endangered black-footed ferret. Their digging can tear up vegetation and has been described (unfairly, activists insist) as a hazard to livestock, but it also provides nesting areas for the mountain plover and the burrowing owl.
Prairie dogs also have one of the most sophisticated languages in the animal kingdom. Their impressive array of distinct barks and yips comprise a detailed warning system to alert others to the arrival of different predators or other threats. "Prairie dogs are amazing," says Taylor Jones, endangered-species advocate for WildEarth Guardians. "They're like us. They talk, they yell, they like to be close to their families. They like to build houses in the same places we do. And they do ridiculous things."
Their ecological value is recognized in the state's comprehensive wildlife-conservation strategy, which describes all three species of prairie dogs found in Colorado as "species of greatest conservation need." The need stems from the inexorable decimation of the prairie dog's historic range, which once stretched over more than a hundred million acres from Canada to Mexico. They can now be found in greatly diminished pockets of habitat in twelve western and Midwestern states; one recent study of 384 habitat fragments remaining in south Denver found that a third of them had been wiped out by development in just five years.
"Just imagine a bunch of polka dots across those states," says Jones, who issues an annual "Report From the Burrow," grading state and federal prairie-dog conservation efforts. "A lot of them are really isolated and far away from each other. Compared to what they used to be, there's been a 98 or 99 percent reduction in their population."
Statewide, Colorado doesn't come off too badly in Jones's rating system, earning a C+ this year; most states didn't get a passing grade. "Colorado is actually one of the better states, and that's kind of a sad commentary on how the prairie dog is faring," Jones says. "It's difficult when there aren't any meaningful restrictions on poisoning them. One developer can make the decision to put poison all over the landscape and kill wildlife."
A reason that's often given for eradication efforts is the supposed "health risk" involved in having colonies close to urban development, since prairie dogs are highly susceptible to plague. It's one of the justifications, along with preventing damage to surrounding vegetation, offered by park officials for a recent extermination campaign in the area of Stapleton's Westerly Creek Park. "When you have a trail that goes to a prairie-dog colony," says Denver Parks and Recreation deputy director Scott Gilmore, "and you've got people walking their dogs and children — my fear is a child or dog picking up a dead prairie dog and someone gets bubonic plague."
But prairie-dog advocates say the plague concerns are overblown. The most common transmissions of plague from animals to humans involve hunters not taking proper precautions while skinning small game. Plague conveyed to people by prairie dogs is rare, and flea-powder dustings of colonies have proven effective in preventing outbreaks. Parks and Recreation's own draft management plan for prairie dogs notes that plague hasn't been seen in Denver's prairie-dog population since 1982.
"Prairie dogs don't have any immunity to plague, so they're not a carrier," says Lindsey Sterling-Krank, director of the Boulder-based Prairie Dog Coalition. "They experience almost a hundred percent mortality rate, sometimes within 24 hours. They're more an indicator that plague is in the area. But plague is all around us, in any number of species."
Longtime prairie-dog activist Danny Rifkin has seen the plague card played frequently in public debates over prairie dogs. "There's a campaign of hatred and misinformation out there," he says. "From what I've seen over the last twenty years, prairie dogs are being pushed out to little patches by the roadside. If we don't do something, they're going to disappear from our landscape in the next ten or fifteen years."
Rifkin came to Denver in the 1980s, when it was still possible to see prairie dogs cavorting on stretches of empty land along Parker Road. He got involved in a doomed battle to save one large colony that led to multiple presentations before snickering Arapahoe County commissioners. "I watched a Texas corporation level the place," he recalls somberly. "It just turned into another apartment complex. I saw them die. Then I saw it was happening all over."
One of the greatest obstacles to moving urban colonies out of the path of development is a 1999 law, Senate Bill 99-111, which requires that any relocation of prairie dogs from one county to another be approved by the county commissioners of the receiving area — even if the transfer is between private landowners. In practice, that approval is almost impossible to obtain; most of the Front Range counties have no place to put their own problem colonies, let alone someone else's, and rural commissioners fear the wrath of farming and livestock interests. But Rifkin is encouraged by recent efforts made by one of the great prairie-dog slayers in the state: the Regional Transportation District.
"RTD is the only organization that's actually stepped up and relocated a couple of small colonies," he says.
Like the Colorado Department of Transportation, RTD has a policy in place designed to minimize the impact of its construction projects on prairie dogs. It involves avoiding disturbance of active colonies whenever feasible — but as the light-rail lines to DIA and Golden and along I-225 continue to develop, crews have encountered numerous dog towns. The next alternative is to seek options for live relocation, but that's proven to be an even more formidable challenge.
"It's difficult to move prairie dogs in Colorado," notes RTD FasTracks spokesman Kevin Flynn, who describes the 1999 law as "the Mann Act for prairie dogs — you can't transport them across county lines for immoral purposes."
Yet the agency has managed two in-county relocations in recent months. A 108-dog colony sitting on what will become the Peoria station for the airport line was moved to twelve acres of land that RTD already owns near Barr Lake. "There's an eagle refuge out there," Flynn says. "I told the wildlife advocates we worked with that this would be like Country Buffet for the eagles. Their response was, 'That's the way it's supposed to be.'"
The second move was more complicated. A contractor charged with relocating a 150-dog colony near the Iliff station on the I-225 line looked into fifty prospective transfer sites before reaching an arrangement with the State Land Board to place them on land owned by the board in the former Lowry Bombing and Gunnery Range. News accounts of the deal suggested that the critters were being dumped near ranches and homes, prompting howls of protest from nearby residents.
But they got it wrong, Flynn says. "People who don't like prairie dogs at all object to anybody moving them anywhere," he adds. "This site is not near any homes, ranches or farms. It's a site designated for shortgrass prairie ecosystem restoration."
Despite these modest successes, RTD has been unable to line up more relocation sites for colonies found at other future FasTracks stations. For the most part, the agency has had to rely on its third option — trapping prairie dogs, euthanizing them with carbon dioxide, and donating their stubby little carcasses as chow to a raptor-recovery program.
"We have killed substantially more than we have relocated," Flynn acknowledges. "We have killed hundreds, if not thousands, at this stage. That's just the way the system works right now."
Three months ago, Patricia Olson assembled a panel of wildlife experts at Colorado State University to explore the possibility of developing a prairie-dog park in Stapleton, possibly as part of the "natural park" that was supposed to be built right around the corner from her home. The idea was to come up with a pilot project that could demonstrate innovative, non-lethal techniques for managing a small urban colony, while also providing an educational opportunity for the children of Stapleton to learn something about the wildlife in their own back yards.
The panel, which included several of the state's leading researchers on prairie dogs and their ecosystem, had a lot of difficult issues to consider. Because the space they have to operate in is so limited, urban colonies tend to be much denser than those in unfragmented habitat, containing from two to five times more rodents per acre than you would find in a rural environment. The effect on the landscape can be dramatic: a rapid denuding of vegetation and creation of a moonscape pockmarked by burrows. That, in turn, leads to erosion of topsoil, dust problems and conditions that invite invasive plant species such as bindweed. ("They take bindweed and make it into little bales and take it into their burrows for the winter," Olson notes.) When the vegetation is all gone, the prairie dogs tend to spread out farther, in search of greener pastures they can transform into Mars.
It's a daunting situation, but hardly an unmanageable one, the experts agreed. Vegetation could be surveyed, monitored and supplemented, if necessary. While the existing plants would definitely take a hit, irrigation could help shore up native species and minimize the dust problem. Proper landscaping and barriers, including the use of ornamental tall grasses at the site's boundary, would help discourage migration; prairie dogs like to erect burrows in short-cropped areas so they have clear sightlines — which is why golf courses and ballfields are so alluring to them.
Population control could be achieved through the use of raptor perches — tall poles that invite hawks and eagles to come check out the buffet — or even, if necessary, the use of a contraceptive that has to be injected but lasts two years. There are also observation decks and playground equipment available that allow children to observe prairie dogs without having any direct exposure to them.
Encouraged by the discussion, Olson prepared a paper summarizing the panel's recommendations. "We've got these twenty-acre plots left all over the Front Range," she says. "We could manage these small areas and significantly help the overall population."
She presented the paper to Forest City, Denver Parks and Recreation and other groups involved in Stapleton's open-space planning, hoping it would receive serious consideration. After all, the Stapleton development plan, known as the "Green Book" — published in 1995, on recycled paper with soy-based inks — had been a kind of environmental manifesto, promising a "rich and diverse" open-space system that would include "extensive natural areas that support significant wildlife and allow the restoration of native plant and animal communities that have been displaced and eliminated. This focus represents a return to Denver's natural heritage as a city established on the prairie." And was there a more displaced species, a more valuable source of benefit to 150 other types of plants and animals, than the prairie dog?
But so far, no agency has adopted any part of Olson's proposal. "I can't get anyone to listen," she says. "They say, 'That's not part of our strategy.'"
Forest City spokesman Gleason concedes that saving the prairie dog is pretty low on the to-do list of what has been Denver's biggest and most challenging infill project. "There will continue to be prairie-dog habitat at Stapleton," he says. "The question is where and if we can support additional prairie dogs. We're trying to do a lot of things that we think are part of the original vision for Stapleton: affordable housing, good quality schools, things of that sort. Prairie dogs are not one of the highest priorities."
While he has heard complaints from activists about the exterminations, Gleason says he also gets calls from "people who are out running the trails and saying the prairie dogs are destroying the area."
There's clearly been a shift at the corporate level from the vision of a reclaimed natural area espoused in the Green Book. Jonathan Ratner, Forest City's "vice president of sustainability initiatives," is on the board of directors of the Humane Society of the United States, the parent organization of the Prairie Dog Coalition — but his company now takes the position that killing off prairie dogs is the best way to protect its substantial investment in well-groomed, recreation-oriented open space. The company has already shelled out $27 million to create more than 800 acres of regional open space; a total of more than 1,100 acres of open space is projected at buildout.
In a recent letter to Representative Diana DeGette regarding Olson's proposal, a Forest City official explained that the original Stapleton prairie-dog management plan "was often found to be unworkable because prairie dog habitat is generally not compatible with the type of open space that can be enjoyed by humans...We believe prairie dog habitat preservation is best suited for the 15,000 acres of the Rocky Mountain Arsenal Wildlife Refuge, which is immediately adjacent to Stapleton on our northern and northeastern boundaries."
Pam Wanek, a Prairie Dog Coalition advisory boardmember, says that Forest City has reneged on the design of Stapleton as portrayed in the Green Book. Recent illustrations of what the buildout will look like at its north end indicate residential construction right up to the border of the Rocky Mountain Arsenal, where a green buffer zone was previously indicated. "That would have been the place to have their Stapleton prairie dogs," she says. "As far as I know, not any of that piece has been purchased for open space, and Stapleton isn't making any commitment to have prairie dogs out there."
Gleason responds that Forest City remains committed to the same total figure of 1,116 acres of "trunk open space" touted in the original plan. The changes simply reflect "a more beneficial arrangement" at the yet-to-be-built north end to allow more access to open space by residents, he says.
The developer's argument that it doesn't need to preserve prairie dogs is a retreat from its promises, Wanek contends. "If you want to protect your wildlife, it has to be done locally," she says. "That's where the laws are."
One place in Stapleton that prairie dogs are likely to survive is the Bluff Lake Nature Center, a 123-acre wildlife refuge that was once a designated airport crash zone. Billed as an "outdoor classroom" and visited by thousands of schoolkids each year, the center offers examples of a variety of riparian, wetlands, woodland and prairie habitats — and a prairie-dog colony eager to expand its range into other habitats.
"If we didn't manage them, they would destroy the viability of the other habitats," says Bluff Lake executive director Jeff Lamontagne. But to date, Lamontagne explains, that management has consisted largely of devising barriers and filling in outlying burrows to encourage them to stay in their own area: "We'll do what we have to do to satisfy our obligations, but we believe there are ways to do it on our site without thinning their ranks."
Elsewhere, the prairie dogs have not been welcomed. They've been blamed for an estimated $100,000 in damage to a greenbelt buffer between I-70 and the Northfield shopping center. And their presence in Stapleton's Westerly Creek area has prompted trapping and euthanizing by Denver Parks and Recreation, in an effort to protect the native plantings in the area and the manicured Central Park just west of the creek.
DPR deputy director Gilmore points out that he inherited the problem from the developer, after the completed park area was turned over to Denver to manage. "It was designed as a naturalized area," he says. "I won't say 'natural area' — it's more of an open-space area with native plants. Between Forest City and us, we've invested hundreds of thousands of dollars in creating these open-space areas, and prairie dogs have moved in and clear-cut everything."
Gilmore has a degree in wildlife biology and is understandably touchy about the chemical-warfare program. "I haven't made any decisions lightly," he says. "I love prairie dogs as much as anyone else. But we're trying to protect the landscape that we created. We couldn't move them; it's not easy to relocate anywhere in the state. We couldn't leave them, because they were eating everything. We decided we could trap them and euthanize them on site."
Although Parks and Recreation has been relying on carbon monoxide for the Westerly Creek colony, Gilmore won't rule out the use of aluminum phosphide, which he says is "more efficient" in some situations. But he also plans to use more creative solutions on the south end of the open-space area, including raptor poles at the edge of the Aurora-Denver border there.
But DeLaup, the city's former wildlife ecologist, anticipates that it's going to be difficult to keep prairie dogs out of Westerly Creek, which connects with the Sand Creek Regional Greenway. "The prairie dogs have all sorts of pathways back into the open space," she notes. "Unless they concrete it over, they're going to have the animals back again."
If the deal to trade the Hentzell Park natural area to Denver Public Schools goes through, DeLaup predicts removal problems there, too. "That ecosystem is not as far along as Westerly Creek, but it has good connectivity," she says. "It's going to be a superhighway for a lot of wildlife. Some of our best historic prairie in the city of Denver is in that area. But with new construction, you're breaking up the old pathways and increasing wildlife conflict."
If the engineers of open space can effectively remove prairie dogs from the scene, DeLaup expects that other wildlife will disappear, too, if they can't find other food sources. When she was fielding calls about street-roaming coyotes terrorizing pets a few years ago, the area registering the fewest complaints was around Hentzell Park — where, presumably, the coyotes were feasting on prairie dogs instead of cats.
RTD's Flynn recalls how a transit crew doing utility relocation near Havana and Smith Road enjoyed watching a golden eagle that perched in a cottonwood there. As part of its work, the crew euthanized a prairie-dog colony that was in the way. Once the colony was gone, they never saw the eagle again.
"Citizens in metro Denver place a high value on wildlife in general," Flynn notes. "When you see a fox in your yard or a hawk circling overhead, it reminds you of what you value about Colorado. But the reason they're circling is that they've seen a prairie dog in the area."
Prairie Dog Coalition director Sterling-Krank says it will take a fight on several fronts to change the prairie dog's dismal status, from amendments to the 1999 law to education to economic incentives for developers to relocate them. "We need some kind of regional preserves," she says. "We don't have any synergy in Colorado for prairie-dog ecosystem protection — and without it, we're looking at this whole wave of secondary extinction. It's not just about the prairie dogs. It's about the burrowing owls, the ferruginous hawks, the black-footed ferrets, and all these other species that depend on the prairie dogs for survival. They're kind of like the canary in the coal mine."
Unlike canaries, though, prairie dogs seem drawn to danger and adventure, to the green zone of death. Stapleton may not love them, but they love Stapleton. After the long and painful campaign along Westerly Creek, after the trapping and gassing had concluded, park workers began breaking out equipment, spreading straw and working on rehabilitating the area. Then mounds arose and holes erupted in the work area, manned by yipping sentries.
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