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Of Mice and Men

Somewhere beneath the tall grasses of Rocky Flats, not far from the small streams that wind through the buffer zone surrounding the former nuclear-weapons plant, a Preble's meadow jumping mouse is taking a well-deserved nap. Its fate is being decided elsewhere.

The mouse--which weighs less than an ounce, sports a six-inch tail that accounts for more than half its length and boasts oversized hind legs suitable for leaping several feet--hibernates from October until early May. You would, too, if you had the Preble's problems. During the summer months, the mouse scampers about at night, dodging predators, foraging for grass seeds, berries and insects, and caring for two or three litters. The final weeks before it descends into its leaf-lined burrow are devoted to a feeding frenzy, building up fat reserves for the winter.

The Preble's work is never done, it seems. Even its seven-month snooze isn't as restful as it once was, what with all the biologists busily studying its behavior, trying to identify its habitat, and plotting next summer's trapping season--a process that has intensified since last March, when the U.S. Fish and Wildlife Service (USFWS) formally proposed listing the Preble's as an endangered species. While the mouse sleeps, its mere presence at Rocky Flats and a handful of other sites in Colorado and Wyoming is shaking up a host of development plans and public works projects.

The mouse has alarmed ranchers, annoyed county commissioners and frustrated open-space planners. It has delayed a $35 million pipeline project in El Paso County and drastically altered a private company's plans to mine gravel at Rocky Flats. It has raised questions about a new highway interchange north of Colorado Springs and a proposed 18,000-acre development in Jefferson County. It has sparked at least three lawsuits filed by environmental groups that have accused the federal government of not doing enough to protect the mouse. And it has cost taxpayers plenty, including a recent $400,000 congressional appropriation to develop a plan to keep the mouse from being an even greater threat to future development.

All this fuss over a critter most people have never seen strikes some observers as absurd. "These little rodents have no place in the ecosystem of any benefit," wrote Wayne Bonham, president of Wyoming's Pole Mountain Cattlemen's Association, in a letter of protest to the USFWS a few weeks ago. "They are of no benefit to the human being. Why spend the taxpayers' money and the general public's time for something that is so meaningless?"

The mouse's defenders, though, say the sudden wave of attention is long overdue; after all, look at what humans have done to the mouse. The Preble's subspecies of jumping mouse is found principally along a narrow band of heavily vegetated rivers, creeks and other drainages--known as riparian corridors--on the east side of the Rockies from Cheyenne to Colorado Springs, an area that's been all but devoured by the past two decades of urban sprawl.

"They like a lot of structure," says mammalogist Carron Meaney. "Not just plain grasses, but a mixture of dense shrubs, coyote willow and overhanging cottonwoods. Unfortunately, the areas they like are also extremely popular with people."

Exact numbers are hard to come by, but those who've studied the mouse believe that massive urban development has devastated the Preble's habitat and reduced its population to a few hundred, scattered among isolated sites in half a dozen Colorado counties and two sites in southern Wyoming. Significantly, the healthiest known colonies are at the U.S. Air Force Academy and Rocky Flats--two federal properties that have been largely insulated from development pressures since the 1950s.

"This is one of the rarest, most imperiled, unprotected small mammals in the United States," says Jasper Carlton, executive director of the Biodiversity Legal Foundation, a Boulder-based nonprofit that sued the USFWS to compel the agency to declare the mouse an endangered-species candidate. "We've concluded that it's more endangered than the black-footed ferret was when they listed it, more endangered than 90 percent of the species that have been listed under the Endangered Species Act. The populations we know of are so small that they're all threatened."

The USFWS has until next spring to decide whether to add the mouse to the endangered species list. The final decision will be made by the agency's new director, Jamie Rappaport Clark. Last year Clark, then an assistant director of ecological services, filed an affidavit in response to the Biodiversity Legal Foundation's lawsuit, declaring that the Preble's jumping mouse "does not face an imminent risk of extinction." This year her agency has announced that the mouse "is in danger of extinction throughout all or a significant portion of its range."

Fish and Wildlife's official ambivalence is indicative of the divided opinion about the mouse in regulatory and scientific circles. Mouse researchers like Meaney say they still don't know enough about the shy, nocturnal creature's behavior, habitat needs and reproductive cycle to accurately gauge its chances for survival, nor can they make reliable projections of the size of a given population based on the few mice that have been trapped at various sites.  

"We've had more people out looking for this thing in the last five years than in all its history before that," says Peter Plage, a biologist in the USFWS Colorado field office who's been coordinating the agency's efforts on behalf of the mouse. "But there's a lot we still don't know."

Equally uncertain is the effect that listing the mouse as endangered might have on the booming economy of the Front Range. The USFWS proposal describes a complex array of potential threats to the rodent and its habitat, from grazing, mining and housing developments to water diversions, bike trails, Rocky Flats cleanup efforts--even "free-ranging domestic cats." Endangered-species protection for the mouse could lead to considerable delays and costly modifications for a wide range of projects, particularly those in which federal lands or federal permits are involved.

Carlton says that concerns about the mouse's potential to halt development in some areas have been greatly exaggerated. "You get a lot of fear-mongering going on," he says. "People make statements like, 'If we list this species, it will be the end of the economic way of life here in Colorado.' The fact is, no one is in a position to know what impact the listing of the Preble's will have on local economic interests."

Some people aren't waiting to find out. For the past few months the Colorado Department of Natural Resources has been assembling a coalition of development, government and environmental interests to come up with a conservation plan that could keep the mouse off the endangered species list--or, at the very least, maintain some local control over efforts to restore the riparian areas and minimize the problems the listing would present to local officials and private landowners. Boosters of the state task force claim it's an innovative, constructive approach to dealing with an extremely cumbersome piece of federal legislation; skeptics such as Carlton view the process as an attempted end-run around the requirements of the Endangered Species Act that could lead to more litigation.

"It's illegal to substitute a conservation agreement for the listing of a species that's already biologically threatened and endangered," Carlton says. "There's no way they can remove all of the threats in six months and get a program under way that shows increasing restoration of habitat. If they try it, we will litigate, and we will prevail."

In many ways, the battle over the jumping mouse is shaping up to be a classic tug-of-war among environmentalists, developers, agriculture, industry, and local and federal officials. But more than most other endangered-species controversies, the mouse mess is also a window into how decades of unfettered growth have irrevocably changed the natural landscape in eastern Colorado.

Eighty percent of the state's 3.9 million people now live in 4 percent of its land area--the Front Range urban corridor--with a million more inhabitants expected by 2020. The human invasion has had a profound effect not only on the mouse but on the waterways and surrounding vegetation upon which a great deal of other native wildlife depends--a system as fragile and complex, in its own way, as the Everglades or the Serengeti. The mouse's most ardent defenders say they're crusading not just for a species but for a threatened ecosystem.

"This is not about just a little mouse," Carlton says. "This is about the destruction of riparian corridors from Cheyenne to Colorado Springs."

Named after naturalist A.E. Preble, who first discovered the rodent in Larimer County in 1895, the Preble's meadow jumping mouse remains an object of some mystery and confusion among biologists.

Some have questioned whether the mouse is a legitimate subspecies; until recently, the best way of distinguishing it from other western jumping mice involved measuring the skulls of dead mice. A California laboratory is now conducting DNA analysis of small samples of ear tissue, explains USFWS biologist Plage, "to sort out genetically what these critters are and if there have been some mistakes in historical capture records."

Researchers do, however, agree on one thing. "They're really an unusual rodent," says Carron Meaney, who's working with the Colorado Division of Wildlife on field surveys of the mouse. "They're very long-lived. Most mice live less than a year, but this one hibernates and presumably is around the next year. They jump. They swim. I find them very interesting-looking and attractive."

With its kangaroo-like hind legs and flaps on its nostrils that appear to allow it to swim easily, the mouse seems magnificently adapted to elude pursuers by air and by water. (Even its long, sparsely haired tail apparently aids its jumping; a Preble's without a tail, Meaney says, "couldn't jump properly and would just kind of corkscrew around.") Yet the Preble's population along the Front Range has probably never been abundant, and in recent years, despite more vigorous trapping efforts than ever before, the mouse appears to have all but vanished from several areas where it had previously been known to reside.  

Wildlife ecologist Tom Ryon has been studying the Preble's population at Rocky Flats since 1991; he's also conducted a search for the mouse in other areas of its historic range, investigating nine known sites in six counties. Trapping failed to produce any mice, and Ryon concluded that the Preble's no longer inhabits any of the sites.

"Some of them were just developed so much that there wasn't even a need to trap," says Ryon, who works for PTI, a subcontractor involved in the cleanup at Rocky Flats. "One site, for example, was close to the Westminster Mall. Anywhere in that area, there's just no hope of native vegetation any more. Other areas have been totally disturbed and grown back, but they've since been isolated upstream and downstream, so that corridor for the mouse is missing."

The apparent decline in population sent alarm bells ringing throughout the environmental community and brought the Biodiversity Legal Foundation into the fray. In 1994 the BLF, which conducts its own scientific research and has successfully challenged the government's actions on endangered-species issues in several states, filed a petition with the USFWS to list the Preble's as endangered throughout its range. The agency had considered the mouse as a "potential candidate species" as far back as 1985; but when it failed to act on the petition in the required time frame, citing a lack of resources and inadequate data on the threats to the mouse, the BLF filed suit in federal court.

This wasn't the first time the BLF had gone to court with the USFWS over a Colorado species. A similar battle had erupted over ladies' tresses, a rare orchid found in Jefferson, Denver and Boulder counties. The orchid is now listed as endangered, and recovery efforts are under way, "but that also required a considerable push-and-shove match," the BLF's Carlton says. "Everybody from Coors on down protested that."

Carlton describes the Preble's jumping mouse as "the proverbial canary in the coal mine. It's a wake-up call," he explains. "We defend uncharismatic species. They may not be popular, but they're indicator species for the health of ecosystems. For example, almost every native subspecies of cutthroat trout in Colorado is biologically threatened or endangered. Almost all of our freshwater mollusks are in serious trouble. Now it's the small rodents and plants. These are all associated with the quality of water systems; and what happens to water eventually happens to human beings."

The USFWS finally agreed to propose listing the mouse last spring--and paid the BLF's attorneys' fees in the bargain--but Carlton is far from satisfied. "The Fish and Wildlife Service has intentionally dragged its feet in protecting this little mouse," he fumes. "Part of my agitation is that this is not a gray-area case. All the data was there, but they made us go through two court cases, and the amount of controversy and antagonism just increases. We have multiple species that are going down the drain in riparian corridors. If we're going to recover them, we've got to find a way to work together."

Peter Plage of the USFWS state office says his agency is eager to work with a variety of interests to save the mouse. Still, the proposed listing has generated a flurry of negative comments from folks who don't share Carlton's dire view of the situation.

"We do get, especially from Wyoming, requests to give them a worst-case scenario," Plage says. "A farmer says, 'Okay, if I'm out here haying my field and I kill one of these mice, are you going to arrest me?'--that kind of stuff. We've said, 'Look, we don't have the enforcement people or the interest to disrupt ongoing agricultural practices. But if someone was going to bulldoze an entire mouse habitat, we would look closely at that.'"

To date the agency has held three public hearings and received approximately forty letters about the proposed listing; a second comment period begins next month. Many of the letters have come from ranchers and chamber-of-commerce types questioning the need to protect the mouse. "Please send me a scientific study of these poor, cowering beasties," wrote one skeptic. "If it's like the rest of the varmints I have, you can't get rid of them by any means."  

Predictably, some of the protesters have accused groups like the BLF of having their own radical agenda in the matter. "It is very likely that the environmental organizations suing to get this mouse on the endangered species list...are doing so solely to stop economic development along the Front Range," wrote Raymond Berry, president of the Pikes Peak Chapter of People for the West!

Others, including several county officials, have argued that the federal government still doesn't know enough about the mouse or its "purported" population decline to declare it endangered. They point to the sketchiness of historic records, the lack of hard data on present populations and the impossibility of determining if the mice have entirely disappeared from an area simply because none were trapped during a particular sequence of "trapnights" (one trap set for one night equals one trapnight). "There is a severe lack of scientific data to support the proposal," wrote Ron Micheli, director of the Wyoming Department of Agriculture.

Researchers concede that they don't have the long-term studies yet to chart the population decline, but they insist that such a decline is obvious, given the rapid disappearance of the mouse's available habitat. "We don't have solid numbers on populations," says Plage, "but secure populations are more important than absolute numbers. If you have fifty acres of good habitat, maybe there's a hundred mice, but that doesn't mean it's secure--you could have bad weather, disease, whatever, and find nothing there the next year. Typically, small-mammal populations swing up and down dramatically."

Recently, though, the Preble's has been turning up in places it hadn't been found before. Over the past two summers Carron Meaney surveyed 27 likely habitat areas in Colorado and found mice in eleven of them, including two state wildlife areas in Larimer County; trapping in Weld and Elbert counties yielded one individual in each county. The Preble's has also surfaced on Boulder Open Space lands, along East Plum Creek in Douglas County, on Jefferson County Open Space land near the mouth of Coal Creek Canyon, along Monument Creek and various tributaries in El Paso County--and even under a highway overpass.

Meaney cautions against reading too much into one-time survey results. Virtually all of the new finds are small in number--for example, in one study, only 23 mice were captured in Boulder over 17,800 trapnights--and may simply have been overlooked before.

"I can't say I'm surprised," she says. "I believe the reason they weren't being found before is that no one was trapping for them. Small mammals, like mice--you can't know if they're there unless you trap."

The crucial question, Meaney adds, is how stable the "new" populations are. "We're pleased to find them a few years in a row at Rocky Flats and the Air Force Academy, but there are still pressures on adjacent lands," she notes. "In a sense, they're living on little postage stamps of the landscape."

PTI's Ryon agrees. "Sure, there have been some more sites that have been discovered," he says. "But how many of those are open space, how many are federal lands, how many are private? What's the level of comfort that they are going to be there in the future?"

Last summer Ryon documented the movement of two mice, a male and a female, who traveled over a mile in two weeks along Woman Creek at Rocky Flats. He believes such mobility over high-quality habitat may be a key to the mouse's survival. But the surviving populations are largely isolated from one another, cut off from any genetic interchange by the sprawling Denver metro area and surrounding cities. Separating them are a procession of shopping malls and housing tracts, dried-up creekbeds ravaged by grazing and mining and endless miles of asphalt.

Tanya Schenk, a research scientist with the Colorado Division of Wildlife, says it will require in-depth population studies over several years to get a complete picture of what the Preble's is up against. "We need to get a handle on the movement of the mice, just to see how big their habitat requirements are," she says. "We also need to find out where they are reproducing and surviving the best. Those are the two key things."

For now the mouse's best and final havens appear to be the Air Force Academy, Rocky Flats, and Boulder's open-space lands. There's a peculiar irony in a former bomb plant providing sanctuary to a mouse, but an increasing number of native flora and fauna have come to depend on such places for their survival; once heavily grazed, the Rocky Flats buffer zone now boasts one of only twenty xeric tall-grass prairies left in the world.

Yet even these relatively unmolested sites aren't as secure as they once were. Development to the east of the Air Force Academy is progressing at an ominous clip. The Sierra Club is currently suing the U.S. Department of Energy, claiming that the feds have failed to protect the mouse from a proposed expansion of gravel-mining operations at Rocky Flats. As for Boulder's wide-open spaces, some observers believe that creekside bike trails and jogger encroachment may not be in the best interests of the mouse. Meaney is monitoring the situation but says it's too early to draw any conclusions.  

"If we could stabilize everything," says Plage, "with no further losses to any of the populations, the mouse probably wouldn't need to be listed. But the Endangered Species Act applies not only to the current status, but also to the trend or threat--and the threat is pretty obvious here."

Two years ago Governor Roy Romer and Secretary of the Interior Bruce Babbitt announced a historic agreement that encourages the state of Colorado to take the lead in developing conservation programs that could keep threatened plants and wildlife from winding up on the endangered-species list. The pact, the first of its kind, basically gives the state more power to identify and manage imperiled critters without the heavy regulatory burden of the Endangered Species Act.

The agreement is part of a larger strategy by the Clinton administration to push what it calls "creative solutions" to endangered-species battles through the use of habitat conservation plans, or HCPs. One provision of the act allows the feds to issue an "incidental take permit" to states, local governments or private landowners that have developed a suitable HCP; for example, a developer might be permitted to trap or kill a rare or even officially endangered species in a given area in exchange for providing sufficient habitat somewhere else. When Bill Clinton moved into the White House in 1993, there were only fourteen HCPs in place; now there are close to 200, with another 200 under consideration.

Possibly because so many of its rarest species are found primarily on federal lands, such as national forests, Colorado has no HCPs yet. The Preble's meadow jumping mouse may be the first.

For the past several months, a state-run task force of public and private interests has been working to hammer out a conservation plan that could keep the mouse off the list entirely--or, at the very least, minimize the hassle that various "stakeholders" will face if the mouse is declared endangered. The effort has been funded by a mix of private industry and state lottery funds, as well as a $400,000 congressional appropriation obtained by Representative David Skaggs.

"Time is of the essence in getting measures in place to protect the mouse," Skaggs said last month when he announced the funding coup. "Nobody wants an Endangered Species Act train wreck in the areas where Colorado's population is growing the most rapidly."

But the BLF's Carlton views the collaborative planning process as an attempt to derail the protection the mouse would have under federal control. While he supports the notion of offering "positive incentives for private landowners to work for the protection of our imperiled wildlife," he also worries that political interference could taint the scientific process of determining what the mouse needs to survive.

"This is clearly an attempt to avoid the listing," he says. "Recovery planning takes years of conscientious, peer-reviewed work. I think they're trying to avoid a legal mandate to recover riparian corridors because they think there's going to be too much restraint on future development."

Colorado Department of Natural Resources assistant director Doug Robotham, who's leading the task force, says the group is seeking the best possible alternative for the mouse and for affected landowners. "We're trying to strike a balance here," he says. "The goal is as much to conserve the mouse and its habitat throughout its entire range as it is to create a process that is less onerous for people who need [federal] permits to engage in their livelihoods."

Robotham adds that the state's unique agreement with the feds presents an opportunity for Colorado to protect its wildlife without resorting to "the triage of protective measures embodied in the Endangered Species Act." Coming up with a conservation plan for the mouse could be the first step in a program that could eventually encompass a number of other species that are not yet considered endangered but whose populations have been dropping dramatically, such as the lark bunting, the official state bird.

But Carlton contends that the state's task force amounts to little more than triage work itself, in an effort to head off the pending listing of the mouse. "They're not putting money into species that are not yet biologically threatened and endangered," he says. "They're only spending money to try to prevent species from being listed so that there is not an enforceable, accountable recovery plan."  

The threat of listing does seem to be driving much of the sudden attention the Preble's is getting. Interest in the state's task force took off after the mouse officially became an endangered-species candidate last March.

"That really served to light a fire under this planning effort," Robotham says. "Our little working group went from ten or twelve people to about sixty, and there are quite a few more than need to be brought into it."

The current group includes a host of local and state officials and wildlife experts, environmental groups such as the Sierra Club and the Nature Conservancy, and a contingent of development interests--representatives of the Colorado Rock Products Association, the Colorado Contractors Association, the Colorado Water Congress, and so on.

"It's a pretty diverse group of stakeholders," says Judy Sheppard, the Division of Wildlife's program manager for endangered birds and mammals. "A lot of them feel that if the mouse is listed, their hands will be tied--that the federal government will come down on them and they'll have a difficult time getting things done."

The private-sector stakeholders already have one example of what could be in store for them in the case of Western Aggregates, which is mining gravel on the eastern edge of the Rocky Flats buffer zone. (Although the land is owned by the federal government, the mineral rights are controlled by private parties.) The company had to go through a gauntlet of local and federal agencies to get its plan approved, and concerns about the mouse may severely limit any expansion of the mining.

"It's significantly affected our original mining plan," says Martin Jones, the company's vice president and general manager. "We had to give up a lot of reserves. We're mining only above the water table so as not to disrupt the groundwater flow to their habitat downslope." In addition, the company has agreed not to mine 400 acres out of the 1,000 acres originally proposed.

Jones notes that his company took a "conservative approach" and was able to work out an acceptable plan with the USFWS to protect the mouse. "I don't think it has affected that many projects yet," says Robotham, "but it certainly has the potential to affect a lot more if it's finally listed. The proposed rule was so broadly drafted that it's difficult to know."

Colorado Springs Utilities, which provides electricity, gas, water and wastewater service to booming El Paso County, ran into its own mouse problem last summer when the U.S. Army Corps of Engineers ordered work stopped on a $35 million pipeline project in order to survey areas where the line would have crossed possible Preble's habitat. The delay lasted only a few days.

"We didn't find the mouse there, which was fortunate for us," says John Fredell, senior environmental attorney for the company. "Had the mouse been found, we would have seen some major delays."

Fredell, who represents both the utility and Colorado Springs on the state task force, says the group may ask the USFWS to delay its decision on listing the mouse for another six months in order to give the state more time to come up with a conservation plan.

"Anything that's going to involve crossing a creek--new interceptors for wastewater lines, putting in paths for parks, whatever--it's going to be a more difficult process," he says. "There are a lot of details that haven't been worked out."

At the same time, Fredell says he's encouraged by what the task force has been able to accomplish so far. "You hear the spotted owl horror stories, the stories about projects being held up forever and the huge expense," he says. "We've come a long ways from the first few days after the proposed listing, when people were talking about going in and amending the Endangered Species Act. I think we've got a real opportunity here to set up a national blueprint for working through these kinds of things."

Biologists and local officials are also pleading for more time to come to grips with the mouse situation. However, the mouse may not have much time left. Jasper Carlton concedes that the Endangered Species Act "has plenty of club, but it doesn't have enough honey"--but he insists the act will provide more solid protection for the Preble's than further delays and interim conservation measures.

Still, even Carlton, who can sound like the voice of doom on the subject, says he's encouraged by the flurry of activity the proposed listing has generated.

"The riparian corridors on the eastern front of the Rockies are getting more management attention now than they've had for 25 years," he says. "We're not satisfied yet, but people are scampering to do some things. Hopefully, it's not just to keep the mouse from being listed."  

Two weeks ago a battery of industry interests sponsored a daylong conference in Northglenn on endangered-species issues. There was the usual grumbling from sportsmen, farmers and developers about federal heavy-handedness and regulatory overkill; the usual hand-wringing over how to balance competing recreational, commercial and governmental demands on dwindling resources; the usual cries for reform and gnashing of teeth over the outrageous costs involved in accommodating some small creature of the night that happens to be standing--or jumping--in the path of the next mega-mall.

Saving riparian corridors wasn't exactly the burning topic of the day. The notion of a threatened ecosystem may simply be too abstract to be grasped easily, particularly when its most endangered inhabitants are rodents that bear absolutely no resemblance to Mickey Mouse.

Wildlife's Judy Sheppard calls the Preble's jumping mouse "enigmatic mini-fauna," as opposed to "charismatic mega-fauna" like baby seals and grizzly bears. "They don't have big, round, dark eyes, they're not fuzzy and furry, and they're generally not anything we can identify with," she notes. "I talk to lots of college and high-school students wanting to do papers on wolves and grizzlies. The species we tend to identify with are at the top of the food chain."

In reality, Sheppard says, the pests and varmints at the bottom of the food chain may be more important in ecological terms than the big predators at the top of the heap. "Everything in the food web has a role," she says. "I don't think any of us are smart enough to know exactly what those roles are. But when you begin to take pieces out, you begin to weaken the web, and we don't know at what point we will cause it to collapse."

It's a familiar argument, the kind of thing one hears from time to time in the ongoing struggle over endangered species: Don't mess with Mother Nature. For all we know, that plant could contain a cure for cancer. They were here first.

Curiously, such statements seem to emerge in the public debate only at a point when the species at issue is already in the soup, when its habitat is all but gone and its very right to existence is being questioned--when, in short, it may already be too late.

The data still isn't in, but biologists suspect that the Preble's may still have a chance. For the moment, it has our attention. That's more than it's ever had before, and that may be what it needs to keep its chances for survival from spiraling downward--corkscrewing, like a mouse without a tail.


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