When the panel releases its report in late July, the conclusion proves surprisingly unequivocal: The Preble’s mouse is a distinct subspecies. "The available data are broadly consistent with the current taxonomic status of (the Preble’s mouse)," the report says. "No evidence has been presented that critically challenges that status." Even more stunning, the panelists have found that some of Ramey’s DNA samples show signs of contamination, which could account for the discrepancies between his study and King’s.

But even if Ramey’s data crumbled under scrutiny, his philosophical stand did not. "This doesn’t change anything," he says. The latest verdict, like all other decisions about subspecies designations, will remain arbitrary until scientists can agree on a definition of subspecies, he says. "What’s your listable entity? That’s the real question."

And Ramey’s philosophical arguments remain. At its core, the Preble’s dispute was never really about whether the mouse is a species or subspecies. Strip away the dueling datasets and clunky jargon and the dispute comes down to a philosophical question about what the Endangered Species Act should protect. When King and Ramey step back from the scientific debate, they both acknowledge this.

"It doesn’t matter to me whether it’s a subspecies or a distinct population segment," says King. "Any group within a taxa that appears to be reproductively isolated and heading down a different evolutionary trajectory from another group warrants conservation and attention, or at least consideration."

Not so fast, says Ramey. He argues that there’s a danger in overzealously applying caution to endangered species decisions. "If you set the bar too low, you completely dilute your effectiveness," he says. "We can make a conscious decision as a society that we want to give local populations of mice that have low levels of genetic differences the full protection of the Endangered Species Act. But ask yourself what it’s going to mean for the really unique things that you now don’t have the money to protect."

A priority system for applying the Endangered Species Act exists, but a 1988 General Accounting Office report criticized the Fish and Wildlife Service for not adhering to it. A recent study showed that things have hardly improved since then, with species that occur in urban areas receiving disproportionate funding at the expense of island species facing more urgent threats.

The genetic research, which many people have looked to for answers, only seems to add to the arbitrary approach. The Fish and Wildlife Service provides no guidelines on how genetic data should be used to make listing decisions. When Sylvia Fallon with the Natural Resources Defense Council recently reviewed more than 40 listing decisions, she discovered that the amount and type of genetic data that informed these decisions were all over the map. Studies that had used large amounts of genetic information tended to result in decisions that granted Endangered Species Act protection, while those that used less genetic data were more likely to end in verdicts that declined protection.

Ramey argues it’s time to change the way the Endangered Species Act is used. As it stands, the law is wielded far too often as a weapon against development at the expense of species that truly need protection, he says. Society shouldn’t need to find an endangered species in an area to save it: "If you want some open spaces that have lots of plants and animals in them, ultimately that’s the value, so let’s use that."

Other options do exist for protecting the habitat of the Preble’s mouse. Some Front Range communities collect funds to buy and protect open space, and private groups might also step in to pay for riparian habitat protection. But these strategies lack the teeth of the Endangered Species Act, and they cannot protect whole swaths at once.

And environmentalists counter that, until the laws change, the Endangered Species Act is the best tool they have for protecting ecosystems, something that not only benefits listed species, but everything else that uses an ecosystem, including humans. "This mouse is found only along healthy streamsides, so protecting it also means protecting our drinking water," says Erin Robertson, a staff biologist at the Center for Native Ecosystems. She acknowledges that reasons for protecting the Preble’s mouse extend beyond the little critter itself. The Preble’s mouse occurs on a habitat that’s quickly being developed: "That’s the bang for the buck on the mouse," she says.

The Fish and Wildlife Service will announce its decision on the delisting petition any day now — potentially before this issue arrives in your mailbox. But regardless of the outcome, the story doesn’t end here. While the panel’s report slams the door on the taxonomic arguments in the current delisting petition, those pushing to delist have a plan B at the ready. In March, Wyoming Attorney General Patrick Crank and his counterpart from Colorado, John Suthers, wrote to Fish and Wildlife Service Director Dale Hall, arguing that, subspecies or not, the mouse is more abundant than scientists first thought. "The Preble’s mouse is not threatened," they wrote, "it was just not well trapped in 1998" when it was given Endangered Species Act protection.

No doubt, if the Fish and Wildlife Service denies Wyoming’s existing petition to delist the mouse, another petition will be close behind.

If that happens, both sides of the debate will again look to science for support. But in the end, science may represent more of a trap than a solution. Science can answer questions about this mouse’s physical and genetic traits and its role in the ecosystem, but it cannot make the final call. The question of whether the Preble’s mouse —and the vanishing streamside habitat along Colorado’s Front Range — deserve protection is one that society must answer for itself.

Christie Aschwanden is an award-winning freelance writer in Cedaredge, Colorado. Her work has appeared in more than 30 publications, including National Wildlife, New Scientist and Skiing.

Sidebar

A few scientific definitions

Terms commonly used in endangered species discussions – species, subspecies and distinct population segment – are explained