Preble's meadow jumping mouse conquers Wyoming -- again

That gnashing of teeth and muttered cursing you hear is coming from energy companies and developers north of the state border. Last week, U.S. District Judge John L. Kane ruled that an obscure jumping mouse should be considered a threatened species not only in Colorado but in Wyoming, too -- a reversal of a Bush-era decision that many critics considered an attempt to fragment and erode the protections of the Endangered Species Act.

Controversy over the shy, nocturnal Preble's meadow jumping mouse dates back to the 1990s, when the U.S. Fish and Wildlife Service first proposed listing the tiny rodent as an endangered species. That set off waves of panic among development interests, since the mouse is found principally along a band of riparian corridors on the east side of the Rockies from Cheyenne to Colorado Springs -- the same Front Range that's been all but devoured by urban sprawl.

Most people have never seen a Preble's; they weigh less than an ounce and hibernate seven months of the year. For years, scientists couldn't agree if the Preble's is even a valid subspecies of the more common Bear Lodge meadow jumping mouse. But even as that argument was being resolved in favor of the Preble's, a 2008 decision by the US Fish and Wildlife Service stripped the mouse of ESA protection in Wyoming while narrowing its designation of the animal's habitat in Colorado.

Under Ken Salazar, the Department of the Interior has backed off its previous efforts to treat endangered species differently in different states, and Judge Kane denounced the former policy as a "dubious legal opinion." He found that the mouse had enjoyed protection in Wyoming for a decade before the 2008 de-listing, with little disruption of development and governmental plans.

Groups that brought the lawsuit hailed the ruling. "Animals don't recognize state boundaries," noted Josh Pollock, conservation director of the Center for Native Ecosystems, "so the idea of stripping protection for an endangered species based on a political boundary was always a bad one."

More from our Follow That Story archive: "A Split Decision for Mighty Mouse."