When the Interior Department recently withdrew a legal memorandum concerning the Endangered Species Act, the Preble's meadow jumping mouse may well have pricked up its ears.
The mouse is the only species that is currently in line to be directly affected by the department's change of stance.
The mouse, known for its long tail and a dark stripe along its back, was originally listed as threatened in 1998 in both Colorado and Wyoming, but after the 2007 memorandum was issued, it lost its protected status in the latter.
Now that the memorandum has been withdrawn, the mouse could regain its threatened status in Wyoming.
The memorandum addressed the phrase in the ESA that says an endangered species is "any species that is in danger of extinction throughout all or a significant portion of its range."
FWS asked the Office of the Solicitor at Interior to look at the issue in the aftermath of a 9th U.S. Circuit Court of Appeals opinion in 2001 concerning the flat-tailed horned lizard.
In the 2007 memo, Interior's then-solicitor, David Bernhardt, concluded that ESA protections could be applied to just a portion of a species' range.
That interpretation was then applied to the high-profile case of the northern Rocky Mountain gray wolf, in which the Fish and Wildlife Service proposed they be delisted in all states within their range except Wyoming.
In 2010, a federal judge in Montana rejected the memorandum's interpretation of the law. Another judge, this time in Arizona, ruled likewise in a case involving the listing of the Gunnison's prairie dog.
Subsequently, Congress intervened in the wolf case by delisting it entirely (E&E Daily, April 11).
That means that the jumping mouse is the only case to which the memo was applied in which litigation is ongoing.
The government has already filed court papers in the District of Colorado, where the case is being heard, asking for the judge to remand the case back to FWS in light of the memo being withdrawn.
FWS now "intends to publish shortly, for notice and comment, a proposed joint policy regarding the interpretation and implementation of the phrase 'significant portion of its range,'" according to a fact sheet that the service sent out following the wolf delisting.
A spokesman had no further comment.
Bernhardt, now a partner at Brownstein, Hyatt, Farber, Schreck, said the issue is one "Interior has struggled with" over the years.
"It would be my hope that they develop guidance sooner rather than later to ensure that career attorneys have guidance on the way this is supposed to be handled," he said.
Jason Rylander, an attorney at Defenders of Wildlife, said that, from his perspective, the ESA always requires listing throughout the range.
The withdrawal of the memo "has potentially wide-ranging significance" in future listings disputes, he added.
Click here to read government motion for voluntary remand in Preble's mouse case.