About the mouse

* Name: Preble's meadow jumping mouse (Zapus hudsonius preblei).

* Behavior: It feeds voraciously and produces multiple litters before hibernating for six months of

the year.

* Size: Hardly larger than a house mouse and usually weighing between 18 and 22 grams, the mouse will add an additional 20 percent of its weight to prepare for the long winter underground.

* Diet: Arthropods, seeds, vegetation and fungi in grassland vegetation surrounding

willow habitats.

* Appearance: True to its name, it has large hind feet and hind legs that allow it to leap distances of 5 to 6 feet. To counterbalance the mouse while it bounds through dense, herbaceous vegetation, it has a long tail that encompasses nearly two-thirds of its total length.

Source: The Nature Conservancy, Colorado Chapter

WASHINGTON - An acrobatic mouse is threatening Bush administration efforts to give Western developers an upper hand over endangered species.

The Preble's meadow jumping mouse of Colorado and Wyoming is in fact a unique creature with "distinct evolutionary lineages that merit separate management consideration," says a U.S. Geological Survey study presented Wednesday to senior Interior Department officials.

"Those populations facing demographic challenges should be afforded high conservation priority," the study says.

That finding contradicts research touted by Interior Secretary Gale Norton last February when she proposed removing the mouse from the government's endangered species list. Critics say it also undercuts the administration's claim that it uses the best science available in promoting fewer protections for imperiled wildlife.

The previous study, which was done by a biologist since hired by Norton's department, concluded there was no genetic difference between the Preble's meadow jumping mouse and the much more common Bear Lodge meadow jumping mouse.

Listed by the government as a threatened species since 1998, the Preble's meadow mouse stands in the way of any project that could damage its habitat, a broad swath from Colorado Springs north through Denver and Fort Collins and reaching to Laramie.