CYNDI SOUZA / Special to the PVT This round-tailed ground squirrel is the only one found so far west since 1891. CYNDI SOUZA / Special to the PVT Richard Manning studies what appears to be a young cactus mouse that was turned up during the survey. Advertisement

AMARGOSA VALLEY -- Biologists have completed their annual mammal surveys in Ash Meadows National Wildlife Refuge and have turned up quite a surprise.

On this trip, a round-tailed ground squirrel, caught in a live trap, was of particular interest because it was the Bio-West crew's first specimen from the refuge, and there are only four known specimens from Ash Meadows.

Though common elsewhere in the state, it was last collected here in 1891 by the Death Valley Expedition. Those four specimens are housed at the Smithsonian's National Museum of Natural History in Washington, D.C.

The team in this more recent case, from the environmental consulting firm Bio-West Inc., conducted small mammal surveys during the spring, summer and fall seasons of 2008 and 2009.

The purpose of the study is to gather baseline information on the presence, distribution, and natural history of small mammals that occur on the refuge.

This information assists refuge staff with their efforts to return Ash Meadows National Wildlife Refuge to a healthy, functioning wetland ecosystem through hydrological and wildlife habitat restoration.

Ash Meadows is home to at least 26 species of plants and animals found nowhere else in the world, some of which are threatened or endangered.

The area is of particular interest to biologists because of the unique presence of water in a desert environment. More than 30 seeps and springs release fossil water (melt from the last ice age) emerging from deep within the earth.

The team was hopeful, but unsuccessful, in seeking the Ash Meadows montane vole. According to Bio-West ecologist Benjamin Chen, "This species is known by only 30 specimens housed in two museum collections. The last known specimens were obtained at Ash Meadows in 1933. It is believed this species is associated with grassy areas adjacent to water. When this habitat was drained for peat mining, the species survival was compromised."

The most common mammals found on the refuge were the cactus mouse and Merriam's kangaroo rat.

Prior to setting the traps in various habitat locations, the team conducted field visits to select and mark sites using GPS.

Use of that GPS technology maintains consistency in data and provides valuable information for future studies regarding trends. This information is captured and collected in addition to species, age and sex of the animal.

Sharman live-traps, box-style arrangements, are baited with rolled oats, then set in late afternoon. Traps are checked early the next morning. Animals generally are released immediately after data are collected and recorded.

Before the close of 2009, the team will return to Ash Meadows to conduct its annual amphibian and reptile survey.

When asked why any of this matters, Chen said, "It's a function of us learning how to participate responsibly with our surrounding environment. The mission of the National Wildlife Refuge System speaks to the fact that the conservation of the environment relates to the preservation of our heritage and the belief that simply because it exists, life -- a species -- is worth protecting, and there is an inherent value in each of the species that make up the complex system that is Ash Meadows."