SANTA FE, N.M. — Zapus hudsonius luteus, the scientific name for the New Mexico meadow jumping mouse, is a small mammal historically found in riparian wetlands along streams from southern Colorado to central New Mexico.
Its habitat requires dense vegetation that includes non-woody grasses at least 24 inches tall.
“This suitable habitat is found only when wetland vegetation achieves full growth potential associated with perennial flowing waters,” according to documents published in the federal register by the U.S. Fish and Wildlife Service.
“This vegetation is an important resource need for the New Mexico meadow jumping mouse because it provides vital food sources (insects and seeds), as well as the structural material for building day nests that are used for shelter from predators.”
The mouse, with a lifespan of three years or less, has a limited capacity for population growth, according to the document.
It hibernates up to nine months of the year, leaving a short time for it to produce a litter of seven or fewer offspring, raise them and store up fat reserves to make it through hibernation.
Through surveys taken since 2005, Fish and Wildlife identified 29 populations of the mouse – two in Colorado, 12 in Arizona and 15 in New Mexico – but it notes that 11 of the 29 populations have been “substantially compromised” since 2011 due to water shortages, excessive grazing, wildfires and post-fire flooding.
The populations range in size from seven to 48, though Fish and Wildlife acknowledges some of the data is imperfect. It says it based its judgments using “the best available scientific and commercial data,” and peer review of its conclusions.
Its action plan calls for additional surveys to be conducted in areas where mouse populations are known to exist or where they could be expected to exist.
Those areas include the Sangre de Cristo Mountains in northern New Mexico and San Juan Mountains in southern Colorado, the Rio Grande Valley, the Santa Fe and Lincoln national forests and the Apache-Sitgreves National Forest in eastern Arizona.
“None of the 29 populations known to exist since 2005 are of sufficient size to be resilient,” the document states. “Therefore, we conclude that the overall probability of persistence is low in the near term and decreasing in the future due to the lack of adequate resiliency, redundancy, and representation.”