The pinyon mouse is a widespread but rarely photographed rodent of Colorado’s rocky woodlands. Open occurrence databases hold 1303 records for it here, nearly all from survey and museum collections rather than field photos, as befits a small, strictly nocturnal deermouse.
Pinyon, juniper, and broken rock
True to its name, this mouse is bound to pinyon-juniper woodland and the rocky mesas and outcrops that run through it. In Colorado that country lies mostly in the west and south, and the records follow it, led by Moffat and Montezuma counties and the canyon-and-juniper breaks of Las Animas and Huerfano. It wants both the tree cover for food and the rock crevices for shelter, and where the two meet it can be one of the more numerous small mammals.
An outsized-eared climber
The pinyon mouse gives itself away by its remarkably large ears, nearly as long as its hind foot, and it is an agile climber that dens in rock cracks and juniper hollows. Juniper berries and pinyon seeds are dietary staples, rounded out with other seeds and insects. It is active year-round after dark, so the summer rise in its record simply tracks the field season rather than any real change in the animal.
Status in Colorado
NatureServe ranks the pinyon mouse S4, apparently secure, in Colorado. Its fortunes are tied to the health of the state’s pinyon-juniper woodlands, the habitat that gives the mouse its name.
Full species profile
