|The Mammals of Texas -
Rodentia : Family Muridae : Peromyscus
Description. A medium-sized,
long-tailed, white-footed mouse; tail equal to or longer
than head and body, sparsely haired, slightly tufted and
indistinctly bicolor, darker above; ankles dusky, the
feet white; ears moderately long (19-22 mm from notch);
proximal two-fifths of sole of hind foot hairy;
upperparts pale cinnamon or hair brown to sepia; sides
with narrow ochraceous buff lateral line; underparts
white. External measurements average: total length, 197
mm; tail, 103 mm; hind foot, 22 mm. Weight, 22-36 g.
Distinguished from P. difficilis chiefly by
smaller ears and shorter fur; from P. pectoralis by dusky instead of white ankles.
Distribution in Texas. Trans-Pecos region
and along escarpment of Llano Estacado and in adjacent
parts of Panhandle.
Habits. These mice are usually
associated with brush and trees, but they have been
trapped in a number of habitats including stream banks,
rock walls, talus slopes, and cabins. In the Guadalupe
Mountains of western Texas, they are common in the open
pine-fir forest at 2,400 m where they show a decided
preference for areas of down logs and brush piles. Vernon
Bailey remarks that they seldom burrow into the ground
but rather utilize any natural cavity that offers
concealment and protection. The nest is a globular
structure of dry plant fibers, mostly grasses.
They are adept at climbing. Victor
Cahalane observed that several mice, upon escaping from
his live traps, fled into trees in preference to running
on the ground. They climbed easily, but not fast, and
seemed to be at home off the ground. Without doubt they
garner much of their food in trees and utilize hollows in
them for dens. They are almost entirely nocturnal in
habit and are active the year round.
They feed on a variety of plant items.
In the Guadalupe Mountains, they feed extensively on pine
nuts and Douglas fir seeds; in the oak belt, acorns are a
favorite item. They also feed on hackberries, juniper
berries, and cactus fruits.
The breeding season extends through
most of the year. Gravid females have been taken from May
to December, but the presence of half-grown young in May
indicates that breeding begins as early as March or
April. Several litters of two to five (average three)
young may be reared in a year, but the peak of production
is in spring and early summer. The young are blind and
hairless and weigh about 2 g at birth.
Usually these mice are of little or no
economic importance except in instances where they occur
in numbers around and in cabins and granaries in wooded
areas. In such instances they can be removed readily by