||The Mammals of Texas -
Rodentia : Family Muridae : Peromyscus
Description. A small-eared, long-tailed,
white-footed mouse with tarsal joint of hind foot white;
pelage moderately long and lax; tail longer than head and
body, scantily haired, not sharply bicolor, but darker
above than below, and annulations 20-24 per cm;
upperparts grayish to wood brown; underparts and feet
white; young, bluish gray. External measurements average:
total length, 187 mm; tail, 95 mm; hind foot, 22 mm; ear,
16 mm. Weight, 24-39 g. Most easily confused with P. eremicus, P.
attwateri, and P. boylii. Distinguished from P. eremicus by
having proximal part of sole of hind foot hairy rather
than naked; mammae in three pairs rather than in two.
Differs from P. boylii and P. attwateri in
smaller scales on the tail, and in white, rather than
dusky, tarsal joints and in shorter maxillary tooth row
(often less than 4 mm).
Distribution in Texas. Recorded from most
of Trans-Pecos region and northeastward through central
part of state to Oklahoma (eastern limits of range along
Balcones Escarpment from Bexar County northward to
Habits. This is another
rock-dwelling species, and it often is taken in the same
habitat occupied by P. boylii. In the Chisos
Mountains and again in the Delaware Mountains in
Trans-Pecos Texas, they have been caught in the
oak-juniper belt in traps set among jumbled boulders,
near rock walls, in talus slopes, along rocky
outcroppings, and in buildings. Near Austin, white-ankled
mice are common in the rocky outcropping where the
Colorado River cuts through the Balcones Escarpment; in
Kerr County they prefer rocky bluffs along the rivers and
creeks. In the Davis Mountains region of Trans-Pecos
Texas, they usually are found in the grama-bluestem
association. Elsewhere, in our experience, they are
associated with rocks in oak-juniper woodlands.
They feed on a variety of seeds,
including juniper berries, acorns, and hackberries.
Although their diet has not been studied in detail, other
seeds, some fruits, and insects probably are taken when
available. They readily come to traps baited with rolled
Their breeding habits are not
well-known, but the breeding season extends at least from
March to October. Pregnant females have been captured in
March, April, May, July, August, September, and October,
which suggests that several litters may be reared each
year. The average litter size is three, ranging from two
to five. The gestation period has not been determined,
but it is probably about 23 days as in closely related
species. Growth and development of the young is not well
These mice are abundant in certain
localities and may become troublesome in cabins and ranch
buildings. They usually can be controlled easily by the
use of traps or poisoned grains.
Photo credit: John L. Tveten.