|The Mammals of Texas -
Plains Harvest Mouse
Rodentia : Family Muridae : Reithrodontomys
Description. A small harvest mouse about
the size of R.
humulis and considerably
smaller than R.
megalotis and R. fulvescens; tail usually less than half of total length
and distinctly bicolor, dark above and light below;
upperparts mixed brown and pale yellowish gray; outside
of ears and flanks pale yellowish brown; underparts dull
whitish. External measurements average: total length, 116
mm; tail, 54 mm; hind foot, 15 mm. Weight, 6-10 g.
Distribution in Texas. Found in western
and central parts of state, east and southeast to Madison
and Bexar counties, respectively.
Habits. These mice appear to
prefer climax, or nearly climax, well-drained grassland.
In Brazos County they occur most commonly in blackland
prairies where the dominant vegetation is bluestem grass
(Andropogon). Their nests are composed of fine
grass compacted into small balls and are either in bunch
grass or just beneath the ground in their burrows.
Their food consists of green parts and
seeds of a variety of plants, including small grains. In
captivity they readily accept rolled oats and sunflower
Available data indicate a year-long
breeding period, at least in Texas. A female captured
January 13 near Bryan gave birth to four young in the
trap; a gravid female was trapped in October. A captive
gave birth to litters in September, October, March, and
April. The gestation period is approximately 21 days; the
number of young per litter ranges from two to five,
averaging three. At birth the young are blind, naked, and
weigh about 1 g. They are well-haired in 6 days, their
eyes open in 8 days, and they are weaned in about 14
days. They are as large as adults in 5 weeks and sexually
mature in about 2 months.
Photo credit: John L. Tveten.