|The Mammals of Texas -
Eastern Harvest Mouse
Rodentia : Family Muridae : Reithrodontomys
humulis (Audubon and Bachman)
Description. A diminutive harvest mouse
montanus, but upperparts
deep brown or gray, heavily mixed with black, especially
on the mid-dorsal area; ears blackish all over rather
than dark at the base and light at the tip; tail about as
long as head and body, the dark dorsal and light ventral
stripes about equal in width. External measurements
average: total length, 126 mm; tail, 61 mm; hind foot, 16
mm. Weight, 10-15 g.
Distribution in Texas. Known in the
eastern part of the state, west to Fort Bend, McLennan,
and Hunt counties.
Habits. The eastern harvest
mouse is found mainly in habitats dominated by grasses
and other herbaceous plants characteristic of early
vegetational succession, including places such as
abandoned fields, weed-filled ditches, and briar
Eastern harvest mice are essentially
nocturnal, although at times they may be active during
the daylight hours, particularly during cold weather.
During periods of cold weather, these mice huddle
together in the nest at night to reduce heat loss from
their bodies, and they feed in the daytime when it is
R. humulis constructs nests of
shredded grass and plant fibers that are placed on the
ground in tangled herbage or above the ground in a clump
of grass. The nest, which is about the size of a
baseball, generally has a single entrance.
Although breeding may occur throughout
the year, most births take place between late spring and
late fall. Litter sizes range from one to eight (average,
three to four), and the gestation period is 21-22 days.
At birth the young weigh approximately 1.2 g. The eyes do
not open until 7-10 days, and weaning takes place between
the second and fourth weeks. The young become sexually
mature and are capable of breeding at about 11-12 weeks
The food habits of R. humulis
are not well known. They appear to feed almost wholly on
seeds and grain, but are known to eat grasshoppers and
crickets while in captivity.
Photo credit: John L. Tveten.