||The Mammals of Texas -
Rodentia : Family Muridae : Neotoma
Description. A medium-sized woodrat with
large ears, bulging black eyes and relatively short,
distinctly bicolor tail (grayish brown above, white
below), densely covered with short hairs; throat, and
usually breast and chin, with hairs white to base;
upperparts dull pinkish buff, brightest along sides,
thinly suffused with blackish; underparts and feet white.
External measurements average: total length, 328 mm;
tail, 152 mm; hind foot, 34 mm. Weight, 136-294 g.
Distribution in Texas. Found in Panhandle
and broken country south of Red River to Bexar and Uvalde
counties, and westward throughout much of the
southwestern part of state.
Habits. This woodrat is
characteristic of the brush lands of the southwestern
deserts. The availability of such desert shrub vegetation
as prickly pear, cholla cactus, mesquite, sotol,
lechuguilla, and creosote bush which afford shelter for
their houses, seems to affect their abundance more than
the nature of the terrain. Cholla cactus and prickly pear
offer preferred home sites because they supply not only
protection but also food and water. Occasionally, their
houses are built in the open or in sparse vegetation. In
rocky situations the associated cracks and crevices
afford the usual den site.
The house is a crude cone of sticks,
cactus joints, and other rubbish which surrounds the nest
proper a compact, cup-shaped structure composed of
shredded dry leaves, blades of grass, and weed stems.
Access to the house is by means of openings near the base
to which well-worn trails lead. Frequently, especially in
localities where building materials are scarce, the house
is supplemented by a system of underground burrows.
Although several houses may occupy a
small, desirable patch of cacti, the rats are not social
creatures. Only one animal or a female and her young
occupy each house. Their home range or feeding
territories overlap considerably, but to each rat his
house is a personal affair and thus is not shared.
The menu of these rats consists of a
variety of desert plants, but the cactus family led the
list of more than 30 items found in the stomachs of 360
rats examined. Mesquite and forbs were next in
preference. Grasses constituted less than 5% of their
fare, but small quantities were regularly consumed. The
amount of animal material consumed (ants, birds, beetles,
and grasshoppers) was less than 1% of the total diet. The
habit of storing food is not well developed in these
rats, but small quantities of food are usually found at
each house. Drinking water is not required because of the
high water content in their choice of foods.
The breeding season is restricted
largely to the period from January to September. At least
two and possibly three or more litters of two or three
young each may be reared during this period. The period
of gestation is approximately 38 days. At birth the young
are helpless, weigh about 11 g, and are about twice the
size of newborn house rats. As is the case with other
woodrats and many related species of mice, the young ones
have specially developed front teeth that permit them to
grasp the nipples of the mother and to be dragged along
behind her, skidding and bouncing along on their backs,
when she leaves the nest. They grow rapidly; the ears
open on the 13th to 15th day, the eyes open on the 15th
to 19th day, and they are weaned when 62-72 days old.
When about 6 months old they are almost indistinguishable
from their elders.
The spiny fortress in which the house
is located, coupled with the nocturnal habits of the
rats, makes them relatively safe from most predators.
Owls catch a few individuals, as do coyotes, bobcats,
ringtails, and weasels but their chief natural enemies
appear to be the large desert gopher snake and the
rattlesnake, both of which can enter the houses of the
rats with impunity.
Photo credit: R.D. Porter.