Southern Plains Woodrat
Order Rodentia : Family Muridae : Neotoma micropus Baird

Description. A large, gray-colored rat with large ears and relatively short, heavy, sparsely-haired tail. Differs from Neotoma floridana, to which it is most closely related and which may occur in the same area, in gray, often bluish-gray, dorsal coloration. Upperparts pale drab, mixed with blackish hairs along the back; tail blackish above, grayish below; underparts and feet white. External measurements average: total length, 351 mm; tail, 163 mm; hind foot, 41 mm. Weight, (males) 272-310 g; (females) 204-243 g.

Distribution in Texas. Found in western two-thirds of state eastward to Johnson County in north and Gulf Coast in south.

Habits. This rat is characteristic of the brushlands in the semi-arid region between the timberlands and the arid deserts to the west. Unlike other woodrats, it is rarely associated with rocks or cliffs; rather, it is usually found associated with cactus or some of the thorny desert shrubs. It is at home in thickets of cacti, mesquite, or thorn bush where it constructs a house of sticks, joints of cactus, thorns, and other readily available material. Frequently, an underground burrow system is added, particularly in localities where building materials are not abundant. These houses may be a meter or more high with two or more openings near the base to which well-worn trails lead through and over the spiny vegetation. So well protected are these rats by their spiny fortresses that, when at home, they seldom are molested by larger animals.

Their food consists almost entirely of vegetation; the thick blades of the prickly pear and the juicy fruits of many species of cactus are favored items. Specific items include the thick basal parts of the leaves of sotol, blades of agaves, beans and pods of mesquite, and acorns. Their food also supplies the necessary water.

The breeding season is restricted to early spring and there is some evidence that the species is monestrous and produces only one litter a year. The usual number of young per litter is three, but ranges from two to four. The gestation period is about 33 days. At birth the young weigh about 10 g, but growth is rapid. They are weaned when about 30 days old and at the age of 3 months are nearly full-grown and weigh about 85% as much as adults. At the age of 300 days they are sexually mature.

Under suitable conditions the population density may become high, at which times the rats may compete seriously with livestock and big game animals for forage. However, they ordinarily are not serious pests.

Photo credit: John L. Tveten.