|The Mammals of Texas -
Banner-tailed Kangaroo Rat
Rodentia : Family Heteromyidae
: Dipodomys spectabilis Merriam
Description. A large, four-toed,
long-tailed kangaroo rat; tail about 1.5 times as long as
head and body, with a distinct white tuft at end; hind
foot broad and usually 50 mm or more in length;
upperparts dark buff; black facial markings and stripes
on tail conspicuous. External measurements average: total
length, 350 mm; tail, 210 mm; hind foot, 53 mm. Weight,
115 g. Dental formula as in Perognathus flavescens.
Distribution in Texas. Occurs in western
and central Trans-Pecos region and north to Lubbock
Habits. This large kangaroo rat
appears to be limited in distribution to sparsely
brush-covered slopes and low hills at elevations usually
between 1,200 and 1,500 m. In Trans-Pecos Texas, it is
most abundant on slopes covered with scattered, mixed
stands of creosote brush and acacias on hard and
moderately gravelly soil. It has never been encountered
in loose soils or drift sands.
The large complex mounds of these rats
are unmistakable evidence of their presence. On soils
that will pack and withstand weathering, the mounds may
be over 1 m in diameter and from 9 to 130 cm in height,
but on sandy soils they are less pretentious. As many as
a dozen openings admit the rat to the complex system of
galleries and side branches, and from them lead
conspicuous trails across the surrounding sparse
vegetation to the feeding areas. In addition, subsidiary
burrows or "duck-ins" are relied upon for
protection. Usually only one rat occupies each den.
These rats are exceedingly fleet and
agile, and to catch them at night by running them down is
no mean feat. Once in the hand they can inflict painful
wounds with their teeth unless handled carefully.
Their food is almost entirely plant
materials with seeds ranking high on the list. Green
vegetation is eaten on occasion. Large quantities of food
are stored in the dens to carry them over the periods of
scarcity. Stores from a fraction of a gram to well over 5
kg have been found. Charles Vorhies and Walter Taylor
listed 13 species of grass and 29 other plants that
contribute to their diet. Needle grass, grama grass,
mesquite, and a composite weed (Aplopappus) were
the most important foods. They seldom drink, even if
water is present.
The breeding season begins in January
and continues into August. The young begin to appear in
March, sometimes as early as February, and nearly
full-grown juveniles are common by April. The gestation
period is not known. The young are naked at birth, and
the eyes and ears are closed; the number per litter
varies from one to three but usually is two. They are
born in an underground nest composed of fine vegetation
and chaff refuse from the food. Nest chambers vary in
size from 15 by 20 cm to 20 by 25 cm.
Their known natural enemies include
fox, bobcat, and coyote. Other animals
also probably prey upon them.
Banner-tails are sometimes of economic
importance locally. In periods of drought they may do
serious damage to rangelands by gathering and eating
grass seeds. In such places, controlling their
populations may be necessary.
Photo credit: John L. Tveten.