|The Mammals of Texas -
Mexican Ground Squirrel
Rodentia : Family Sciuridae : Spermophilus
Description. A rather small ground
squirrel with usually nine rows of squarish white spots
on back; tail about two-fifths of total length,
moderately bushy; ears short and rounded; upperparts wood
brown or buffy brown with rows of conspicuous white
spots; sides and underparts whitish or pinkish buff.
External measurements average: total length, 301 mm;
tail, 118 mm; hind foot, 41 mm. Weight, (males) 227-330
g; (females), 137-198 g.
Distribution in Texas. Occurs throughout
much of southern and western Texas (west to Culberson,
Jeff Davis, and Presidio counties in the Trans-Pecos),
north almost to the Red River just east of the Panhandle.
Habits. Mexican ground squirrels
inhabit brushy or grassy areas. In southern Texas, they
are frequently associated with mesquite and cactus flats.
In Kerr County, they are most common in pastures and
along the highways; in Trans-Pecos Texas, they are
frequently found in areas dominated by creosote-bush (Larrea).
They live in burrows, the openings to
which are usually unmarked by a mound of earth. Sandy or
gravelly soils are preferred, but the squirrels are by no
means restricted to them. One squirrel may utilize
several burrows, one of which is the homesite; the others
are temporary refuges. The burrows are typically from 6
to 8 cm in diameter, enter the ground at a 30 to 50
degree angle, and range from 30 to 125 cm below the
surface. The brood chamber is usually at the deepest part
in a side tunnel. There are often two openings to the
burrow system, possibly to facilitate escape. They also
utilize burrows of pocket gophers. Although somewhat
colonial, they are rather unsocial and drive away other
squirrels that intrude upon their privacy. Their home
range is about 45 m in radius.
Near Midland, most of the squirrels are
in hibernation by November 20, although there is some
activity throughout the winter. Likewise, in the
Trans-Pecos they are seldom seen in winter, but in South
Texas they remain active throughout the year.
Their food in early spring is chiefly
green vegetation. They are known to feed on mesquite
leaves and beans, agarita leaves and berries, Shasta
lily, Johnson grass, pin clover, and cultivated grains.
Insects also contribute importantly to their diet. In
early summer about half of their diet is insects. They
are fond of meat and frequently can be seen feeding upon
small animals killed on the highways. In captivity they
exhibit a cannibalistic tendency and kill and eat their
cage mates, particularly if a strange squirrel is placed
with them. Occasionally they climb into low bushes to
forage, but most of their food is gathered on the ground.
Breeding begins in late March or early
April and lasts for a week or two. The gestation period
is probably not more than 30 days. The young, about five
per litter, are born blind and almost naked and weigh
from 3 to 5 g.
Photo credit: John L. Tveten.