OCTOBER 1989 - City of Boulder

BLACK-TAILED PRAIRIE DOG
Cynomys ludovicianus
Distribution.--An early traveler through Texas reported seeing 400
million prairie dogs in a town that covered 25 thousand acres. Though
their nuubers have decreased, prairie dogs still inhabit much of the
western Great Plains, They range from the Rockies eastward to the
Dakotas, central Kansas and Nebraska, and parts of Texas and Oklahoma.
They are found across the plains of eastern Colorado, in places extending
into lower, open areas of the foothills, such as the male behind
Red Rocks, above Settlers1 Park,
Description.--Prairie dogs are medium-sized ground squirrel with short
tails, short legs, and small ears. They have a larger body and stlorter
tail than the rod squirrel. Ihe body is tan or yellowish above,
whitish below. Man (and extreme) size of 10 males and of eight females, from
Larimer County are: total length, 378.7 (358-400), 371.4 (340-400); length
of tail, 82.2 (71-95), 75.0 (60-84) ; hindfoot, 60.5 (57-63), 61.0 (55-63);
ear, 14.2 (12-17), 14.5 (11-18); greatest length of skull, 64.02 (62.0-67.8),
63.09 (60.5-66 -0) ; zygomatic breadth, 45.20 (43 -6-48 -5) , 44.71 (42.6-48 .O) ;
weights range from 500 to 1000 gr.
Natural History.--Sitting erect atop earthen mounds, barking shrilly,
these rodents are.8 common sight in mixed-grass prairie country. Mounds
mark the entrances to complex burrow systems. They are constructed such
that a convection current circulates air through the burrows. They also
provide a vantage point from which to watch for predators such as coyotes,
foxes, badgers and hawks. Different two-syllable calls convey different
messages.
Social organization has been studied extensively. Towns are divided
into smaller "wards" by geographic features and these are composed of
several "coteriess' or territories. A "coterie" usually consists of one or
two adult males and two to eight females and young. . .
Prairie dogs feed on the %st of the seasonem In spring and
summer they eat seeds, leaves, and stolons of grasses and f orbs, In
fall and winter, dried forbs, roots and occasional insects make up
the diet, Grazing changes the plant community from perennials to
the more productive annuals favored by prairie dogs. Once this
grazing was by bison; now it is by cattle. Prairie dogs are more
symptom than cause of overgrazing.
Active during the day, this species may reduce its activities during
cold weather, but does not actually.hibernate in our area. In March or
April they give birth to two to eight young. In the seventh or eighth
week they are weaned and come above ground. By their first winter, young
dl1 be almost full grown, and reproduce as yearlings. Average longevity
is three years.
Selected References .--King (1955) ; Koford (1958) ; Lechleitner (1969)
Smith (1967).