Cynomys parvidens 267mate within several days of their emergence from hiberna-
tion; multiple paternity is common (more than 70%). Fe-
males attain sexual maturity and mate as yearlings. Males
sometimes mate as yearlings, but they commonly delay
their fi rst mating until they are 2 years old. The young are
born after a gestation of 28–30 days, and they remain under-
ground for about 5.5 weeks. Litter size when juveniles fi rst
appear aboveground from the nursery burrow is most com-
monly four or fi ve (range = 1–7). Females produce one litter
per year, and although most females mate, only about 67
percent successfully wean a litter. The young appear above-
ground when they are 6 weeks old and are weaned soon af-
ter ward. Sur vivorship in t he fi rst year after emergence from
the nursery burrow is usually only about 50 percent for both
sexes, and fewer than 30 percent remain alive at 2 years of
age. Males sometimes live as long as 7 years, and females
occasionally can be as much as 8 years old. Utah prairie dogs
are social, and they live in colonies (often called towns).
Their burrows can be recognized by the ring of excavated
soil around the entrance. Burrows can be complex, with up
to 10 entrances and 1–3 nests. Burrows typically do not ex-
ceed 6 m in length and perhaps 3 m in depth. Colonies vary
considerably in their size and density. C. parvidens is highly
social, and the typical social units (known as clans) are com-
posed of an adult male, several adult females, and immature
young less than 2 years of age. Amicable interactions among
adults and juveniles include kissing, sniffi ng anal and oral
glands, and playing; hostile interactions among adults of all
species include fi ghts, chases, and territorial disputes. Adult
females within a social group are always close kin. Follow-
ing the fi rst emergence of juveniles from their nursery bur-
rows, females commonly will nurse the off spring of other
females until weaning is complete (in another one to three
weeks); benefi ciaries of such communal nursing are usually
close kin, such as grandoff spring, nieces, and nephews.
C. parvidens can often be seen eating grasses, forbs, fl ow-
ers, seeds, and the fruits and seed of shrubs. Alfalfa (Medi-
cago sativa) planted for hay is a favorite food. In addition,
these prairie dogs are known to consume insects and feed
on cattle feces. Individuals sit on their haunches or stand
upright on two feet to scan for predators. Vigilance func-
tions mostly to improve the probability of detecting a preda-
tor, but it is also used to monitor the activities of nearby
conspecifi cs. Infanticide by adult males is known to occur
in C. parvidens. Alarm calls are given in response to the
large-bodied mustelids, felids, canids, and raptors that func-
tion as this species’ principal predators. Historically, Utah
prairie dogs were hunted occasionally for food and fre-
quently for target practice or sport. They were often (and
sometimes still are) falsely viewed as a signifi cant competi-
tor for forage or as a threat to livestock, due to open burrows
that can be stepped into by grazing animals. However, some
researchers consider Cynomys to be a keystone species for
ecosystem health. As a potential pest, Utah prairie dogs
were often poisoned in the 1900s in an attempt to extirpate
them within their small isolated range, resulting in massive
declines from populations estimated to have been perhaps
95,000 individuals over 1800 km^2. C. parvidens is a lso suscep-
tible to outbreaks of sylvatic (bubonic) plague that rapidly
eliminate local populations.general references: Haynie et al. 2003; Hoogland 2001,
2003b, 2006, 2009; Manno 2007; Pizzimenti and Collier 1978;
U.S. Fish and Wildlife Service 1991.Cynomys parvidens. Photo courtesy Elaine Miller Bond.