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Cave National Park is really two parks in one. The surface is 28,000
acres of a complex mix of prairie grasses and ponderosa pine forest
ecosystems. Seventy-five percent of the Park is open grassland,
and living in that ecosystem is a large variety of mammals.
One
of the more interesting sociable wild animals of the grasslands
is the prairie dog, a rodent that belongs to the squirrel family.
The name "prairie dog" came from their bark-like call,
not from their appearance. They were called "petit chien"
or little dog, by early French explorers and were scientifically
described in the journals of Lewis and Clark.
The
Park has only one species of prairie dog, the black-tailed prairie
dog, named for the black tip of its tail. Black-tailed prairie dogs
have small ears, short tails, and muscular legs. Their fur is buff-colored
and often blends with the earth in which they dig their burrows.
Listen to the prairie dog (29k wav file)
Prairie
dogs rely on keen hearing, excellent eyesight and a communal
warning
system for protection against predators. They are social animals
and the areas they inhabit are known as towns or colonies. Town
is a good term because, in a way, their towns are much like ours.
A dog town may vary in size from an acre to several hundred
acres.
In the 1800's, dog towns were described as stretching for miles;
some extremely large towns are still found in South Dakota.
A typical prairie dog
town consists of groups of prairie dogs that occupy and protect small
areas within the town. These groups of prairie dogs are known as coteries,
which may be compared to "neighborhoods" of human towns. Individual
prairie dogs stay in their own neighborhoods. A typical coterie consists
of one adult male, three or four adults females, and their young up to
one year of age. The residents of each coterie protect their territory
from intruders, including prairie dogs from other coteries within the
town.
Members
of the coterie cooperate with one another. Competition for food
and shelter is uncommon within the coteries, and all members occupy
a nearly equal social position. Members of the coterie recognize
each other with a "kiss." They may also be seen grooming
each other, cooperating in the construction of a burrow, aiding
each other in defense of the territory, eating together, playing
with one another, or standing side by side on a mound of earth.
Communication
between the members of a town is very important and highly specialized.
As many as ten different calls have been described, including sounds
for warning, defense, territoriality, fear, or fighting. A warning
cry from one prairie dog sends all within earshot hustling for their
burrows.
Prairie
dog burrows have not been studied intensively, but some general
features are known. Depth of the burrow system is often governed
by the local soils. In deep soil, the burrows may extend downward
for ten or more feet, averaging 24 feet of tunnel per entrance.
The prairie dogs pack a conical mound of soil around the entrance
of the main burrow to serve as a lookout post and as protection
against flooding. The entrance tunnel section extends steeply downward
for several feet with the next tunnel section being gently inclined,
descending down to the nest. The nest chamber is usually lined with
grasses. Some tunnels then return to the surface, often with a depressed,
crater-like opening marking their terminus. Several burrows may
be connected underground. Tunnel plugs are common, but may be quickly
re-excavated in emergencies.
Prairie
dogs only give birth to one litter per year. The breeding season
is mid-March to mid-April, with the young being born 4 to 5 weeks
later. The size of the litter varies from 2 to 8 young, which are
nursed by the mother for about 6 weeks. During May and the early
part of June, the young begin to emerge from their burrows for the
first time. At this time, yearlings (young from the previous year)
and some adults may relocate, leaving the young pups to feel secure
both socially and environmentally in the old burrow. When prairie
dogs relocate, they take over abandoned holes or dig new holes at
the edge of the town. A few may travel miles in search of new areas,
but once away form the communal warning system, most are easy prey
for predators.
Black-tailed
prairie dogs have incomplete hibernation, their activity and appetite
are decreased during the winter. They may sleep for many days at
a time, but the town is usually active during the milder days of
the winter.
Common predators
of the prairie dog include coyotes, bobcats, eagles, hawks, badgers,
and weasels. One member of the weasel family, the black-footed ferret,
deserves special mention. They are perhaps the rarest mammals in
North America, depending primarily upon prairie dogs for food. Widespread
poisoning of prairie dog towns endangered the existence of this
interesting mammal.
Other
animals may also be found in prairie dog towns. Snakes, including
rattlesnakes, are fond of using abandoned burrows as homes, as are
burrowing owls, birds with long legs and short tails. The owls can
sometimes be seen standing on a mound in the midst of a prairie
dog colony, creating little or no disturbance among the other inhabitants
of the town.
For more information
about Wind Cave National Park's prairie dog management plan click
on management
plan.
More...
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