Download Keystone Species of the Wyoming Prairie

Keystone Species of the Wyoming Prairie
Andrea Watson
September 30, 2001
Jeanine Canty
Educating for the Future: Multicultural and Environmental Issues
Scientists and researchers define a keystone species as an animal that is essential to its
environment. A keystone species plays a major role to the food web, the habitat, and the
general surroundings of the environment of which the species lives. On the prairie of
Wyoming, the keystone species is the prairie dog, specifically the black-tailed prairie
dog. The National Wildlife Federation, the Rocky Mountain Animal Defense, as well as
the state’s Natural Resources Department all conclude that the black-tailed prairie dog
plays a crucial roll in the prairie environment and that it is definitely the keystone species
of this ecosystem. The prairie dog is important to the Great Plains, including Wyoming,
not only because of its presence but also because of its colonies, burrow structure and
grazing habits. Its survival is pivotal to its environment as well as to a collection of other
wildlife, as well.
Prairie dogs live on the open prairie and short grasslands of the Great Plains. They are
mammals that live in family groups called colonies. They communicate through a variety
of barking sounds, which is what possessed explorers to name them dogs (Kenny, 2001).
There is a growing concern that the number of black-tailed prairie dogs is rapidly
declining. There are a variety of groups such as the Rocky Mountain Animal Defense
and National Wildlife Federation that have urged that this keystone species be left alone
before it becomes endangered. In fact the US Fish and Wildlife Service found that the
black-tailed prairie dog was “warranted but precluded to be listed as a threatened species
under the Endangered Species Act (Rocky Mountain Animal Defense, 2001). Prairie
dogs are often bulldozed, poisoned, and used for target practice because they are thought
to be a nuisance to landowners, ranchers, and hunters as their homes are thought to be
dangerous to livestock.
Prairie dogs create huge, complex tunnels and mounds, in the midst of short grasses,
called prairie dog towns or colonies. These towns provide shelter and homes for many
other animals and birds such as deer mice, kangaroo rats, grasshoppers, beetles, and the
meadowlarks. Their burrowing activity loosens and mixes the soil so that is more able to
support plant life and prairie vegetation. According to the Rocky Mountain Animal
Defense “their foraging and feeding practices enable a more nutritious, diverse and
nitrogen-rich mixture of grasses and broad-leafed vegetation to grow” (Rocky Mountain
Animal Defense, 2001). In turn these grasses help to feed the thousands of cattle and
bison that live on the Wyoming prairie.
The black-tailed prairie dog that lives on the Wyoming prairie is a critical food source
for a large variety of animals. Coyotes, snakes, fox, ferrets, ferruginous hawks, badgers,
weasels, and eagles are animals that depend on prairie dogs for their food source. The
high rate of prairie dog reproduction enables the species to survive while also providing
food for the many other prairie animals. According to the National Wildlife Federation
the black-tailed prairie dog is the only prairie dog as well as one of few rodents that do
not hibernate in the winter. This allows for one of only a few food sources for many of
the prairie dog’s predators during the long, cold, winter months (National Wildlife
Federation, 2001). Not only are prairie dogs essential to predators for food but for other
reasons as well. Several prairie species depend on the prairie dog’s burrows as homes.
The Rocky Mountain Animal Defense predicts that its research indicates that there are
over two hundred wildlife species that have been recorded living on or near prairie dog
colonies (Rocky Mountain Animal Defense, 2001). Animals such as rabbits, snakes, and
small rodents live in abandoned as well as inhabited prairie dog burrows. In fact the
burrowing owl will only make its nest in a prairie dog burrow. Larger animals including
coyotes, foxes, and badgers enlarge abandoned burrows for their own homes (Kenny,
2001).
Prairie dogs also help in land problems such as overgrazing. For example, they
control noxious weeds and native invaders, which reproduce on overgrazed grasslands.
Prairie dogs help remove pods, seeds, and strip bark from young seedlings, which in turn
contributes to seedling extinction of unwanted weeds (Rosmarino, 2001). While grazing
animals cause the soil to become compacted, the prairie dog’s burrowing activity keep
the soil loose so that it can absorb water and other nutrients. They also create patches of
exposed soil when building their mounds and burrows, which become sites for annual
grasses and wildflowers to become established (Kenny, 2001). Research has shown that
prairie dogs like to stand on their mounds and look across the prairies. So that they are
able to see long distances they often clip tall grasses and other vegetation. This clipping
helps improve the nutrient value of native grasses, enabling it to grow thicker and faster
(Kenny 2001).
Prairie dogs are also considered to be a keystone species to the prairies of Wyoming
because they are what scientists call water conservationists. While humans destroy water
areas of the plains by damming up rivers and streams for crop and livestock agriculture,
prairie dogs actually conserve the water that falls in the form of rain (Rosmarino, 2001).
They are responsible for channeling this rainfall into their colonies, which produces an
underground storage system. While seemingly small, a large amount of prairie dogs
across the Plains can conserve a large amount of rainfall per year in a rather arid
environment.
While there are still plenty of black-tailed prairie dogs across the plains of Wyoming,
their numbers are decreasing. The population of the animal depends largely on the
activities of humans. According to the Rocky Mountain Animal Defense there has been
such a drastic population reduction in this animal that they are down to only one percent
of their historical numbers. They also warn, “methods of prairie dog extermination are
shocking. Black-tailed prairie dogs are bulldozed alive, subjected to a slow, prolonged
death by poisoning, and shot for sport and fun” (Rocky Mountain Animal Defense,
2001).
Not only are prairie dog numbers decreasing by human hands but also by disease.
Many prairie dogs are infected with a plague, or bacterial infection, which is transmitted
by fleas. The infection kills the prairie dog but is also a threat to domestic animals that
are unleashed and taken to prairie dog sites. Once a domestic animal such as a dog or cat
is infected the disease can be passed on to humans. If this happens large populations of
prairie dogs can be exterminated to decrease the threat of the plague to communities of
people (Kenny, 2001).
For many reasons the black-tailed prairie dog is a vital part of the prairie ecosystem.
Their existence is very important to other species, the grasslands, vegetation, and soil
conservation of the plains areas, including that of Wyoming. While the prairie dog is
often thought of as a pesky, meaningless rodent, many agencies are finding that they are
much more. Their role as the keystone species of the prairie is very significant. As
stated by the Rocky Mountain Animal Defense: “The black-tailed prairie dog’s very
presence contributes to a diversity of life and whose extinction would consequently lead
to the extinction of other forms of life” (Kenny, 2001). Their declining population
numbers should be taken seriously so that there is no threat of their extinction or
endangerment.
Work Cited
Kenny, Sue. Prairie dogs maintain prairie ecosystem. From the Natural Resources Dept.
Available: http://www.ci.fort-collins.co.us. [2001, August 21].
National Wildlife Federation. Black-tailed prairie dogs are a keystone species.
Available: www.nwf.org/prairiedogs/keystone_species.html. [2001, August 29]
Rocky Mountain Animal Defense. Save the prairie dogs. Available:
www.prariedogs.org/keystonehtml. [2001, August 19].
Rosmarino, Nicole. From the Southern Plains Land Trust. Prairie dogs are a keystone
species of the Great Plains. Available: www.gprc.org. [2001, August 19]