Nature & Wildlife
Pg 10 - The Sunshine Express
Park Service property.
Contrary to public perception, prairie dogs don¡¯t
reproduce prolifically. Females have only one
litter of 3-5 pups each year and the natural
mortality rate of the young is about 50 percent.
Consequently, the colonies generally do not
spread rapidly over wide areas. Tripp explained
that few connections between colonies across a
landscape exist; so when a colony is wiped out
it may have little chance of being re-colonized.
¡°By preventing plague we can have healthy,
stable prairie dog colonies that we can manage
on public lands,¡± Tripp said.
The conservation work is aimed at preserving
the ecological niche of prairie dogs and prevent-
ing a listing of the Gunnison¡¯s prairie dog under
the federal Endangered Species Act. If the
animal is listed it could lead to various land-use
J. Wenum, area wildlife manager in Gunnison,
explained that when landscapes are restored to
a more natural condition, more uses can be ac-
¡°If you have healthy, functioning landscapes
you don¡¯t have to be focused on limiting uses,¡±
Wenum said. ¡°A healthy landscape will accom-
modate agriculture, recreation and wildlife.¡±
The testing of the oral vaccine will continue for
a few more years, and biologists are cautiously
optimistic that the vaccine will prove to be ef-
fective at limiting plague.
¡°We won¡¯t be able to prevent plague in every
colony. But this work will help to stabilize the
overall population at its current distribution and
benefit this important species,¡± Tripp said.
For more information about prairie dogs and
other wildlife species see: cpw.state.co.us
Preventing Threats to Stability
Researchers Finding Success
Fighting Plague In Prairie Dog Colonies
Gunnison, CO: Work to protect the Gunnison¡¯s
prairie dog by Colorado Parks and Wildlife has
proven successful during the last four years and
biologists are continuing with more research to
improve methods to sustain populations.
¡°In some situations prairie dogs can be seen
as pests, but they are critical in the environ-
ment and help to promote survival of numerous
other species such as burrowing owls, badgers
and raptors,¡± said Dan Tripp, a wildlife disease
researcher with Colorado Parks and Wildlife.
In Colorado there are three species of prairie
dogs. The Gunnison¡¯s prairie dog resides primar-
ily in the southwest portion of the state. The
others are the white-tailed prairie dog which lives
mainly in northwestern Colorado, and the black-
tailed prairie dog which inhabits areas along the
Front Range and eastern plains.
Plague, caused by a non-native bacteria carried
by fleas, has been identified as a threat to the
stability of Gunnison¡¯s prairie dog populations
in Colorado. Outbreaks of plague frequently kill
every prairie dog in a colony. To combat the
disease, agency biologists are dusting prairie
dog burrows with an insecticide powder that kills
fleas. Researchers are also evaluating the ef-
ficacy of oral vaccine baits which may prevent
plague in the animals.
The bacteria that causes plague was transported
to North America around 1900 and was subse-
quently found in Colorado around 1940. Because
prairie dogs did not evolve with the bacteria,
they carry little immunity to fight off the disease.
¡°The plague bacteria is a non-native invasive
species that devastates prairie dogs and other
wildlife species. We¡¯re not attempting to upset
nature¡¯s balance with these treatments. We are
working to restore balance in the environment
and reduce the risk of major plague outbreaks
in prairie dog colonies,¡± Tripp said. ¡°We lose a lot
of resilience in the environment when we lose
Controlling plague in prairie dogs may also help
limit potential exposure to people and their pets.
In 2010, CPW biologists started dusting some
burrows in the Gunnison Basin with an insecti-
cide that kills fleas. The experiment has worked.
In some cases, nearby colonies that were not
dusted were wiped out by plague while colonies
that were dusted remain healthy. Biologists also
said that they¡¯re seeing many more prairie dogs
in more areas in the basin this year compared to
five years ago.
Although the insecticide is not harmful to other
species, applying it is labor intensive and expen-
sive. For dusting to be effective every burrow in
a colony must receive an application annually.
A potentially promising treatment is the oral
Colorado State University Identifies
Natural, Plant-Produced Herbicide
Fort Collins, June 25, 2014: Scientists have
speculated for decades that spotted knapweed
is able to spread over large areas because of a
secret weapon, an ability to release a chemi-
cal that kills surrounding plants. Until now,
they have never been able to put their thumb
on the phenomenon, but recently a Colorado
State University horticulture professor identi-
fied and isolated the chemical for the first time.
What¡¯s more, they are using the chemical as a
completely natural and environmentally friendly
herbicide to kill other weeds.
The discovery and isolation of the chemical,
called catechin, within spotted knapweed may
revolutionize the war against weeds for home-
owners and farmers.
¡°For years, scientists have talked about spot-
ted knapweed releasing this chemical, but they
couldn¡¯t find it in the soil because it was almost
impossible to separate from all the other com-
pounds that naturally occur in soil,¡± said Jorge
Vivanco, assistant professor of horticultural bio-
technology at Colorado State. ¡°We looked for it
in the plant. Spotted knapweed releases catechin
into the soil through its roots.¡±
Now that catechin has been identified and iso-
lated, and scientists can capture the chemical
in the Department of Horticulture¡¯s laboratory,
Vivanco and a team of researchers at Colorado
State are investigating a wealth of applications
for the chemical. They have discovered that the
weed produces two types of catechin that are
the same chemical compound but the mirror
image of each other in their structure. One has
anti-bacterial properties and the other acts as a
The chemical acts as a natural herbicide to most
other plants, although grasses and grassy-like
plants, such as wheat, display some resistance
to it. This discovery alone holds much potential.
For example, it may mean that specific amounts
of catechin could be used on lawns to kill weeds
without killing grass or on wheat without damag-
ing the crop. The chemical also is environmental-
ly friendly and has existed in the soil for decades.
Catechin kills other species of knapweed, such
as diffuse knapweed, which also is a noxious
weed. It is fatal to spotted knapweed only when
manually inserted into its cells in a laboratory.
In nature, spotted knapweed cells do not permit
catechin to reenter the plant once the chemical is
produced and released into the soil.
¡°It is a clever root to produce, secrete and
protect itself from this chemical,¡± Vivanco said.
¡°There are only small amounts of catechin inside
the root at any given time; it secretes it as it
The Colorado State team has found that spraying
catechin on plants or adding it to soil is as ef-
fective as 2,4-D against pigweed, lambs quar-
ters and other common weeds. Catechin usually
kills cells within the plants in an hour and kills
the plants in about a week, but the team still is
investigating the length of time that it remains
active in the soil to prohibit plant growth. The
researchers are working with commercial com-
panies to make spotted knapweed catechin spray
available to consumers within a year or two.
Colorado State researchers also are working
to transfer the genes that produce the natural
chemical into other plants to give them a built-in
defense mechanism against weeds.
Perhaps one of the most promising applications
of the discovery is the fact that spotted knap-
weed has such a complex defense mechanism.
Spotted knapweed immediately begins to pro-
duce and release chemicals at the slightest hint
of a threat or stress. Just tapping its leaves auto-
matically activates the plant¡¯s chemical response.
The funding for these projects comes from Colo-
rado State University¡¯s Invasive Weeds Initiative.
For more information about this story and other
related Colorado State projects, visit Colorado
State AgNews at: www.agnews.colostate.edu
Natural Weed Killer Discovered
sylvatic plague vaccine, Tripp said. De-
veloped by the U.S. Geological Survey¡¯s
National Wildlife Health Center, the vaccine,
still in the experimental stage, works well in
the laboratory. It is administered in a cube
flavored with peanut butter. The baits also
contain a red dye that adheres to animals¡¯
coats which helps researchers track the
prairie dogs that eat the bait. This is only
the second year that the vaccine has been
tested in the field in Colorado. Longer term
monitoring will be needed to determine its
¡°So far, we¡¯re encouraged by the results and
we are optimistic that the vaccine will be ef-
fective in limiting future plague outbreaks,¡±
In the Gunnison area, four prairie dog colo-
nies are being used for vaccine testing. Two
colonies are receiving the vaccine bait, two
are receiving no treatment. In Teller County
the test is being conducted with two colo-
The vaccine is also being tested in Arizona,
Montana, South Dakota, Texas, Utah, and
Wyoming. The experiment will continue for
another two years and is a collaborative
effort among more than 30 federal, state
and tribal agencies and nongovernmental
In Colorado, the vaccine research in Gun-
nison¡¯s prairie dogs is occurring on public
land, state wildlife areas, BLM and National
Snow Science in the Uncompahgre Watershed:
Monitoring Mountain System Change, Presented
by Chris Landry, Center for Snow & Avalanche
Studies, Jul 30, 7-8p, Montrose Regional Library
Meeting Room, 320 S 2nd St, Montrose.
Chris will present the status of his studies of
the effects of wind-blown dust on the tim-
ing, duration and rate of mountain snow melt.