Ari Pannor-Brown
2/6/11
Period 6 &7
Language arts & science
Exotic Rabbits
Rabbits are perceived as cute, furry, little animals that seem harmless; however,
that does not apply in Australia. Rabbits have been one of Australia’s biggest problems
for over two hundred years because they are exotic. Australia is an isolated continent,
and as a result the environment is completely different compared to Europe. Because of
this rabbits do not have natural predators or diseases in this environment, causing their
population to expand. Naturally this causes changes in the ecosystem. But those
ecological changes are causing economic and environmental disaster, which may be
reversed by introducing new predators or viruses into the rabbit population of Australia.
The scientific cause of Australia’s problem is the rabbit is basically from a
different ecosystem; in short it is an invasive species, as said by the department of
environment for the Australian government. Earth has many biomes consisting of their
own environments, with terrain ranging from deserts to glaciers. Life can evolve and
adapt to form ecosystems to work with an environment. If an ecosystem affects another
it will change, but in the process it will lose its bond with the environment because the
change was for the other ecosystem. The closer the affecting ecosystem is, the less of
a change, because the transition of these environments are greater with larger distance
between them. Rabbits are an effect from the European to Australian ecosystems.
Because Europe and Australia are so geographically far away, the effect causes big
changes. To undo these unnatural migrations the government is looking towards
unnatural solutions.
There are many possible solutions to reduce the huge population of rabbits; one
of the most common is rabbit hemorrhagic disease (RHD). RHD is a highly infectious
and often fatal disease that affects wild and domestic rabbits. It has been used in
Australia before, but failed. The Foundation of Rabbit-free Australia is an organization
that promotes and supports the continuing research and development for rabbit
population control. RHD Boost is the most recent research program trying to improve
and evaluate the RHD virus. The program includes finding RHD strains that are lethal to
rabbits immune to CZ 351, the RHD strain previously released. The project is currently
looking into a European RHD Virus to be a candidate for Australia. Dr Peter Kirkland is
the leader of RHD Boost, which is taking place at the Elizabeth Macarthur Agriculture
Institute. RHD is the most recent virus but it is the first to be researched and tested in
Australia.
Before RHD was studied, this issue has had a long history of attempted
solutions. According to the Australian government, this problem first started in 1788
when the first fleet from Great Britain came to Australia and brought with it the
European rabbit. Used for food and fur, some rabbits escaped into the wild, and once
there the population exploded. As their numbers grew the rabbits moved and invaded
more land until they covered all of Western Australia. By 1907 the Australian
government recognized this and built a long anti-rabbit fence between south and west
Australia to stop their migration. However, by the time it was finished rabbits had
already crossed into the area the fence was protecting. At this point the government
looked into other solutions.
There were many ideas to stop this, but the most popular at the time was the
Myxoma virus. This virus causes Myxomatosis, a deadly viral infection, to form in
rabbits. It was first suggested by a Brazilian scientist named De Beaureparie Aragao in
1918, but was rejected because it did not provide the desired results (Think quest
library. org). In the late 1920s the Australian government reopened the project to the
Commonwealth Scientific and Industrial Research Organization (CSIRO). The leaders
of this project were Dr Jean Macnamara, Richard Shope, and Charles Martin. The first
trials of the virus were run in Britain, Denmark, Sweden, and southern Australia, but
were unsuccessful because the conditions did not allow the virus to spread properly
(Article from the Australian Academy of Science). After further development for the
virus, in 1950 CSIRO claimed 5 different field sites in the Murray River valley in Western
Australia. They believed that these areas would cause the experiments to be
successful.
The CSIRO experiment consisted of infecting a small group of rabbits and
placing them in five different locations in the Murray River valley. This experiment was
different from the previous trials because large numbers of rabbits go to the river to get
water, causing the virus to be easily spread around from breading. At first the trials
appeared to be failures because the rabbits were not breading enough. However in
early 1951 the Murray River had heavy rains that caused the mosquitoes to breed more.
With the additional mosquitoes the virus was carried from infected to uninfected rabbits
from sucking their blood. According to an article published by CSIRO, within 3 years the
disease had been carried to all parts of Australia and the rabbit numbers were
drastically reduced.
However this did not last, the evolutionary selection processes was working in
the rabbit population. If one rabbit in a thousand had a natural resistance to the Myxoma
virus, it alone would survive to leave offspring a greater chance of surviving the virus.
This natural selection happened, causing the rabbit populations to recover and inherit
immunity to the virus. Today if the virus was released again, it would only kill 50% of the
rabbit population and cause a stronger immunity. In conclusion, the experiment failed
because natural selection was not anticipated to work as fast or at all. The Myxoma
virus proved to be a dead end, but it changed how the society of Australia will treat
these experiments.
Despite the fact that rabbits are destroying the environments, they are still a
resource. Rabbits were originally brought there for food and fur and can still provide that
for people. That said the Australian society and economy was very dependent on
rabbits; there were many protests against reducing their population (article from
sutite101.com). In fact, one of the reasons why the Myxoma virus was rejected in 1918
was because the Australian authorities were concerned about the losses of the rabbit
meat and fur industries. When CSIRO reopened the project the government still
prevented them to test the virus in Western Australia until 1950. But as time passed the
rabbits caused more trouble for plant life and farming industries, costing millions of
dollars per year for the economy. Now the government and society of Australia better
under stands how this problem will continue to get worse and are more accepting of
experiential solutions.
Today this problem continues to grow, and so far nothing is stopping it. Although
scientists have been turning to genetic viruses, there are other possible solutions as
well. One is introducing a natural predator of the rabbit, such as foxes, to reduce their
numbers. The problem with this is that it’s risky because if the predators cannot be
controlled then they will become an invasive species as well. They will shrink the
population of the rabbits but theirs will go up. That is why genetic engineering has had
so much research being done, at the moment it is the only solution that will cause the
least amount of damage to the ecosystem. It’s hard to believe that a single creature
can cause such deviation and destruction.
Works Cited
"Feral animals in Australia." environment.gov.au. Department of Sustainability, Environment,
Water, Population and Communities, 8/12/2010. Web. 14 Feb 2011. H
http://www.environment.gov.au/biodiversity/invasive/ferals/index.html
"The history of myxoma virus in Australia." NOVA. Australian Academy of Science , 1997. Web
14 Feb 2011. http://www.science.org.au/nova/001/001box02.htm
"Control of Introduced Species." Questacon. Commonwealth of Australia , 2009. Web. 14 Feb
2011. http://www.questacon.edu.au/indepth/clever/control_ferals.html
Massaro, Andrew. "The Wild Rabbit in Australia." EzineArticles.com (2007): n. pag. Web. 14 F
Feb 2011. http://ezinearticles.com/?The-Wild-Rabbit-in-Australia&id=2824667
"History of Rabbits in Australia." thinkquest.org. N.p., 2004. Web. 14 Feb 2011.
http://library.thinkquest.org/03oct/00128/en/rabbits/history.htm
"Current Research." RFA. Foundation for Rabbit-Free Australia Inc., 2010. Web. 14 Feb 2011.
http://www.rabbitfreeaustralia.org.au/current_research.html#rhd_boost