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Research Questions Why the koala was listed as a threatened species by the Australian Government in August 2012? How can we improve this situation?Some of the aspects to be investigated are: Disease, Climate change, Human impact.
Basic Koala Facts Koalas usually eat eucalypt leaves but some koalas will eat other plants. Rarely do koalas have to drink to quench their thirst as eucalypt leaves contain a reasonable amount of water. The leaves of the eucalypt tree are high in fibre but low in protein. Because the eucalypt leaf contains oils and other chemicals, it is inedible to some other mammals but the Koala is well adapted to them. Koalas sleep in the trees in the day, feed at night and are most active just after sun set, therefore making them nocturnal.
Basic Koala Facts The breeding season for koalas is summer. Female koalas normally give birth to one joey a year. A joey usually stays in its mothers pouch for 7 months, then after another 5 months is completely independent, then usually leaves its birth place at 18 months. Females become sexually mature when they are 2 years old, but males mature at 3-4 years of age. Koalas are the only tree dwelling marsupial without a tail.
Koalas: Threatened Species In August 2012, koalas were announced as a threatened species since their population is declining rapidly. This is due to habitat loss (most often for urban development), multiple diseases, such as chlamydia and leukaemia, getting killed by dogs and climate change (too hot and dry, causing dehydration and overheating). They are on the threatened species list in NSW, ACT and QLD, but are not yet threatened in Victoria. SAVE THE KOALAS
Diseases Disease is one of the problems playing a part in koala numbers dropping dramatically. Chlamydia is a sexually transferrable disease that stops the koala’s ability to reproduce. Leukaemia (a type of cancer), other bone marrow disorders and problems with their immune system are affecting the koalas. It is not known for sure, but a retrovirus may be responsible for some of the diseases and other affects in koalas. A retrovirus is a virus that penetrates into the host’s DNA and is replicated as part of the DNA.
Genetics In the 1890s, some healthy joeys were taken to French Island off the coast of Victoria As this koala population bred, they eventually ran out of food, so they were translocated back to the mainland, which repopulated mainland Victoria’s koala colony. The French Island colony became overpopulated again and female koalas were given an implant to affect reproduction but the implants possibly had a negative effect on their health. Due to inbreeding from the French Island koalas, genetic effects are suspected to be reducing the health of the Victorian koalas.
Climate ChangeWill koalas become extinct in some areas due to climate change? In Gunnedah, NSW, there were really bad heat waves in 2009. Koalas were lying dehydrated at the bottom of the tree. Koalas reached out for help when environment officers sprayed their noses with water. Gunnedah has been replanting with koala friendly trees to try and help protect the koalas. http://www.abc.net.au/4corners/stories/2012 /08/16/3569231.htm Four Corners Episode Koala Crunch Time Time for Gunnedah section:36.31 Gunnedah
Habitat Loss and Translocation Development is major threat to koalas, destroying lots of their habitat. On the Gold Coast, koalas are losing their homes (trees) to development for houses, roads and shopping centres, as eucalypts are being cut down in large numbers. Scientists and koala specialists are having to resort to translocating the koalas to save them from the bulldozers. Translocation is stressful for the koalas and is not always successful, but it’s better than leaving them to fend for themselves against the bulldozers. Some of the development causing trouble for the koalas was approved many years ago, when the koalas weren’t in so much trouble and it can’t be stopped now. The Queensland State government says the development is ok, but the Federal Government says more needs to be done to protect the koalas.
Habitat Loss and Translocation (continued) Clearing land for mine sites is also affecting koala habitat. Some people think that when koalas run away from land clearing, they scamper away to safety, but the truth is they usually die.
Saving the KoalaHow can we save the koala? We can donate to koala preservation associations such as the A.K.F. (Australian Koala Foundation). People from koala-populated areas can plant eucalypts for koalas. We can spread a wider understanding of the danger the koalas are in and convince other people to support the koalas.
References http://wdhq.com.au/oldsite/koalasdistribution.html, accessed 2nd September, no update date but map from 2004. http://www.fnpw.org.au/plants-a-wildlife/land-mammals/koala , accessed 2nd September, updated 2012. http://www.abc.net.au/4corners/stories/2012/08/16/3569231.htm, 4 corners Episode Koala Crunch Time by Marian Wilkinson and Morag Ramsay, accessed 8th September, updated 21 August. Pyers, G. (2005) Life Cycles of Australian Animals, Binara Publishing. Resnick, J. and Davis, J. (2001) Kolah the Koala, True-to-Life Books.
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