Student Questions& Answers Phascolarctos cinereus

1. How do Koalas live in captivity? Koalas do quite well in captivity and are usually kept in semi-closed cages of about 4m by 5m (12ft by 15ft).

2. Are Koalas born with their eyes closed? Yes. Koalas are marsupials. This means that they are born the size of a jelly bean and then crawl into their mother's pouch where they suck onto their mothers teat - eyes closed. They develop here for about 4 to 5 months before their eyes open. This is the main difference between marsupials and other mammals - they do most of their growing outside in a pouch rather than inside their mothers.

3. What do baby Koalas eat? Mothers milk for the first 6 to 7 months. After that they start eating gum leaves.

4. What kind of diseases can Koalas get? Your dad will tell you more about each of these:
   1. Chlamydia
   2. Conjunctivitis
   3. Cystitis
   4. Leukaemia

5. Are there different kinds of Koalas? If so, what kinds? There is only one species but two sub-species: The northern and southern koalas. The southern koalas have longer brownish fur. The northern koala has shorter gray fur.

6. What does a Koala do during their day? Koalas sleep for about 20 hours a day - up a tree. They spend the rest of the time eating and occasionally moving around.

7. Do they have any predators? If so, what are they? Not many. The dingo (a dog) and some of the larger eagles kill koalas but humans are the biggest problem. We rob them of their habitat by building suburbs and cutting down their trees. There are some good news stories though. In some suburbs, koalas are treated like royalty but alas, even so, our cars run them over when they cross the street. Years ago, 3 million - that is 3,000,000 - koalas were shot for their fur. Today there are only about 40,000 to 80,000 left. Homo sapiens is a vicious predator.

8. 8. Do Koalas stay in groups? If so, how many in each group? Koalas live in populations which size is determined by the available habitat. If you take one away from its area, it will travel long distances to walk back to its own area. This is a problem when taking a group of koalas out of an area because a suburb or shopping centre or golf coarse is being build in their area. Many get killed crossing streets going home. They are not highly social animals like a troop of baboons and only interact during breeding time.

9. Do Koalas drink water? If not, why? Yes occasionally but the gum leaves they eat contain water as well so they don't need as much other water.

10. If a zoo were to purchase a Koala, how much would it cost? Why? Here in Australia, between $3000 and $5000. If you want one overseas, you will have to convince the Australian authorities that you will also have enough gum trees - or the right types - to feed them.

11. Do they have good eyesight? Not better or worse than us. Chlamydia and Conjunctivitis can blind them.

12. Is their eyesight better in daytime or night? They see well at night but are not true nocturnal animals. They are sometimes active during the day.

13. Are Koalas friendly animals? In the wild you can go up close to a koala and it will simply look at you without getting upset. Spotting them in the wild is an art because they spend most of the day sleeping in a tree top so you have to walk in the bush looking up - and stumbling over rocks and falling down holes in the process! If you try to catch them or touch them in the wild, they will scream loudly with a "Blaaaa" type sound. They can claw you pretty badly and bite a hole in your arm if your not careful. I guess it's like trying to catch a wild cat. In captivity they grow very tame.

1. What kind of koalas do you work with? There are two types of Koalas: the southern koala found in Victoria and Southern New South Wales. Here in Queensland we deal with the smaller Northern Koala.

2. Do different types of koalas have differences, besides appearance? The two types of Koalas are of the same species - that means they can interbreed. The southern koala is about 50% bigger, has a fluffier fur and is browner in colour.

3. Do the shagginess of the ears of New South Wales and Victoria koalas have any real usage? Yes, it is much colder down south - especially in winter when it snows in some places. Up north the koalas live in a sub-tropical climate - nice and warm so they don't need the thick coats - not just the ears.

4. How have their "extra thumbs" helped koalas adapt to Australia's eucalyptus trees? Koalas have 5 digits on each foot - like us. The toes are divided into 2 and 3 so that it can grip the trees better. A koala is a heavy animal for it's size - much heavier than a possum. It needs a better grip - especially for climbing the smooth bark trees.

5. How do koalas' sensitive noses help them tell if eucalyptus leaves are good to eat or not? Eucalyptus trees protect themselves by having toxins in the new growth - especially those trees adapted to arid regions and poor soil. The koala knows this and will not dive into its food. A koala will pull down a branch and sniff the juicy buds before deciding to eat or not to eat it.

thank you for taking the time to do this.

Genevieve

Pleasure love - let us know how the assignment went.

Johanna Griffith

Dear Joanna,

Thank-you for your inquiry about Chlamydial infection in koalas. Although at some time in the future we will be including a detailed section on Chlamydiosis in koalas on our web site, I have not yet written it. There are a number of papers on Chlamydial infection in koalas in veterinary journals which should be easy enough for you to find in your library. I can also send you photocopies of some other articles including review articles if you E-mail us your postal address. However here is some information which you may find helpful:

Chlamydiosis is the most common infectious disease of koalas. It is found in all states in which koalas occur naturally and in some populations infects up to 70% of koalas (possibly more). A number of wild populations are free of Chlamydia including French Island (Victoria) and Kangaroo Island (South Australia). Both of these island koala populations suffer koala overpopulation problems. Contrast this situation with that on Phillip Island (Victoria), where Chlamydiosis is common and you can see that in certain situations the disease is an important factor in regulation of population numbers. In large populations of koalas in good habitat, diseases such as Chlamydiosis tend to fall into a natural balance with the population, causing morbidity and mortality in relatively few individuals, with a proportion of animals developing immunity to disease. In populations under severe urbanization pressures or in degraded habitat, or where overcrowding into inadequate habitat occurs, Chlamydiosis may become far more significant. In these situations we can expect morbidity and mortality from the disease to increase.

Two strains of Chlamydia are thought to be involved in the disease in koalas: Chlamydia pecorum (the most important) and Chlamydia pneumoniae. Recent research into the DNA sequences of these strains suggest that infection of koalas may have originated from domestic animals, such as sheep and cattle, however further work needs to be done to clarify this. Chlamydiae are obligate intracellular parasites causing lesions in affected tissues referable to chronic active inflammation. Most common conditions in koalas are "pink-eye" - keratoconjunctivitis, dirty-tail - urinary tract infection, and infertility - principally in female koalas.

Keratoconjuctivitis - can be unilateral or bilateral, usually begins as slight serous discharge which progresses to muco-purulent. The discharge can be quite copious and cause the eyes to seal shut, as well as causing crusting and peri-ocular dermatitis. Infection with secondary bacteria is common. Blepharospasm is common from the early stages of infection. As the disease progresses there is granular proliferation of the conjuctivae causing chemosis, and progressive oedema and scarring of the cornea.

Urogenital tract infection is also common and may occur with or without keratoconjunctivitis. In males there is chronic inflammation and scarring of any epithelial surfaces in the urogenital tract and in severe cases the infection can progress to nephritis. The lesion is especially apparent in the bladder, where there is marked thickening and sclerosis of the wall, ulceration of the mucosa with secondary bacterial infection, and frequently thick caseous casts in the bladder. In females, the most common lesions are cystitis and cystic ovarian bursitis. Secondary infections and abscess formation in the uterus is also common. Chronic cystitis in both males and females results in incontinence and urine staining of the fur around the rump (dirty-tail). In severe cases this can become ulcerated and flyblown.

Transmission of infection almost certainly includes the sexual route, but other modes are not yet determined. The disease is rare in koalas under two years of age. A number of factors may influence the expression of the disease, including nutritional and physiological stress, immunosuppressive retroviruses and genetic make-up. Spontaneous recovery of wild koalas suffering clinical disease has been observed. However there is still much that we do not know about the disease, and we certainly do not understand its full significance in wild koala populations.

I hope this information is of some use to you. Please send us your postal address if you would like us to send you some articles.

Regards

Jon Hanger
Veterinary Surgeon

Koalas protect themselves by living in trees - up where dingoes and other land based predators cant reach them.

That is about the best they can do. Keep in mind that Australia has no native felines - cats - no lions, pumas, tigers, leopards or Cheetah so the koala is relatively safe. Australia also has no native Canis - dogs or wolves. Australia has no native foxes. The Dingo is a wild (feral) dog that was introduced by the Aboriginal people who came from the North (Indonesia) so the dingo is a relatively late arrival(40,000 years ago) and does not climb trees.

Up in the trees the koala only has to avoid eagles and pythons.

With the arrival of European settlers, cats, dogs and foxes were introduced. Luckily for the koala, Europeans did not introduce ferrets that could climb trees.

The poor fellows are vulnerable to fires. Bush files started by aboriginals, lightning or more recently, Europeans, reek havoc amongst the poor creatures who are burned to death up in their trees. The fires usually spread faster than a koala can run.

The biggest thread to the koala is not disease or predator but loss of habitat due to farming and urban development. To solve this problem, parks are set aside for koalas. All new development need to pass an environment impact study before it is allowed. Once, not so long ago, the Queensland government wanted to build a road that would go through a koala colony. The Government was defeated at the next election and the road was never build.

In some areas, koalas are trapped in small pockets because suburbs were developed all around them. These koalas were relocated to wildlife parks under government protection.

Koalas were settled on Kangaroo island on the South Australian coast. They flourished so well that the island became over populated and large numbers had to be relocated.

It is just a matter of degree - threatened means that their numbers are declining and we better do something about it. There could be thousands of individuals. The number of koalas is estimated between 40,000 and 80,000 so they are safe - provided things don't get worse.

Endangered means that if we do not act quickly, the species might go extinct (Panda bear, Asian Tiger etc). Their numbers have been reduced to a few hundred or a few thousand. Once the numbers get to below a hundred individuals, there might not be enough DNA diversity to sustain a growing population without in-breeding and resultant defects.

Why are koalas only found in Australia and nowhere else?

Australia, Antarctica, Africa, India and the Americas were all part of a super-continent called Gondwanna Land. The continents broke away from one another and drifted apart. If you take a map and cut out the continents, you will see how they all fit together. South America's bulge easily fits into the gap in West Africa where The Congo is.

Australia was the only major landmass that had no land connections to other continents. North America had a land bridge connecting it to Asia; Africa is connected to Asia and Europe. When human-like creatures evolved in Africa, they could spread all over Europe and Asia and into the Americas.

Because of its isolation, Australia developed a unique set of plans and animals. To this day, marsupials, including the kangaroo and koalas, are found nowhere else on Earth. They evolved in Australia and were protected from competition from other mammals through isolation.

Happy hunting for the other facts. Take the links on the left-hand side of the koala page. Click on the koala fact sheet and other links and you will find all you need.