In A Nutshell
The adorable koala spends the majority of its life snoozing in the treetops, free from the grasp of most predators. That is not to say, however, that it is an easy life—the koala is subject to a number of diseases, including chlamydia and Koala Immmune Deficiency Syndrome, an AIDS-like infection. The eucalyptus trees where they find their nutrition are highly flammable. Perhaps worst of all, around their sixth birthday, their teeth begin wearing down, leading to eventual starvation.
The Whole Bushel
One of the symbols of Australia is the cuddly koala, a marsupial most closely related to the wombat. The vast majority of the koala’s diet is made up of eucalyptus leaves. As this provides only limited nutrition, the koala spends most of its time sleeping. Once in a while, a koala falls prey to a dingo or a python, but it is a rarity. Unfortunately, there are a number of other factors that come into play in shortening the animal’s life.
Most koalas host blood parasites like Trypanosoma irwini (named after Steve Irwin, the Crocodile Hunter), which can lead to a variety of symptoms, like weakness and anemia, particularly harmful to an animal which is already quite sedentary. They are also subject to disease, particularly chlamydia. This is a different strain than that which affects humans, but can also be sexually transmitted. It causes conjunctivitis and urinary tract infections which can eventually lead to blindness, infertility, even death. It can be cured, but only after a months-long regimen of antibiotics. They also suffer from koala retrovirus, a disease like AIDS in humans, which devastates the immune system and leads to death from cancers such as lymphoma and leukemia. Nearly every koala in the northern part of its range is infected with retrovirus, and the disease is slowly making its way south.
Likely the greatest threat to the koala’s existence is mankind. Urbanization threatens the koala’s habitat, and where it comes into contact with human neighborhoods, the results aren’t often pretty. They are hit by cars, attacked by dogs, and drowned in swimming pools. Global warming, and increasing amounts of carbon dioxide in the atmosphere, has aslo served to lessen the nutritional quality of eucalyptus leaves.
Even in a perfect world, the koala is not designed to live long. By its sixth birthday, its teeth begin to wear down, the cusps on its molars flattening. Eventually, they can no longer chew eucalyptus leaves, and starve to death.
Show Me The Proof
BBC: Koala chlamydia: The STD threatening an Australian icon
ABC Newcastle: Fears for koala casualties after bushfires
Huffington Post: Australia’s Koalas: Threatened By Urban Sprawl, The Marsupial Struggles To Survive