Some eucalyptus tree produce a gas that burns well, so forest fires in Australia can often travel quickly. Bush fires are one of the biggest killers of koalas, because the animals cannot move fast to avoid the approaching flames.
Moisture evaporates from the leaves of plants and later falls as rain. The more the land is cleared of trees and bushes, the less it rains, and the risks of drought and fire become greater.
Bushfires are now a major threat to koalas because much of their habitat is so broken up. Small, isolated koala populations can easily be wiped out by a single bushfire.
After the fire has died down, koalas’ paws can easily be burnt when they come to the ground to move to another tree. Because there is less ground cover after a fire, koalas are also more at risk from predators, such as dogs. Many often starve because their food supply can take several weeks to regrow.
The intense bushfires around Sydney in January 2002 occurred during a drought, and were one of the worst natural disasters to hit New South Wales for a century. These fires had a disastrous effect on koalas and other wildlife. Very few animals survived the fires, which lasted for around three weeks. Now that this area bush is reduced, it is more likely to be more seriously damage by large, intense fires in the future.
Tree dieback causes trees to die rapidly, often in large numbers like these. Although it is becoming more common in rural areas, Dieback can be preventing by good farming techniques.
Disease threat to Koala Bears
Some koalas colonies have been harmed by the disease Chlamydia and other illnesses. Because of these threats, koalas are listed as vulnerable in two of the four Australian states that they inhabit. In one state, they are listed rare.
Diseases are natural part of life for koala. One common disease, Chlamydia, has been present in koala populations for many years. Scientists believe that it could act as a natural population control. This means that it is generally harmless in healthy koalas that have plenty of food and shelter, but it affects weaker animals or those that are under stress. Coping with loss of habitat and other difficulties can cause stress or upset in animals. Chlamydia is occurring more frequently in koalas today because they are under more stress. The disease causes various problems, including eye and lung infections. It causes some of the weaker animals to die, leaving the stronger ones to continue breeding.