The loss and changes to the koalas habitat are the main cause of direct threats to koalas such as being hit by cars, dog attacks, and increases in disease due to stress.
When habitat is removed, or disturbed by roads, agriculture or fencing, koalas’ home ranges are forced closer together, overlapping, with a reduction in size and quality. This increases competition between them, and decreases the amount of time they have to look for food and rest. That means there is a decrease in the overall condition and health of individuals and populations.