Koalas do live a reasonably long life of around 12 years to 16 years. In fact female Koalas live longer than the male Koalas and live for 16 years or more. On the other hand, male koalas usually die at the age of around 16, which is 4 years more than the average age of the male koalas.
For Koalas living for almost 12 to 16 years is almost normal as compare to many other mammals. For example monkeys live for this age as well as many other animals such as baboons, tigers, lions and even dogs as well. Therefore, this average age of the koalas coincide with the average ages of many other mammals as well.
Koalas in Queensland live less as compared to the Koalas within the Victorian territory. The Koalas in Queensland die earlier than their average age, because there is less availability of the food resources for the koalas at that area, while within the Victorian territory, the food availability is higher, and as a result of that the Koalas average age has been greater.