Koalas’ fur is especially built in such a way that it quickly loses rain water whenever a koala experiences or gets a rainy exposure. Usually rains are very scarce in Australia; therefore, Koalas’ numbers of rainy experiences will also be limited as well in terms of their numbers.
However, during the winters, when the areas are very cold, any rain and the presence of its droplets on Koalas' bodies will further bring more cold as well for the Koalas. Koalas’ fur in such a situation is built in such a way that it quickly releases water whenever; it is being poured on to the fur of the Koalas.
Therefore, Koalas’ fur does not absorb any water and helps the Koalas from being suffering the cold. Since Koalas have lesser energies, therefore, they will never want themselves to burn their calories to produce heat against the coldness of the body. Having water on the fur and skin would have further demanded caloric energies from the Koalas to maintain their body temperatures.
But since Koalas have very limited amount of energy, therefore, they would not prefer to lose their energy no matter what (as a natural instinct). In such a situation if they have a fur that quickly releases water would certainly proves out to be highly essential, otherwise, if this fur would absorb water, the Koala will feel cold and it will has to decompose food and produce caloric energy to resist against the cold. Remember Koalas always prefer external heat that will always put them in a situation to maintain body temperatures during the winter seasons. Therefore, Koalas’ fur is essential in this regard.