At this time males will bellow more frequently as their mating calls. Once a female is conceived, the baby is after 35 days. Which is a very short gestation period. It comes out of the mother 2 centimeters long, and it makes it's way to the pouch all by himself. The teat then swells, and fills it's mouth, which prevents the body from getting dislodged from it's food source.
Koalas have a very slow metabolic rate, because they mostly sit in trees all day.
That also allows them to retain food in their Digestive system for a long time, maximizing the amount of energy being able to be extracted. The digestive system of Koalas, also detoxifies the poison inside of the eucalyptus leaves that would kill other animals. It does this by having an enlarged Caecum of the gut, in the Caecum, there is a large bacterial colony, that aids with the leaf digestion. Koalas move with an awkward gait, on all four legs, and can also run. In a couple of occasions they have even been spotted swimming, but this is very rare.