Animal Diaries Archive

The birth and development of a joey koala

24 February 2006

At Australia Zoo, our koalas are keeping us busy! Currently we have five females with pouch young as well as three maturing joeys from last year's breeding season.

As a marsupial, koalas are very interesting animals in regards to their breeding behaviour and characteristics. After a successful mating, the female will become pregnant for a gestation period of around 34 to 36 days. The birth can be very short and the underdeveloped young have a very big journey ahead. At approximately one inch in length and weighing no less then one gram, the joey climbs from the birth opening up the underbelly of the female and into a pouch. The koala pouch is backward-facing, with an opening close to the hind legs. The joey attaches to one of the two teats and will commence suckling of the mother's milk.

When talking about pouch young we are referring to young between the age at the time of birth, and up to approximately six to seven months. At this time the young are developing rapidly and do not venture from the safety of the mothers pouch. As the joeys continue to mature they move out of the pouch onto the underbelly, then are carried around on the mother's back. At approximately 12 months, the joeys have become totally independent and are feeding by themselves away from the mother. But a koala continues to grow. Full reproductive maturity and maximum growth is reached at three to four years of age.

The three mature joeys that we have are now nearing 14 months old. Their names are Seanna, Chanel, and Jaffa. You can see them in our Koala Island enclosure nest time you visit us. We hope to see you soon.