Our koala joeys are now 12 months old, it was only a few months ago they were just starting to learn how to climb trees all by themselves like a big koala. Now they are fully independent and are out in the outdoor exhibit away from Mum enjoying play time with some of the other younger males.
Our joeys from the previous season are just over two years old, and it’s at this age that they start to sexually mature. At the age of two they’ll start to develop a scent gland on their chest and start to learn how to bellow, both of these characteristics they’ll use to help find females that they will mate with. On our younger males their scent gland is quite small, and as they mature it will become larger and smellier. They use their scent gland to rub on the trees to mark their territory and let females know they are in the area. While it’s possible a koala can breed as young as two years old, out in the wild it is unlikely that they’ll successfully breed until about 4 years of age because they have to compete with mature males.
When koalas reach sexual maturity, they will also start to learn how to do a vocalisation known as bellowing, this will tell other males they’re in the area and it’s his territory and it will also attract females who are ready to breed.
Females will reach sexual maturity from about 18 months to two years of age and this is when they’ll start having oestrous cycles. So when a female is in oestrus she may display behaviours such as vocal bellowing like the males do, as well as movements such as ear flicking or jerking which is usually in response to a male. If a female is not interested in a male, she will usually scream back at him at what’s known as a vocal rejection, and it pretty much means a firm no.
Koala breeding season is generally between September and February. So next time you’re in for a visit, keep an ear out as you might hear some bellowing, and let your imagination tell the rest of the story.