Aaah Spring is in the air, and so are the birds and the bees, inciting love in all of our furry, feathered and winged friends! Unfortunately for the female koala mating is not an experience based on love, but instead practicality. Here I will try to describe some of the unique facts about koala sex and the general life cycle of the South Australian Koalas.
Koalas in South Australia generally mate between September and February when the weather warms up and their activity levels increase. The larger male koalas have a very distinctive bellow that they yell across the trees. Recent studies have shown this bellow has two affects - firstly it lets female know that there are males around and it also helps scare off smaller males so they can avoid the big boss koala of the area and not get into any fights.
Once a male koala spots a female he is very... persuasive... female koalas are stimulated ovulators which means they only ovulate once they have had sex. This also means they are often not that interested in having sex with these big males, no matter how handsome and successful they may be. The male koala grabs onto the females back, and will often bite the scruff of her neck to prevent her getting away. The whole affair lasts around 1-2 minutes, koalas don't have a lot of energy to spare. It generally ends with the female koala giving him a good slap to the face and running off. Although it all sounds a bit cruel its the way of life for koalas, and they know no different, so in the end it works for them and as kept the species going for thousands of years.
Because the female is a stimulated ovulator they have to really 'feel' the sex for it work. To help their body recognize they are being mated the male koala has evolved a spiky forked penis. It is quite the sight to behold, and we've had many a member of the public get a fright the first time they've seen one.
The female koala remains pregnant for around 35 days. The joey makes its way down the middle birth canal of the vagina, there are also two lateral canals in which sperm can travel up to the uterus. Koalas and other marsupials have very tiny uterus's compare to body size since they the joey is born at only 1 gram of weight!
The joey then makes its treacherous journey up the mothers pouch where it attaches to one of two teats. At around 22 weeks of age they start poking their head out of the pouch and start eating their mothers poo - but this isn't any faeces it is a special substance called Pap, which comes straight from the mothers caecum (part of the intestines) and is filled with the good bacteria the baby needs to start digesting the toxic eucalyptus leaf they will eat as adults.
At around 30 weeks of age the baby starts coming out of the pouch more and more and clings to its mothers back. Generally joeys hang out with their mums until around 18 months of age.
Male koalas generally start mating round 4 years of age, although they are sexually mature by 2 years of age. Female koalas will often start having joeys of their own as young as 2 years of age.
So koalas have a pretty interesting life cycle - they are born as tiny jelly beans, then eat their mums poo before becoming adults and leaving. Then the circle of life continues after a less than glamorous mating ritual. I have shared some photos of joeys at various ages - they are so tiny and undeveloped but grow into very cute furry adults!
If you have any questions please ask, and check out the "Vet tails" Facebook page for more photos!
Joey ranging from 2 weeks of age to a fully grown adult male!