Female koalas usually start breeding at the age of 3-4, and usually only breed one cub a year. However, not all wild female koalas breed every year, and some female koalas breed only once every 2-3 years, which mainly depends on the age of the female koala and the quality of its habitat. The average life span of wild female koalas is about 12 years, which means that a female koala can only breed 5-6 koalas in her life.
The pregnant period of koalas is only 35 days. At birth, the koala was only 2 cm long and weighed less than 1 g. It has no hair, no sight or hearing, and looks like a pink fudge.
After the koala is born, with its well-developed sense of smell and touch, strong forelimbs and claws, and innate sense of direction, it will climb into its mother's belly pouch independently without her mother's help. Once safely in the pouch, the koala will firmly grasp one of the two nipples, thus ensuring the food source needed for the koala's growth. At the same time, the female koala will contract the muscles of the pouch to prevent the baby koala from falling out of the pouch.
In the first six or seven months, koalas only ate breast milk and never got out of the pouch. During this period, koala's eyes, ears and fur will gradually develop. At about 22 weeks old, the koala opens its eyes and pokes its head out of its pouch to see the outside world. At 22-30 weeks, the female koala will excrete a semi-liquid soft food from the intestine for the young koala to eat. This kind of food is very important, not only soft, koala is easy to eat, but also nutritious, containing more water and microorganisms, easy to digest and absorb. This kind of food will accompany koalas through the important transition period from breast milk to eating eucalyptus leaves until koalas can eat eucalyptus leaves completely, just like human babies will eat porridge semi-liquid food for a while before eating solid food.
When the baby koala leans out from the mouth of the nursing bag and eats the semi-liquid soft food discharged from the intestine of the female koala, it will stretch the mouth of the bag backwards. So strictly speaking, it is not accurate to say that the female koala's pouch is open downwards or backwards.
In the process of feeding semi-liquid food, koalas will gradually climb out of the pouch until they are completely lying on the mother koala's abdomen to eat, and finally start eating fresh eucalyptus leaves and climb on the mother koala's back to live. Of course, koalas will continue to feed on the breast milk in the pouch until about 1 year old. However, the little koala's body is getting bigger and bigger, and it can't put its head into the pouch, so the female koala's nipple will stretch and protrude from the open pouch. This koala will continue to live with the female koala until the next baby koala is born. At this time, the little koala had to leave her mother and find her own field. If the female koala doesn't breed every year, then the longer the little koala lives with her mother, the greater the chance of survival.
Generally speaking, female koalas live longer than male koalas, because male koalas are often injured in the battle for spouses, and they need to move a greater distance, because they need to maintain a larger area, risk more car accidents and being bitten by dogs and other animals, and occupy a larger barren soil eucalyptus forest. It is misleading to use the average age data of koalas, because some koalas can only live for a few weeks or months, while others can live for a lifetime. Koalas living in a quiet environment will live longer than koalas living in the suburbs of cities. It is estimated that the average life span of adult male koalas is 10 years old, but the average life span of some sub-adult koalas scattered along highways or residential areas is only 2-3 years old.
Once eating eucalyptus leaves, koalas grow faster and stronger, and at the same time become more dangerous. First, koalas hold their mothers' bellies to keep warm and hide, but sometimes they ride on their mothers' backs. Finally, it will walk a short distance from its mother. These behaviors put koalas at risk of falling and being injured.
12 months old, koala left her mother and started her own home, which made koala's life more difficult because she had to find her own territory. There, there must be eucalyptus forests that can provide delicious food for koalas, and they must be close to other koalas. It is best to have some safe places to keep them away from forest destruction, car accidents and dog attacks. The Australian Koala Foundation estimates that at least 4,000 koalas die every day from car accidents and dog attacks, and habitat destruction is the biggest threat to koalas' survival.