Where is Cora?

In Australia, the breeding season of koalas is from August to February. During this period, the male koala will be more active, making a louder and more frequent roar than usual. The same is true of the little koala leaving its mother and starting to live independently. If koalas live in remote areas or near major highways, it will show that this time is also the busiest time for koala nurses, because koalas will increase their chances of injury and illness due to traffic accidents and dog attacks when crossing the road.

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 on the edge of 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.

Koalas' habitat

Koalas inhabit islands on the east coast of Australia, tall eucalyptus forests and inland lowland forests. However, millions of years ago, the koala's ancestors lived in the tropical rain forest, and the koala gradually withdrew from its original habitat due to long-term evolution. Wild koalas will only appear in places suitable for their lives, and there are two important factors. One is that koalas must have tree species (including non-eucalyptus species) that they prefer to eat, and have suitable soil and rainfall to ensure their growth. The other is that other koalas have settled here.

Studies have shown that even if there are known tree species that koalas choose as food, the stability of koala population cannot be guaranteed unless there are 1 and two species that koalas prefer or particularly like in this area.

So that's why it's not a good idea to plant only trees that koalas can eat. It is often a waste of time and energy to neglect planting key tree species in order to restore koala habitat.

Koalas' food and digestion

Koala is a very picky animal. It only eats eucalyptus leaves from Australia for a living. Eucalyptus leaves are particularly high in fiber and low in nutrition, and are also very toxic to other animals. In order to adapt to this low-nutrient food, koalas have evolved a very perfect system and mechanism for a long time. Koala's metabolism is very slow, which ensures that food can stay in koala's digestive system for a long time and digest and absorb nutrients in food to the greatest extent. This low and slow metabolic activity also allows koalas to conserve energy and physical strength to the greatest extent. So we will often see koalas sleep 18-22 hours every day!

Koalas' digestive system is especially adapted to these eucalyptus leaves containing toxic chemicals. It is generally believed that these toxins are produced by eucalyptus to prevent leaf-eating animals from eating leaves, and the more barren the land where eucalyptus grows, the more toxins are produced, which may be one of the reasons why koalas only eat several kinds of eucalyptus leaves, and sometimes even try their best to avoid living in some eucalyptus forests.

Koalas have a special organ for digesting fibers-the intestine. Other animals, such as humans, also have intestines, but compared with koalas' intestines, which are 2 meters long, they are simply not in the same breath. Millions of microbes in the intestine break down the fiber in food into nutrients that koalas can absorb. Nevertheless, only 25% of the food eaten by koalas is digested and absorbed. Because koalas can meet their own needs by absorbing water from food, koalas rarely drink water, although the water content in eucalyptus leaves will be greatly reduced in dry season.

A koala eats about 200-500 grams of eucalyptus leaves every day, and koala teeth are also very suitable for handling these special foods. Sharp long incisors are responsible for clamping eucalyptus leaves from trees, and molars are responsible for cutting and grinding. The gap between the front teeth and molars enables koala's tongue to effectively mix food balls in its mouth. Koalas are very picky about food, even paranoid. In Australia, there are more than 600 kinds of eucalyptus, but koalas are only interested in several of them. In some areas, koalas even eat only one kind of eucalyptus leaves, sometimes only two or three kinds. Of course, there are also some other kinds of leaves, including non-eucalyptus plants, which are occasionally eaten by koalas in very small quantities, or used as mats or sleeping mats.

Different kinds of eucalyptus are distributed in different parts of Australia, so koalas living in Victoria and Queensland may eat completely different kinds of eucalyptus leaves. You can imagine how boring it would be to eat the same food every day, so koalas sometimes try to eat other plants, such as acacia leaves, tea leaves or Melaleuca plants.

Physical characteristics of koalas

Koalas are very suitable for arboreal life. Although koalas do not have obvious tails like kangaroos and other arboreal marsupials, this does not affect their excellent sense of balance. Koalas are muscular, slender and strong, suitable for climbing among branches and supporting their own weight. The front legs are almost as long as the legs, and the climbing strength mainly comes from the developed thigh muscles.

Koalas' claws are especially suitable for grasping and climbing. Rough palm pads and toe pads can help Kao hold the branches tightly, and all limbs have sharp long claws. The forefoot has five fingers, two of which are opposite to the other three fingers, just like human thumb, so it can be held with other fingers, which makes koalas hold objects more safely and confidently. On the sole of the foot, all toes except the big toe have sharp claws, and the second toe is connected with the third toe.

When climbing near trees, koalas jump from the ground, grab the bark with their front paws, and then jump up and climb. So when a tree becomes koala's home tree and is often climbed, the scratches left by koala's claws on the bark are very obvious. Another sign that koalas use a tree is that there will be koala feces particles at the bottom of the tree.

Whether it is day or night, koalas will naturally assume different sitting and sleeping positions in the safe family tree, and at the same time, they will constantly move their positions on the tree because of avoiding the sun or enjoying the breeze. In hot weather, koalas spread their limbs and sway slightly to keep cool, while in cold weather, they huddle up to keep warm.

The koala comes down from the tree in a downward retreat. Koalas often descend to the ground and climb to another tree. At this time, they are often attacked by domestic dogs, foxes and Australian wild dogs, or killed and injured by passing cars. Koalas can swim, but only occasionally.

Koalas have thick fur, which helps them keep the temperature constant. And it can also be used as a raincoat when it rains to avoid being attacked by moisture and rain. The koala's fur presents a variety of colors, such as light gray to brown, with white patches on the chest, neck, limbs and inner ear. Adult male koalas have a particularly striking brown aromatic gland in the center of their white chest.

The koala's tail is particularly rich in hair. This is because koalas often use it as a cushion, and it is often polluted, so that when koalas fall to the ground with their buttocks facing you, it will be difficult to find it for a while.

Adult male koalas generally weigh between 8- 14 kg, and female koalas weigh between 6- 1 1 kg. Koalas distributed in the south are heavier and thicker because they need to adapt to the colder climate.

Koalas generally belong to Nocturnal Animals. They are active at night and dusk, because it can save more water and energy consumption than when the temperature is high during the day. Koalas spend an average of 18-22 hours a day sleeping and resting, leaving only 4 hours for eating, activities, personal hygiene and communication with other koalas. In the past, because koalas slept almost all day, people thought koalas were poisoned by eating eucalyptus leaves. Koalas, which are sleepy almost all day, are actually an effective low metabolism adaptation mechanism formed in their long-term evolution to adapt to low-nutrient foods and save energy consumption.

The most obvious feature of koalas is a developed nose, which makes koalas have a highly developed sense of smell, and can easily distinguish different kinds of eucalyptus leaves and find out which ones are edible and which ones are poisonous but inedible. Of course, you can also smell the warning smells left by other koalas.

Koalas make various sounds to communicate with other koalas. Male koalas mainly show their dominance and desire by roaring, so as to avoid consuming energy in the battle and show their position to other animals.

Female koalas don't roar as often as male koalas, but not necessarily. For example, when mating, females will make a quick cry, giving people the feeling that they are fighting each other. There will also be gentle ticking, whistling, gentle humming and snoring between mother koala and baby koala, and gentle snoring will express dissatisfaction with each other. But when koalas are afraid, they will make a sound similar to a baby crying, accompanied by trembling and shaking. Koalas also use the smell produced by their glands to mark trees.