Koala Koala Bear

The koala is a cuddly, nocturnal, tree-dwelling Australian herbivore with grey fur, a big black nose, and large fluffy ears.

Because it looks like a teddy bear, many people refer to this animal as a Koala Bear. This is not correct. The koala is not a bear at all. It is a plant-eating marsupial mammal found only in Australia. Real bears are omnivorous–they eat almost anything and are placental mammals.

The koala spends almost all of its life in trees, only coming down to the ground to travel from one tree to another. It is a fairly harmless animal. However, if provoked, it can scratch and bite. Its closest relatives are other marsupials such as the kangaroo and wombat. Koala is pronounced "co-aa-laa".

A male koala is called a boomer
A female koala is called a doe
A baby koala is called a joey

Koala - Description & Characteristics What Do Koalas Look Like?

Koalas vary in size and fur colour depending on where they live in Australia. Those found in the warmer climates of Queensland and northern New South Wales are lighter in colour and significantly smaller than those found furthest to the south in Victoria, where it is much colder.

Their fur is grey to brown in colour. They have large oval-shaped furry ears, small forward-facing eyes, big noses, and no tails. The fur on their chests is usually white or yellowish-grey. Male koalas also have a moist, dark, hairless patch on the middle of their chests with a scent producing gland. They rub the scent from this gland on tree trunks to mark their territories.

Photo: Koala climbing a tree

Depending on where it lives, an adult male koala can weigh between 5-12 kilos. The female koala is about 50% smaller than the male. The male animal also has a more curved nose than the female.

The koala's posterior (bottom) has cartilaginous padding that acts like a cushion on which the animal sits while it wedges itself between the fork of tree branches while resting or sleeping.

It has long arms and legs with very sharp claws, which it uses to cling onto trees and branches. Just like human fingerprints are unique, each koala's fingerprint is unique and different from that of every other koala. Koalas don't have a tail.

The koala has a very small brain. It occupies only 40% of its cranial cavity and makes up only 0.2% of its body weight (compared to a human’s 1.6%). Scientists believe that the kola’s brain has actually shrunk over evolutionary time as a result of its low energy diet and very safe and sedentary lifestyle.

In keeping with its energy conservation lifestyle, the koala moves slowly, feeds mainly at night, and sleeps between 18 to 22 hours each day. When on the ground, it has a slow, awkward walk but can gallop for the safety of the nearest tree if frightened.

10 Interesting Koala Facts

  1. The koala has a padded bottom because it sits on it so much. Because of this, it doesn't have a tail.
  2. They have unique finger prints, like humans.
  3. Koalas sleep 18-20 hours a day.
  4. To conserve energy, a koala moves slowly and feeds mainly at night.
  5. The koala's brain has shrunk over evolutionary time.
  6. The koala prefers to live by itself.
  7. Koalas eat only 35 out of over 600 types of eucalyptus.
  8. This is because most types of eucalyptus leaves are highly toxic.
  9. Koalas were almost hunted to extinction.
  10. A US president helped save the koala.

Koala - Habitat & Distribution Where Do Koalas Live?

Photo: Koala distribution and habitat map

Koala Eviction Fight Video

Photo: Young koala evicted from a tree

Koalas are only found in Australia. Their natural habitats are temperate, tropical and sub-tropical wooded areas with eucalyptus trees along the eastern seaboard of mainland Australia starting in the north around Townsville in Queensland and along the coastal fringe to south-eastern South Australia. Humans have also introduced them to areas around Adelaide in South Australia and some coastal islands such as Kangaroo and French islands. They don't live in desert or rainforest areas. The quality of the trees in a given area determines how many koalas can effectively live in that area. This is called the carrying capacity of the forest.

The Koala is a solitary animal that prefers to live by itself. It marks out a territory consisting of several trees, called a home range, and rarely ventures out of it. Within this home range, it will identify and mark its favourite feeding trees referred to as its home trees and defend it aggressively. The size of a koala's home range varies according to the density and nutritional quality of the trees of the area. In Queensland, for example, where the vegetation is less nutritious, a koala's range could be as large as 135 hectares. In Victoria, on the other hand, where the vegetation is lusher, it could be as little as 1 hectare.

A koala will mark its home trees and defend them fiercely. While home ranges may overlap, a koala will not venture onto the home trees of another koala (see video).

Koala - Diet What do Koalas Eat?

Photo: Koala feeding on eucalypts leaves

The koala is a folivore. That is, it is a plant-eating animal that specialises in eating leaves. Its diet is primarily the leaves of eucalyptus trees. These leaves are highly poisonous, hard to digest, and very low in nutrition. The koala’s ability to eat these leaves gives it access to a widely available food source in the Australian environment that other mammals cannot eat. The koala will also eat the leaves of other trees such as Acacia and Melaleuca. The koala usually gets all the moisture it needs from its food and rarely drinks water. As a result, it produces very dry faecal (poo) pellets.

There is a common myth that koalas are fussy eaters. It is true that koalas eat only 35 out of over 600 types of eucalyptus. This is due more to the toxicity of the plant than the koala's fussiness. The best way to define the koala's eating habits is to say that it is a "selective eater". The koala uses its highly sensitive nose to pick out only those leaves that are high in nitrogen and low in tannins and essential oils. In this way, the koala protects itself from being poisoned by its food.

The Eucalypts Trees Defences

Eucalyptus trees have adopted several defensive mechanisms to make themselves less palatable (edible) to herbivores. Their leaves contain tannins, phenols, cyanogenic glycosides and essential oils that are toxic to most animals. The leaves are also high in phenols and terpenes which reduce the ability of micro-organisms in the intestine to digest leaves.

The adult koala is a nocturnal feeder (that is, it eats mostly at night). It eats about 400 grams (14oz) of leaves a day. It nips the leaves with its front incisor teeth and chops them with its sharp molar teeth before swallowing. It also has cheek-pouches for storing extra leaves prior to chewing. The koala requires very little water and usually gets all the liquid it needs from the leaves it eats. If necessary, it will supplement this with water from tree hollows and on the ground.

The Koala's digestive system is specially adapted to detoxify the poisonous chemicals in its food and to extract as many nutrients as possible. It has a small stomach but a very large cecum, which is nearly 1.3 meters long and supports 45 different species of bacteria, some of which are excellent at neutralising toxins. It retains its food in its intestine for up to 22 hours to give its digestive system time to break down and absorb as much nutrient as possible.

If you want even more information, here is an excellent scientific paper on the koala's diet.

Koala - Reproduction & Life Cycle How a Baby Koala is Born

Photo: Koala mother with joey on its back

Photo: Newborn joey finding its way to pouch

The Koala is a solitary animal that prefers to live by itself. It is only social during the breeding season, between September and March, when it actively seeks out brief encounters with other kolas. At this time, there is much bellowing and agitation all around. It is also at about this time that last year's joeys are weaned away from their mothers and sent off to establish their own home range.

Being a marsupial animal, the actual pregnancy is very short, lasting just 33-35 days. The female gives birth to a single baby koala, called a 'joey'.

This joey is born while at a very early embryonic stage of development. It weighs a mere 0.5gms (0.02oz) and looks like a pinkish jelly bean with tiny stumpy limbs. It is about the size of a human thumbnail. About 2 cm (0.05 in) in length.

At this stage, the baby joey is hairless, blind, and has no ears; but has a well-developed sense of smell, forelimbs (arms), and lips. This minuscule living embryo is at the most vulnerable stage of its life. Having exited the mother's birth-canal, using its well-developed sense of smell, the tiny joey uses its strong forelimbs to heave itself up its mother's abdomen and into the safety of her pouch. Once inside the mother's pouch, it attaches itself to a nipple inside the pouch, and there it develops into a viable koala.

Unlike a kangaroo's pouch which has its opening at the top, the koala's pouch is located in the centre of its abdomen and has an opening that faces forward. This adaptation is more suitable for a climbing animal such as the koala. As an added safety, in order to prevent the little joey from falling out if its pouch, the koala uses a strong sphincter muscle to keep the entrance of the pouch closed, so its baby doesn't accidentally fall out.

Koala & Baby Video

Photo: Koala mother and joey walking

The Koala's Pouch Muscles

The koala has an upward facing pouch so is joey doesn't fall out as it moves about. The sphincter muscle at the entrance of a koala mother's pouch works a bit like a drawstring on a bag. By tightening the sphincter muscle, the koala can control how big the opening of its pouch is.

As the joey approaches six months, it is finally ready to see the world and starts to peak out of its mother's pouch. While still on drinking milk, the joey also starts to feed on "pap" a special runny jelly-like substance produced by its mother. This substance is sometimes confused as being the mother's faeces or poo. This is not correct. It a substance produced in the mother's caecum and passed out through the mother's rectum. Pap has a vital function in the joey's transition from weaning to leaf-eating. Through the pap the mother passes essential gut flora micro-organisms that the joey will need to be able to digest eucalyptus leaves. From about this time the little joey starts to pop its head out of the pouch to nip on eucalyptus leaves as its mother climbs about the trees.

It soon starts clinging onto the mother's underbelly and then when this becomes too difficult it starts to ride on its mother's back feeding on leaves as it travels with its mother. It still returns to its mother's pouch for safety and a drink of milk until it finally becomes too big to fit into the pouch. By about the twelfth month, when the mother is ready to breed again, the young joey is weaned from its mother and sets out on its own.

A male koala reaches sexual maturity at about four years and the female in about three years. The male has a lifespan of about 10 years. The female koala lives to 15 about years.

The Koala's Near Extinction Experience Humans Slaughtered Koalas

Photo: Hunter shooting koalas from trees

When European settlers first arrived, there was a large koala population in Australia. The native Aborigines, who hunted them for food, had been kept in check.

With European settlement starting in 1778, the Aboriginal populations declined drastically, and the koala no longer had its natural predator (the aborigine hunter), and the population began to grow significantly because the Europeans didn't seem to like eating koala meat.  Only small-scale hunting of these animals, by the new settlers, took place for their pelts.  

US President Herbert Hoover Helped Save the Koala

US President Herbert Hoover, while he was Secretary for Commerce in 1927, banned the importation of koala and wombat skins into the US. This ban is still in place. Hoover as a young man had worked in the gold-fields of Western Australia and was well aware of the little koala and its brutal fate in the hands of Koala Hunters.

By the mid-nineteenth century, as the European settlements grew significantly, a lucrative trade in koala skins sprung up.  Koala hunters shot, poisoned or snared these animals off their tree perches and bludgeoned them to death and sold their skins for export. The main export markets were the US, Canada and Europe where the koala's soft waterproof fur was used to make hats, gloves and fur linings for coats.

Photo: Koala pelts in back of a truck

The number of koalas kills was staggering. In 1902 in the state of New South Wales alone 600,000 koala skins were sold publicly. The historian Ellis Troughton has claimed that nearly 2 million koala skins were exported from Australia in 1924. By the late 1920s, the koala was almost extinct. The situation was so dire that they became extinct in the state of South Australia. There were only a few hundred left in New South Wales and a few thousand in Victoria and Queensland.

The wide-scale indiscriminate slaughter of these animals finally led to huge public outcry.  In 1927 Koala hunting was banned throughout Australia.  By this time the koala was nearly extinct, but it finally got a much-needed reprieve. The koala population, however, has never recovered its earlier numbers.

Koala - Conservation Status How Many Koalas are Left?

Photo:Koala is becoming extinct

The koala was hunted to near extinction in the early 20th century. Acknowledging that the number of koalas was still in serious decline, in 2012, the government of Australia declared that the koala was vulnerable throughout Australia. There is no definite estimate of the number of koalas still in the wild. The number range from 100,000 to 500,000 animals. The IUCN Threatened Species List uses a figure of about 300,000.

Koala Threats and Predators What Kills Koalas

Habitat Loss

Photo: Heavy machinery destroying a koala's habitat

As with most other native Australian animals the koala suffers from the destruction, fragmentation, and loss of its habitat. The koala feeds on only certain types of eucalyptus trees. It is estimated that nearly 80% of Koala habitat has already disappeared. Almost all of this de-forestation has been the result of human activity such as logging, farming, and suburban sprawl.
(Photo: See a frightened koala being callously dislodged from a tree).

Motor Vehicles & Dog Attacks

Photo: Koala caught in the grill of a car

Motor vehicle strikes and dog attacks account for as many as 4,000 koala fatalities each year. While safe in their trees, koalas, are vulnerable when they are on the ground walking from one feeding tree to another.
(Photo: This lucky koala had an 80kph impact with a car and survived unscathed).

Bush Fires

Photo: A thirsty kola accepting a drink from a fire-fighter

Forest fires in Australia are fast and burn intensely. The koala is too slow to run away from these fires and usually seeks shelter by climbing to the top of a tree. Sam the Koala captivated the hearts of millions of people when she was rescued by a fire-fighter after the Black Saturday brushfires in 2009.


Photo: Sick koala being fed

Diseases associated with the chlamydia organism are the most serious threat to the koala population. Chlamydia can cause blindness, urinary and reproductive tract infections (which leads to infertility) and pneumonia.

What is a Group of Koalas Called?

There is no collective noun for a group of koalas (such as, for example, a herd of cattle). This is because koalas are solitary animals and don't live in groups. Some names in common usage are "koala colonies' or koala populations". A very creative person suggested that maybe we should call them a "cling" of koalas.

How did the Koala get its Name? Where does the word 'Koala' come from?

Photo: Koala mother and joey on a branch

The name koala is derived from the word gula from the Dharug language of the Yuin-Kuric aboriginal people, who once lived around the areas that are now the cities of Sydney and Canberra.

The true meaning of the word is now lost. It is sometimes asserted that the word gula meant "no drink". As far as the Dharug language is concerned this is not correct. Many other aboriginal tribes also had names for this animal such as koolawong, colah, karbor, colo, coolbun, boorabee, burroor, bangaroo, pucawan, banjorah, and burrenbong. Some of these words meant "no drink".