Koalas are tree-living Australian marsupials, not bears. They live in eucalyptus forests in eastern and south-eastern Australia and eat almost nothing but eucalyptus leaves. They sleep 18 to 22 hours a day to save energy. A newborn joey weighs under a gram and grows in its mother’s pouch for about six months.
koalas quick facts
- Koalas are marsupials, and their closest living relative is the wombat.
- Koalas sleep 18 to 22 hours a day.
- Koalas prefer only about three dozen of the more than 600 kinds of eucalyptus.
- A newborn koala weighs only about 0.4 to 1 gram.
- Koalas in Queensland, New South Wales and the ACT were listed as Endangered in 2022.
What is a koala?
A koala is a furry, tree-living animal from Australia. With its round face and fluffy ears, it is one of the best-known animals in the world.
Many people call it a koala bear, but a koala is not a bear at all. It is a marsupial, like a kangaroo. That means its babies are born tiny and grow up in their mother’s pouch.
Koalas belong to their own family, called the Phascolarctidae. The koala is the only living member of it. Its closest living relative is the wombat.
What koalas look like
A koala is about 68 to 82 cm long, about the size of a big teddy bear. It has thick, ash-grey fur, a white chest, a round head, fluffy ears and a large, dark nose.
Its fur is thick and woolly, which keeps it warm and helps rain run off when it sits in a tree during a storm.
Koalas have strong, sharp claws for gripping bark. Their front paws have two thumbs set apart from the other three fingers, which helps them hold on tightly to branches. Their fingerprints even look a lot like ours.
Where koalas live
Wild koalas live only in eastern and south-eastern Australia. Their range is patchy, stretching from northern Queensland down to southern Victoria and south-eastern South Australia.
They live in eucalyptus forests and woodlands. Eucalyptus trees, also called gum trees, are their homes, their beds and their food.
Koalas spend most of their time up in the trees, sleeping and feeding. Now and then they climb down and walk along the ground to find a new tree.
A diet of eucalyptus leaves
Koalas eat almost nothing but eucalyptus leaves, along with a few flowers and stems. Few other animals can live on them, because the leaves are tough, low in goodness and full of chemicals that would poison most animals.
There are more than 600 kinds of eucalyptus, but koalas are fussy. They prefer the leaves of only about three dozen kinds.
At San Diego Zoo, each koala eats about 1 to 1.5 pounds (454 to 680 grams) of leaves a day.
To help them digest this tough food, koalas have a very long part of the gut called the caecum. Tiny living things inside it help break the leaves down. Koalas sometimes eat a little soil as well, which also seems to help.
The leaves are full of water, so koalas get most of the moisture they need from their food and rarely need to drink.
Sleepy koalas
Koalas are famous for sleeping. They sleep for 18 to 22 hours a day.
That is not because they are lazy, or because eucalyptus makes them drowsy. It is because their food gives them very little energy, so they save as much as they can by resting.
They usually sleep wedged into the fork of a tree, where two branches meet, so they do not fall out.
A koala’s day
Koalas are most active at night and around dusk, when it is cooler. That is when they climb about their trees and do most of their eating.
During the day, they usually sleep, curled up in the fork of a branch. A koala might move to a different tree only a few times a day, or even less.
Each koala has its own home range, an area of forest with the trees it likes to use. Koalas mostly live alone, but their home ranges can overlap with their neighbours’.
Keeping cool and keeping in touch
Australian summers can be very hot. To cool down, koalas sometimes hug the trunks of trees, whose wood can be cooler than the air. On the hottest days, they may also climb down to drink.
Male koalas have a scent gland in the middle of their chest. They rub it against tree trunks to leave their smell, a message to other koalas that says “this is my patch”.
Koala sounds
Koalas can be surprisingly noisy. Male koalas make a loud, deep bellow, especially in the breeding season.
San Diego Zoo Wildlife Alliance describes it as sounding like a mixture of a motorcycle revving and a pig snorting. It can be heard a long way through the forest.
Baby koalas
Koalas breed in summer, and a female usually has one baby a year. A baby koala is called a joey.
A newborn joey is tiny, weighing only about 0.4 to 1 gram, less than a paper clip. It is hairless, blind and has no ears showing. It crawls into its mother’s pouch, where it drinks her milk and keeps growing.
A koala’s pouch opens towards its back legs, not upwards like a kangaroo’s. Strong muscles keep it closed so the joey does not fall out.
The joey stays in the pouch for about six months. Then it starts to eat a special soft food called pap, which its mother makes in her gut. Pap helps the joey get used to eating eucalyptus and gives it the tiny living things it needs to digest the leaves.
After that, the young koala rides around on its mother’s back until it is ready to live on its own.
How long do koalas live?
Koalas usually live for about 10 to 15 years in the wild and in zoos.
Male koalas tend to have shorter lives than females, partly because they travel further and face more dangers.
Why koalas are so fussy
Eucalyptus leaves are not an easy meal. They are hard to chew, and they contain oils and chemicals that would make most animals ill.
Koalas can cope with these chemicals, but even they are choosy. They sniff leaves carefully before eating them, picking the ones with the most goodness and the fewest harmful chemicals.
Because they depend on just a few kinds of tree, koalas cannot simply move to another forest when theirs is cut down. That is one reason losing their habitat is so serious for them.
Why koalas are in danger
Koalas are in trouble. On 12 February 2022, koalas in Queensland, New South Wales and the Australian Capital Territory were listed as Endangered under Australia’s national environment law.
The biggest threat is the loss of their eucalyptus forests, as land is cleared for farms, houses and roads. Near big cities such as Sydney, koala numbers have fallen as their habitat has disappeared.
Koalas also face bushfires, drought, a disease called chlamydia, attacks by dogs and being hit by cars when they cross roads.
People are working hard to help them. They are planting new eucalyptus trees, designing towns and roads that are safer for koalas, and using vaccines to protect koalas from chlamydia.
Meet some of the koala’s Australian neighbours in our guide to animals in Australia.
How you can help koalas
If you live in or visit koala country, there are ways to help.
Drive slowly in areas where koalas live, especially at dusk and at night, when they are most likely to be crossing roads.
Keep dogs inside or in a secure yard at night, so they cannot attack koalas that come down from the trees.
You can also support groups that plant new eucalyptus trees and care for injured koalas. Even learning about koalas and telling others helps, because people protect what they care about.
Three things people get wrong
Koalas are not bears. They are marsupials, whose babies grow up in a pouch.
Koalas do not sleep because eucalyptus makes them drowsy. They sleep 18 to 22 hours a day to save energy, because their food gives them so little.
Koalas do not live all over Australia. Wild koalas live only in the east and south-east, where eucalyptus forests grow.
Did you know? A koala’s pouch opens towards its back legs, and strong muscles keep it closed so the joey cannot fall out.
Try it
Count how many hours you sleep in a night. Now imagine sleeping 20 hours a day, like a koala. How much time would be left for eating and everything else?
Knowledge check
Why do koalas sleep so much?
Show answer
Because eucalyptus leaves give them very little energy, so they rest to save it.
What is pap?
Show answer
A soft food made in the mother koala’s gut that helps her joey start eating eucalyptus leaves.
Frequently asked questions
Are koalas bears?
No. Koalas are not bears. They are marsupials, like kangaroos, and their babies grow up in a pouch. Their closest living relative is the wombat.
What do koalas eat?
Koalas eat almost only eucalyptus leaves, plus a few flowers and stems. They prefer about three dozen of the more than 600 kinds of eucalyptus.
Why do koalas sleep so much?
Koalas sleep 18 to 22 hours a day to save energy. Eucalyptus leaves are tough and low in nutrients, so their diet gives them very little energy.
How big is a baby koala?
A newborn koala joey weighs only about 0.4 to 1 gram. It crawls into its mother’s pouch and stays there for about six months.
Where do koalas live?
Wild koalas live in eucalyptus forests and woodlands in eastern and south-eastern Australia, from northern Queensland to southern Victoria and south-eastern South Australia.
Are koalas endangered?
Yes. Koalas in Queensland, New South Wales and the Australian Capital Territory were listed as Endangered in 2022, mainly because of habitat loss, bushfires, disease and cars.
Sources
- Australian Museum: koala — size, fur, range, diet and digestion, joeys and pap, behaviour and status
- San Diego Zoo Wildlife Alliance: koala — sleep, diet, eating soil, birth weight, pouch, bellow and lifespan
- Australian Government, DCCEEW: koala listing under national environmental law — the 2022 Endangered listing and work on fire, habitat, urban design and chlamydia
