Koalas eat only eucalyptus leaves. They consume about 1 to 2 pounds of leaves daily from 30 of the 600 eucalyptus species. Eucalyptus leaves are toxic and low in nutrition, requiring special digestive adaptations including a 6 to 8 foot long cecum.

No, koalas are not bears. They are marsupials, meaning they carry their young in pouches. The term koala bear is a misnomer. Koalas are more closely related to kangaroos and wombats than to any bear species.

Why are koalas endangered?

Koalas are vulnerable to extinction due to habitat loss from land clearing, dog attacks, vehicle strikes, disease, and climate change. Chlamydia infections affect up to 50% of koalas in some areas. Recent bushfires killed thousands and destroyed vast habitat areas.

Yes, koalas can swim and are actually quite competent swimmers. They will cross rivers and waterways to reach new eucalyptus trees, though they prefer to stay in the tree canopy. Swimming is not their primary means of movement but they can do it when necessary.

How big are baby koalas?

Newborn koalas called joeys weigh only 0.02 ounces and are less than an inch long at birth. They are born extremely underdeveloped after just 35 days of pregnancy and complete development in the mother's pouch for about 6 months.

Do koalas drink water?

Koalas get most of their water from eucalyptus leaves and rarely need to drink. However, during extreme heat or drought, koalas will come down from trees to drink from ground sources. The name koala comes from an Aboriginal word meaning no drink.

How long do koalas live?

Koalas typically live 10 to 12 years in the wild, though some individuals reach 15 to 18 years. Females generally live longer than males. In captivity with veterinary care and protection from threats, koalas can live over 20 years.

Koala Facts: Diet, Sleep Patterns, Behavior & Habitat

Australia's sleepy eucalyptus eating marsupials

Koalas are tree dwelling marsupials native to Australia that sleep up to 22 hours daily. They eat only eucalyptus leaves, one of the least nutritious diets.

Key Facts

Scientific Name

Phascolarctos cinereus

Weight

9 to 33 pounds

Height

24 to 33 inches

Sleep Duration

18 to 22 hours per day

Diet

Only eucalyptus leaves

Daily Food Intake

1 to 2 pounds of leaves

Eucalyptus Types

Eat 30 of 600 species

Lifespan

10 to 12 years in wild

Joey Pouch Time

6 months in pouch

Brain Size

Very small for body size

Social Behavior

Mostly solitary

Conservation Status

Vulnerable to extinction

Quick Stats

Attribute	Value
Daily Sleep	18 to 22 hours
Active Time	Only 2 to 6 hours awake
Leaf Consumption	1 to 2 pounds daily
Digestive System Length	Over 6 feet of intestine
Cecum Length	6 to 8 feet long
Joey Birth Weight	About 0.02 ounces
Gestation Period	Only 35 days
Brain to Body Ratio	Among smallest for mammals
Population Estimate	100,000 to 500,000 remaining

About Koala Facts: Diet, Sleep Patterns, Behavior & Habitat

Koalas sleep 18 to 22 hours per day, making them one of the sleepiest mammals on Earth. These tree dwelling marsupials survive on toxic eucalyptus leaves that would poison most other animals.

Why Koalas Eat Toxic Leaves That Kill Other Animals

Koalas eat exclusively eucalyptus leaves, one of the most difficult diets imaginable. Australia has over 600 eucalyptus species, but koalas eat only about 30 of them, showing strong preferences for specific types. An adult koala consumes 1 to 2 pounds of leaves daily. To digest this tough diet, koalas have the longest cecum relative to body size of any mammal, reaching 6 to 8 feet long.

How Sleeping 22 Hours Keeps Koalas Alive

Koalas sleep 18 to 22 hours per day because their eucalyptus diet provides minimal energy. Digesting toxic fibrous leaves requires significant effort and yields little nutritional reward. By sleeping most of the time, koalas conserve energy and reduce their metabolic needs. During their few waking hours, koalas spend most time eating or slowly moving between trees.

What Makes Joeys Eat Their Mother's Poop

Female koalas reach sexual maturity around 2 years old. Pregnancy lasts only about 35 days. Newborn joeys are tiny, weighing only 0.02 ounces and measuring less than an inch long. The joey remains in the pouch for about 6 months, feeding on milk and growing.

Why Male Koalas Bellow Half a Mile Away

Koalas are mostly solitary animals that maintain individual home ranges in eucalyptus forests. Males have larger territories that overlap with several female ranges. Male koalas produce loud bellowing calls during breeding season that can be heard over half a mile away. These deep resonant calls advertise the male's presence and attract females while warning rival males.

How Two Opposable Thumbs Grip Smooth Bark

Koalas are perfectly adapted for life in eucalyptus trees. They have sharp curved claws and rough pads on their hands and feet that provide excellent grip on smooth bark. Their hands have two opposable digits that work like thumbs, allowing them to grasp branches securely. Koalas have dense fur that repels water and provides insulation.

Why Chlamydia Threatens Half of All Koalas

Koalas are classified as vulnerable to extinction with populations estimated between 100,000 and 500,000. Major threats include habitat loss from land clearing for agriculture and urban development. Dog attacks kill many koalas when they descend from trees to move between forest patches. Chlamydia infections affect up to 50% of koalas in some areas, causing blindness, infertility, and death.

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Historical Analysis

⚡Historical Significance

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Koalas were hunted nearly to extinction in the early 1900s, with millions killed for their fur before hunting was banned.
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The name koala likely derives from the Dharug Aboriginal word gula meaning no water, referring to their minimal drinking needs.
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Europeans initially called koalas monkey bears or tree bears before recognizing them as unique marsupials.
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Koala populations crashed to as few as 1,000 individuals in the early 1900s before protection allowed recovery.
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The 2019 to 2020 Australian bushfires killed an estimated 5,000 koalas and destroyed 24% of their habitat in New South Wales.

📝Critical Reception

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Research revealed koalas have some of the smallest brains relative to body size of any mammal, possibly due to their low energy diet.
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Scientists discovered koala joeys must eat their mother's feces to acquire gut bacteria essential for digesting eucalyptus.
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Studies showed chlamydia infections affect up to 50% of koalas in some populations, causing blindness, infertility, and death.
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Research proved koalas can detect subtle differences in eucalyptus leaf chemistry, selecting only the least toxic leaves.
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Scientists found koalas have unique fingerprints nearly identical to human fingerprints, evolved independently for gripping branches.

🌍Cultural Impact

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Koalas became one of Australia's most beloved national symbols and major tourist attractions.
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The phrase smooth brained koala became internet slang for low intelligence, based on their unusually smooth brain surface.
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Koala rescue efforts during bushfires generated global attention and millions in donations.
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Holding koalas became a popular tourist activity, though many states now ban or restrict it for animal welfare.
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Koalas inspired countless stuffed toys, cartoons, and merchandise, becoming synonymous with Australian wildlife.

Before & After

📅Before

Before European settlement, koalas lived across eastern Australia in balance with their eucalyptus forest habitat. Aboriginal Australians hunted them sustainably for thousands of years without threatening populations.

🚀After

After Europeans arrived, koalas were hunted nearly to extinction for fur, then faced habitat destruction, disease, and bushfires. Chlamydia now infects up to half of some populations. The 2019 to 2020 fires killed thousands and burned vast habitat. Koalas are now endangered in parts of their range, with some scientists predicting extinction by 2050 without intervention.

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Did You Know?

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Koalas sleep 18 to 22 hours per day to conserve energy from their low nutrition diet

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They eat only eucalyptus leaves which are toxic to most other animals

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Koalas have a 6 to 8 foot long cecum to digest tough eucalyptus leaves

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Newborn joeys weigh only 0.02 ounces and are less than an inch long

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Mother koalas feed joeys pap containing bacteria essential for digesting eucalyptus

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Male koalas produce loud bellowing calls heard over half a mile away

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Why It Still Matters Today

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Koalas were listed as endangered in parts of Australia in 2022 as populations continue declining

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Climate change increases bushfire intensity and eucalyptus toxicity, compounding threats to koalas

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Chlamydia vaccines are being developed and tested to save infected koala populations

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Urban development continues destroying koala habitat faster than conservation efforts can protect it

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Scientists are using drones and detection dogs to survey remote koala populations more accurately

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Test Your Knowledge

How much do you know? Take this quick quiz to find out!

1. Why do koalas sleep up to 22 hours per day?

2. What unusual food must baby koalas eat to survive?

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Original Insights

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Koalas are not bears. Despite being called koala bears, they are marsupials more closely related to wombats than any bear.

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Koala brains are unusually smooth. Their brains have fewer folds than most mammals, possibly an adaptation to their low energy diet.

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Baby koalas eat poop to survive. Joeys must consume their mother's feces to acquire bacteria needed to digest eucalyptus.

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Koalas have fingerprints. Their prints are so similar to human fingerprints that they could theoretically contaminate crime scenes.

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Eucalyptus is toxic to most animals. Koalas evolved specialized livers and a 6 to 8 foot cecum to detoxify and digest these poisonous leaves.

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Male koala calls are shockingly deep. They produce bass bellows unexpected from their size due to a unique vocal organ.

Frequently Asked Questions

Koalas sleep 18 to 22 hours per day, making them one of the sleepiest mammals. They sleep so much because their eucalyptus diet provides very little energy. By resting most of the time, koalas conserve energy for digestion and basic survival.

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Sources & References

Koala Brain Size and Eucalyptus Diet Evolution

Koala Chlamydia Epidemic and Conservation

Koala Digestive System Adaptations

Koala Habitat Loss and Population Decline

Koala Pap Feeding and Gut Microbiome Transfer

This article is reviewed by the Pagefacts team.

Editorial Approach:

This article explains why koalas sleep 22 hours due to their toxic, nutritionless diet, reveals the surprising necessity of joeys eating their mother's feces to survive, and confronts the chlamydia epidemic threatening their survival.