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"Koalas are marsupials, not bears, even though people sometimes call them koala bears."
Koalas are sleepy tree-dwelling marsupials from Australia. They eat eucalyptus leaves, carry joeys in a pouch, and spend most of the day resting in branches.
Phascolarctos cinereusDiprotodontiaPhascolarctidae
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Habitat, diet, behavior, and more — everything on one page.
The koala (Phascolarctos cinereus) is an instantly recognizable symbol of Australia, beloved worldwide for its stout, tailless body, large fluffy ears, and spoon-shaped nose. Despite its widespread moniker "koala bear," this fascinating animal is not a bear at all, but rather a highly specialized arboreal marsupial. Endemic to the coastal regions of eastern and southern Australia, the koala has evolved an unique biology dedicated almost entirely to consuming the toxic and nutrient-poor leaves of eucalyptus trees. Its lethargic lifestyle, intricate digestive system, and unique reproductive strategies make it a fascinating example of evolutionary adaptation, though today it faces severe threats to its continued survival.
The koala represents a distinct branch of marsupial evolution. It is the sole extant representative of its family.
The order Diprotodontia is characterized by the presence of two large incisors on the lower jaw and syndactyly (fused second and third digits) on the hind feet, traits the koala shares with kangaroos, wombats, and possums. The koala's closest living relative is the wombat. The fossil record indicates that the koala's ancestors diverged and took to the trees during the Miocene epoch as Australia's climate shifted and vast tracts of rainforest were replaced by expansive Eucalyptus woodlands.
A koala's physical build is perfectly adapted to its rigorous arboreal lifestyle. They measure between 2 and 3 feet in length and exhibit varying weights depending on their geographic location; southern koalas can weigh up to 30 pounds, while their northern counterparts in Queensland are significantly smaller, averaging around 10 to 14 pounds.
Koalas are strictly endemic to Australia, inhabiting the states of Queensland, New South Wales, Victoria, and South Australia.
Their habitat is exclusively dictated by the presence of specific food trees. Thus, their primary biomes include:
Despite there being over 700 species of eucalyptus in Australia, koalas are incredibly fussy eaters, relying heavily on fewer than 50 species, and having strong regional preferences for just a handful of primary browse trees.
The koala is a folivore (leaf-eater) with one of the most specialized and challenging diets of any mammal. An adult koala consumes roughly 1 to 1.5 pounds of foliage daily.
Koalas are mostly solitary and highly territorial animals. Each individual maintains a distinct home range, the size of which is determined by the density and quality of the local food trees. While home ranges of males and females may overlap, koalas actively avoid physical contact outside of the breeding season.
Communication is primarily acoustic and olfactory. Males possess a large sternal scent gland on their chest, which they rub against tree trunks to mark their territory. During the breeding season, males produce a remarkably loud, deep, guttural bellowing sound to assert dominance and attract females. This vocalization is amplified by an extra pair of vocal folds situated outside the larynx.
As marsupials, koalas give birth to highly altricial young and utilize a pouch for early development.
(Population and conservation trend data sourced from the IUCN Red List of Threatened Species)
The koala's conservation status has deteriorated rapidly over the last two decades. The IUCN recently upgraded their status to Vulnerable, and the Australian government has declared populations in Queensland, New South Wales, and the Australian Capital Territory as Endangered. Their population trend is steeply decreasing.
The profound threats facing koalas include:
Koalas are marsupials, not bears, even though people sometimes call them koala bears.
A koala's diet is almost all eucalyptus leaves, which are tough and low in calories.
Koalas sleep up to 20 hours a day to save energy.
Joeys are born tiny and finish growing inside the mother's pouch.
A koala's big nose helps it sniff out the freshest eucalyptus leaves.
Each koala often prefers certain eucalyptus tree species in its home range.
Select a question to reveal the answer.
A koala is a tree-dwelling marsupial from Australia that eats eucalyptus leaves and raises its young in a pouch.
No. Koalas are marsupial mammals, not bears. People sometimes use the nickname koala bear, but they are not related to bears.
Wild koalas live in eucalyptus forests and woodlands along the eastern and southeastern coast of Australia.
Koalas are herbivores that eat mainly eucalyptus leaves. They rarely drink much water because leaves provide moisture.
A baby koala is called a joey. Joeys grow in the mother's pouch before riding on her back.
Eucalyptus leaves are hard to digest and low in energy, so koalas rest for many hours to save strength.
Koalas are listed as Vulnerable. Habitat loss, disease, dog attacks, and bushfires threaten wild populations.
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