Koala (Phascolarctos cinereus)

MammalMarsupialFolivore

Overview

The koala (Phascolarctos cinereus) is an arboreal marsupial endemic to Australia. Despite the common nickname "koala bear", koalas are not bears at all — they are marsupials, more closely related to wombats than to any bear. Koalas are notable for a highly specialised diet consisting almost entirely of eucalyptus leaves and for a low-energy lifestyle marked by long periods of rest in trees.

Habitat & Range

Koalas inhabit eucalypt forests, woodlands, and coastal mallee habitats across parts of eastern and southeastern Australia. Habitat distribution depends on the presence of specific preferred eucalyptus species, which varies regionally. Some local populations have been the subject of significant range contraction over recent decades.

Diet

Koalas are eucalyptus-leaf specialists. Their digestive system is adapted to process the relatively low-nutrient, toxic-compound-rich leaves of various Eucalyptus species. Koalas typically eat large daily amounts of leaves and obtain most of their water from the leaves themselves, though they will also drink free water when necessary, particularly during drought.

Behavior

Koalas are almost entirely arboreal, descending to the ground primarily to move between trees. They spend a very large fraction of each day resting and feeding. Adult koalas are largely solitary and maintain overlapping home ranges. Mothers carry their developing joey in the pouch and then on the back after the joey is too large for the pouch.

Human Interaction & Conservation

Koala populations face significant pressures from habitat loss and fragmentation, vehicle strikes, dog attacks, chlamydial and other disease outbreaks, and large-scale fires — including the 2019–2020 Australian bushfires, which had severe impacts on populations in eastern Australia. Some populations are now listed under stronger protective categories than they were previously. Verify current status at iucnredlist.org and Australian conservation sources before publication.

Similar Animals

The koala's closest living relatives are wombats, also marsupials. Together they form the order Diprotodontia, which also includes kangaroos, possums, and a number of other Australian and surrounding-region species.

Frequently Asked Questions — Koala

Are koalas bears?

No. Koalas are marsupials, not bears. The traditional nickname 'koala bear' is misleading. Their closest living relatives are wombats; they are not part of the family Ursidae.

Why do koalas sleep so much?

Koalas have a low-energy lifestyle driven by their diet. Eucalyptus leaves are tough, low in available nutrients, and contain compounds that the koala must detoxify. Long rest periods help reduce energy demand and support digestion.

Are koalas endangered?

Conservation status varies by population. Several Australian state and federal listings now classify some koala populations under stronger protective categories than previously, reflecting bushfire impacts, habitat loss, and disease. Always verify current designations on the IUCN Red List and Australian conservation sources before quoting.

Can koalas eat anything other than eucalyptus?

Koalas are eucalyptus specialists. They may occasionally consume small amounts of leaves from a few other plant species, but their digestive physiology is built around eucalyptus and they cannot survive on most other foliage.