Koalas are iconic marsupials, instantly recognizable by their fluffy ears, large noses, and sleepy demeanor. These unique marsupials are native to Australia and rely on specific environments. Their survival hinges on the health and availability of these habitats, making their geographic distribution central to their existence. Koalas are not bears, despite their common nickname, and are distinct among marsupials, classified into their own family, Phascolarctidae.
Where Koalas Live
Koalas are found across eastern and southeastern Australia, in Queensland, New South Wales, Victoria, and parts of South Australia. Their range extends from northern Queensland to islands off Victoria and South Australia. Historically, koalas also inhabited parts of Western Australia and the Northern Territory, though no fossil records suggest their presence in Tasmania.
The populations within this broad range are often fragmented, meaning they are separated into smaller, isolated groups. While their overall distribution has not drastically reduced over the past two centuries, individual populations have declined significantly in many areas. For instance, koalas in South Australia were largely hunted to extinction but have since been repopulated through relocation efforts from Victorian stock.
Essential Habitat Needs
The presence of specific eucalyptus species defines suitable koala habitat, as these trees provide both their primary food source and shelter. Koalas are folivores, consuming up to 1.3 kilograms of eucalyptus leaves daily, which also supply them with water. While they can use many tree species, individual koalas at a single site typically rely on only a few preferred species for most of their nutrition.
Beyond specific food trees, koala habitat requires sufficient annual rainfall. They also thrive where prolonged high temperatures do not cause heat stress and mortality. Koalas prefer open forest and woodland communities. Connected tree corridors are also important, allowing koalas to move safely between habitat patches, as they typically travel on the ground between trees.
Threats to Koala Habitat
The primary threat to koalas is habitat loss and fragmentation, largely driven by human activities such as land clearing for agriculture, urban development, mining, and infrastructure. Since European settlement, over 80% of original koala habitat has been destroyed. This destruction forces koalas into close proximity with human settlements, increasing their exposure to hazards.
Climate change further exacerbates these challenges, leading to increased droughts and bushfires. Prolonged high temperatures cause heat stress, and a shrinking climatically suitable area forces koalas to move more frequently in search of water or new habitats. This increased movement also makes them more vulnerable to secondary threats like road accidents and dog attacks. Additionally, diseases such as Chlamydia and koala retrovirus (KoRV) pose significant threats, with Chlamydia causing blindness, infertility, and death in affected populations, particularly when koalas are stressed from habitat degradation.
Protecting Koala Habitats
Strategies are underway to conserve and manage koala habitats across Australia. Habitat restoration and reforestation initiatives are planting native trees, including preferred koala food sources, in fragmented areas. These efforts often involve partnerships between government bodies, landholders, and conservation organizations to restore degraded areas and establish new koala habitat.
Creating wildlife corridors aims to reconnect isolated habitat patches, allowing koalas safe passage for foraging and breeding. These corridors can be continuous strips of native vegetation or strategically planted “stepping stones” of trees. Land-use planning regulations are also being implemented to prohibit clearing koala habitat within designated priority zones. Research efforts are ongoing to better understand and manage diseases like Chlamydia and KoRV, as well as to develop strategies for koala adaptation to climate change impacts.