Koalas are nocturnal marsupials famous for spending most of their lives asleep in trees. This sedentary lifestyle can be attributed to the fact they have unusually small brains and survive on a diet of nutrient-poor leaves. The koala's leaf of choice is eucalyptus, a particularly fibrous and highly toxic plant. Luckily for koalas, what they lack in brain power they make up for in the length of their intestine, which measures a colossal two metres and is packed with super micro-organisms that detoxify the leaves.
Scientific name: Phascolarctos cinereus
Orphaned koala babies get a trip to the vet.
Orphaned koala babies get a trip to the vet.
Young koalas stay dependent on their mothers for a whole year.
Though not classified as endangered, Australia’s iconic marsupials were placed on the IUCN's Climate Change Hit List following the Copenhagen summit in 2009. Since the European settlement of Australia, koalas have fared badly. In the past two centuries, vast numbers were killed for their fur, but today, it is habitat loss and the impact of urbanisation that are the leading threats. But more than anything, it's their fussiness over food that led the IUCN to nominate them for the climate change hit list. Rising carbon dioxide levels in the atmosphere saps the nutrients and causes toxicity levels to rise in the koala's preferred diet of eucalyptus leaves. If eucalyptus becomes unpalatable to koalas, malnutrition and potential starvation will follow.
Species range provided by WWF's Wildfinder.
The following habitats are found across the Koala distribution range. Find out more about these environments, what it takes to live there and what else inhabits them.
Discover what these behaviours are and how different plants and animals use them.
Additional data source: Animal Diversity Web
Population trend: Unknown
Year assessed: 2008
Classified by: IUCN 3.1
The koala (Phascolarctos cinereus or inaccurately, koala bear[a]) is an arboreal herbivorous marsupial native to Australia. It is the only extant representative of the family Phascolarctidae, and its closest living relatives are the wombats. The koala is found in coastal areas of the mainland's eastern and southern regions, inhabiting Queensland, New South Wales, Victoria and South Australia. It is easily recognisable by its stout, tailless body; round, fluffy ears; and large, spoon-shaped nose. The koala has a body length of 60–85 cm (24–33 in) and weighs 4–15 kg (9–33 lb). Pelage colour ranges from silver grey to chocolate brown. Koalas from the northern populations are typically smaller and lighter in colour than their counterparts further south. It is possible that these populations are separate subspecies, but this is disputed.
Koalas typically inhabit open eucalypt woodlands, and the leaves of these trees make up most of their diet. Because this eucalypt diet has limited nutritional and caloric content, koalas are largely sedentary and sleep for up to 20 hours a day. They are asocial animals, and bonding only exists between mothers and dependent offspring. Adult males communicate with loud bellows that intimidate rivals and attract mates. Males mark their presence with secretions from scent glands located on their chests. Being marsupials, koalas give birth to underdeveloped young that crawl into their mothers' pouches, where they stay for the first six to seven months of their life. These young koalas are known as joeys, and are fully weaned at around a year. Koalas have few natural predators and parasites but are threatened by various pathogens, like Chlamydiaceae bacteria and the koala retrovirus, as well as bushfires and droughts.
Koalas were hunted by indigenous Australians and depicted in myths and cave art for millennia. The first recorded encounter between a European and a koala was in 1798, and an image of the animal was published in 1810 by naturalist George Perry. Botanist Robert Brown wrote the first detailed scientific description of the koala in 1814, although his work remained unpublished for 180 years. Popular artist John Gould illustrated and described the koala, introducing the species to the general British public. Further details about the animal's biology were revealed in the 19th century by several English scientists. Because of its distinctive appearance, the koala is recognised worldwide as a symbol of Australia. Koalas are listed as of Least Concern by the International Union for Conservation of Nature. The Australian government lists populations in Queensland and New South Wales as Vulnerable. The animal was hunted heavily in the early 20th century for its fur, and large-scale cullings in Queensland resulted in a public outcry that initiated a movement to protect the species. Sanctuaries were established, and translocation efforts moved koalas whose habitat had become fragmented or reduced to new regions. The biggest threat to their existence is habitat destruction due to agriculture and urbanisation.
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