If you go for a walk in one of the ancient Australian eucalyptus forests, you probably won’t notice koalas perched high in the treetops. Its bottom, a vortex of white, gray and brown fur, blends in with the colorful bark and creates camouflage that is hard to overcome.
But the koala knows you’re there. He watches you quietly, half, like a flight-delayed passenger watching a boring movie in flight. Koalas have sharp incisors and long claws and can be wild when provoked, but they usually don’t mind what’s going on around them, says Rebecca Johnson, deputy director of science and chief scientist at the Smithsonian’s National Museum of Natural History. Their lack of interest is not personal. It is a natural reaction to their main source of food and water: eucalyptus leaves.
Eucalyptus is a toxic plant. Koalas have specialized digestive systems that allow them to eat certain varieties of the poisonous tree, but it requires a lot of effort. All the energy expended on eating and digesting nutrient-poor leaves makes these unobtrusive tree dwellers incredibly sleepy.
Every animal plays an important role in a balanced ecosystem. Koalas are no exception, even if you are forgiven for thinking otherwise, says Jennifer Tobey, a researcher at the San Diego Zoo Wildlife Alliance. “He sleeps most of the time. How complex can these little boys be? I’ll tell you, we’re still learning new and different things about them.”
Koalas are threatened with extinction in New South Wales in less than 30 years. Similar projections are likely to follow in other parts of the continent. Australia is a country of extremes, facing rising temperatures and the growing frequency and severity of forest fires and droughts that are rapidly killing eucalyptus and koala habitats.
The devastating fires in Australia in 2019 and 2020 killed 61,000 koalas and burned more than 28 million acres. These fires were not typical, but are part of a growing trend that could become Australia’s new standard.
Other threats, such as deforestation, predators, diseases and road accidents, have already complicated the situation of the koalas and their natural environment and reduced the population. In the last 20 years alone, the number of koalas has halved, forcing the Australian government to change the protection status of koalas from endangered to endangered in most countries in February.
No one knows exactly what would happen if the Australian iconic marsupial became extinct, but they all agree on one thing: they never want to find out. “Unfortunately, we tend to find out too late, you know, when such an animal disappears,” says Tobey.
A look into the past
The first koalas date back 20 million years, says Johnson. During this time, there were up to 20 species of koalas in various locations throughout Australia. Phascolarctos cinereus, the only species of koala that remains today is only 350,000 years old.
Most of the estimated 32,065 to 57,920 Australian koalas live on the east and southeast coasts as their habitats push more and more toward the sea. Johnson refers to their remaining territory as a “piece” of the coast.
“Koalas have a long history of exploitation, especially by the earliest European settlers in Australia, so they have gone through many population threats through hunting or land clearing and habitat modification,” says Johnson. Practices such as deforestation, along with predators, disease and climate change, are a growing threat to koalas.
This was not always the case. Indigenous people who have lived in Australia for at least 50,000 years have coexisted peacefully with koalas for generations, says Johnson. The word “koala” comes from the Dharugian word “gula”, which means “no water”, which refers to the way marsupials depend on eucalyptus do not drink water.
Many Indigenous cultures in Australia even incorporate koalas into their stories of creation and belief systems, Johnson adds, which include a close bond with nature and respect for living things. “It’s just a recognition that this kind of traditional knowledge has obviously been known for a very long time, and it’s really important that we re-set the way we can think about it.” [caring for koalas] future.”
What would we lose
If koalas become extinct, what would happen? Short answer: Nobody really knows, but scientists have some educated estimates.
Tobey believes that the health of eucalyptus forests would suffer without koalas. Although koalas have no competition in eating eucalyptus, many other species live in forests. By eating more than a kilo of eucalyptus leaves every day, each koala helps control plant growth, balance the forest ecosystem and support forest life for insects and birds.
Because koalas take a long time to digest the toxic leaves of eucalyptus, their droppings constantly replenish the surrounding soil, says Tobey. On the occasion when they come down from a tree to mate or move to another tree, they can also carry plant life with them and unknowingly help with pollination.
Consuming such a large amount of eucalyptus even helps reduce the amount of highly flammable eucalyptus that is available for burning during the fire season.
“They help eat fuel, even with so few koalas left, it’s hard to say how much effort they are helping now,” said Karen Marsh, a researcher at the Faculty of Biology Research at the National University of Australia.
Fires in koala areas usually occur in the spring and summer, but additional fires occur outside the standard season. Some fires have also increased, as scientists attribute, at least in part, to climate change and expect them to continue with changing weather patterns.
Koalas occur only in Australia. It is the sixth largest country in the world in terms of land, but 20% is desert, where average summer temperatures rise to 90 and low to 100 degrees Fahrenheit. Australia has warmed by 2.5 degrees since 1910, which is 0.6 degrees more than the global average increase. The last decade has been the hottest ever recorded in the country.
The more mega-fires that Australia experienced in 2019 and 2020 could significantly change the habitat of eucalyptus trees, says Michael Grose, a scientist at the Commonwealth Scientific and Industrial Research Organization, Australia’s national science agency. Some eucalyptus species could handle frequent burns and rebound quickly, while others can become extinct, potentially compromising the quality and diversity of trees available to koalas.
If koalas become extinct and no longer eat eucalyptus leaves, eucalyptus trees may evolve to be less toxic, Marsh says. If that happened, it could lead to an increase in the population among the various animals, which realized that they could now eat eucalyptus until the trees were decimated, followed by a sharp decline in the population of these species.
Researchers also believe that we can learn a lot from koalas in terms of their intestinal microbiome, which has evolved to digest the poisonous leaves of eucalyptus. Their “niche diet” probably affects the ecosystem, although no one knows exactly how, says Johnson. “Most likely they have their own parasites, with which they evolved together, so they would all disappear [if koalas go extinct]. ”
Koalas are also a monotypic species, meaning they are the last living species in their pedigree, says Johnson. “In terms of biodiversity, it would be a pretty significant loss of a single branch that has been hanging on it for a long time.”
Fortunately, because koalas don’t travel far from their favorite tree, a single species as a whole still has “a reasonable amount of genetic diversity,” Johnson said. This diversity could help protect koalas from certain health problems where other marsupials, such as the endangered Tasmanian Devil and the extinct Tasmanian Tiger, have not been so lucky.
Save the koalas
Koalas contribute much more than by enriching the surrounding soil and eating flammable leaves to reduce fuel consumption. According to the Australian Koala Foundation, Australia generates an estimated $ 3.2 billion in annual tourism revenue and 30,000 jobs.
“People come to Australia to see koalas. They’re a symbol of caring for the environment and caring for Australia’s biodiversity and uniqueness. So it’s hard to figure out what that means at all,” says Johnson. They appear on Australian tourist sites, are popular zoo leaders and were even the face of the Australian airline Qantas from 1967 to 1992. Their loss would lose a crucial piece of national identity.
With koalas listed as endangered in February, the Australian government has outlined conservation efforts, although some conservationists believe this is not enough. The government has invested $ 50 million in koala habitat restoration, disease prevention and medical research, and has updated the number of remaining koalas in the country.
In an effort to save the koalas, scientists are learning what they can from the Tasmanian Devil and the Tasmanian Tiger. Researchers at the University of Melbourne’s Thylacine Integrated Genetic Recovery Research Laboratory are even working to bring the Tasmanian tigers back from the dead. The biotechnology used for this project could spread to other species in problems such as koalas and prevent them from becoming extinct.
Regardless of the coalition conservation plans being worked on, Johnson urges you to hurry up so that no one needs to know exactly what will happen if the koalas become extinct.
“You can’t just keep making decisions that affect a habitat and expect nothing to happen to animals that rely on that habitat,” he says.
She is pleased that the Australian government is “relying on science”. But he says they shouldn’t wait long to put their ideas into practice.
“It’s a really satisfying and exciting thing to see a koala in the wild,” says Johnson. “Removing it would be quite sad. It’s an inadequate word to describe what it would be like not to see a koala in the wild.”