Spring in the Australian state of Queensland is a time of crisis for many wild animals, and Currumbin Wildlife Hospital is a haze of fur and feathers.
A groggy black swan emerged from the X-ray room, shaking its head with its long neck. The flying fox was wearing a small anesthetic mask. An injured lorikeet was crying in its cage. (“Very angry,” the sign warned.)
“We're looking at everything,” says Dr. Michael Pine, the hospital's senior veterinarian. The day's schedule also included three eagles, two carpet pythons, a blue-eared honeycreeper, a short-eared possum and, according to Dr Pine, “a heap of koalas”.
More than a dozen koalas were recuperating in an outdoor enclosure with their woolly arms wrapped around the trunk of a eucalyptus tree. Wards were often full. In 2023, the hospital admitted more than 400 koalas, which is four times more than in 2010.
This surge is primarily driven by the spread of chlamydia, a devastating bacterial infection. However, the hospital was also seeing an increase in the number of koalas suffering from trauma, including from cars and dogs. The koalas arrived starving and dehydrated during the drought. A burnt koala appears after a bushfire. Occasionally, a koala would appear that had been injured by a cow.
“That's why they're endangered,” Dr. Pine says. “Everything is against them.”
Koalas have long been a symbol of Australia, but unfortunately they have become a symbol of the country's biodiversity crisis. Animals are threatened by deforestation, climate change and infectious diseases. Together, these forces put koalas at real risk of extinction. Koalas are notoriously difficult to count, but scientists estimate their numbers have plummeted by as much as 80 percent in some places.
“We don't know what the point of no return is,” said Tanya Pritchard, senior manager for species recovery and landscape restoration at the World Wildlife Fund Australia. She said: “So we need to act pretty quickly.”
Scientists and conservation groups are giving koalas everything they can. Some are pursuing time-tested traditional strategies, such as protecting koala habitat and advocating for stricter protection laws.
Other companies are trying more experimental approaches, from koala probiotics to tree-planting drones. Many of these projects are in their early stages, and none are complete solutions. However, given the range of threats facing koalas, we may need to deploy all available tools to save them.
“Every koala is important at the moment,” Ms Pritchard said.
Here we introduce some tools that are currently under development.
get a shot in the arm
Chlamydia, a common sexually transmitted disease in humans, is also widespread in the animal kingdom. It's unclear how koalas first became infected, but one possibility is that the marsupials picked up chlamydia from livestock feces.
The disease can be spread through sexual contact and from mother to joey, and is alarmingly prevalent in parts of Australia. Chlamydia can cause urinary tract infections, blindness and infertility, suggesting the situation may be even worse than the decline in koala numbers suggests. “How many koalas that have been rendered infertile by chlamydia will never be able to breed again?” Dr Pine said.
Scientists are currently testing a new chlamydia vaccine on koalas in the wild in collaboration with Currumbin Wildlife Hospital in Currumbin, Australia. Queensland University of Technology immunologist Ken Beagley, who led the vaccine development, said the vaccine had produced “really impressive results” so far.
In two ongoing studies, more than 300 wild koalas have been vaccinated, with many of the vaccinated female koalas giving birth to healthy koalas, and some of them giving birth to their own koalas. said Dr. Beagley. “It was much better than we expected,” he said of the result.
Still, it is difficult to vaccinate thousands of wild koalas with current vaccines, which require two doses given 30 days apart. Dr Beagley and his colleagues are therefore developing a delayed-release vaccine implant that can be injected subcutaneously when koalas receive their first vaccination. Over several weeks, the small capsule slowly absorbs water and ruptures, delivering the second dose.
Please give me good microorganisms
Koalas are famous for being picky eaters with very unusual tastes. “They're eating eucalyptus leaves, which are high in fibre, low in protein and high in toxins, which is very bad,” said Michaela Brighton, a molecular ecologist and microbiologist at the University of Queensland.
To survive on eucalyptus, it requires a cooperative community of gut microbes to help digest the leaves. Dr Brighton's research suggests that these microbial communities are so finely tuned that they may determine which of the many eucalyptus species scattered across Australia are available to individual koalas. It suggests that there is. This microbial specificity may explain why koalas sometimes fail to diversify their diets even in the face of starvation.
In a 2019 study, Dr Brighton showed that by transplanting feces from koalas that had eaten different types of eucalyptus, they could alter their microbiomes and expand their diets. (To perform the transplant, Dr. Brighton packed a fecal sample from the donor koala into a small capsule and administered it orally.)
Now she wants to use the same approach to maintain microbial balance in koalas taking antibiotics, the front-line treatment for chlamydia. This drug can disrupt the gut microbiome and cause the koala to stop eating altogether, with potentially fatal consequences. Dr Brighton, who works with Currumbin Hospital and other wildlife hospitals, said: “It's a tough call to get animals back on their feet and in many cases this isn't possible.”
Dr Brighton developed a technique to freeze-dry faecal samples from healthy koalas, producing long-term shelf-stable capsules that can be given to koalas containing chlamydia as a type of oral probiotic. Unfortunately, early trial results suggested that administering the capsules was stressful for sick koalas. So Dr. Brighton is now turning freeze-dried fecal samples into a powder that can be added to other nutritional supplements animals are already taking.
deploy a drone
Koalas are sedentary, arboreal animals that are difficult to find in the wild, making it even more challenging to track population status, identify critical habitat, and protect animals from threats. Masu.
Grant Hamilton, a quantitative ecologist at the Queensland University of Technology, has developed a new koala spotting system that uses artificial intelligence. Drones equipped with thermal cameras fly over trees, searching for pockets of body heat hidden beneath the canopy. Machine learning algorithms quickly process this footage and tally the number of koalas. Scientists then use statistical models to estimate the total number of koalas in a given area.
Scientists are now teaching local conservation groups how to fly drones in their own neighborhoods. Dr Hamilton and his colleagues will analyze the data and help these organizations identify important koala habitat that could benefit from conservation and restoration. “We can use AI to help people manage their backyards and parks,” he said. “That's a really exciting idea.”
World Wildlife Fund Australia is currently running a campaign to save or plant 2 billion trees by 2030, and is experimenting with the use of drones for habitat restoration. One tree-planting drone can rain approximately 40,000 seeds across a landscape over an eight-hour period.
Drones aren't suitable for all environments, but they offer a way to “scale up this work,” Pritchard said. “To me, it's a little bit symbolic of our own predicament,” she added. “If we can't save the koala, our most important and most beloved species, what does that mean for our own situation and the health of our own habitat?”
Harnessing the power of the sun (and people)
Despite the threats they face, koalas have one thing they can do for themselves. “They are one of the cutest animals on the planet,” says conservation ecologist Dr Romane Cristescu from the University of the Sunshine Coast.
To capitalize on people's natural love for koalas, she and her colleagues are developing a series of technological tools, including solar-powered location-tracking ear tags that send data to a mobile app. The app, which is still being tested, is aimed at helping Australians know which koalas live in their neighbourhoods, including “where they're going, who they're meeting, their children, their boyfriends”, Dr Christescu said. “We're going to tell people, 'Look, that koala has life, too.'”
Dr Christescu hopes that people who are attached to their local koalas will be more likely to support conservation efforts and change their own behavior, such as choosing not to cut down trees in their gardens. “We feel more empathy for the koala because it has a name and a story,” she says.
The app also encourages users to record koala sightings and report sick koalas, and that data can be sent to scientists and wildlife conservation teams, she said.
Ear tags could be used for other purposes, said Dr Christescu, who is also leading a research program using trained dogs to sniff out koalas and their faeces. After devastating bushfires in Australia in 2019 and 2020, her team used dogs and drones to find and rescue injured koalas. Ear tags that track location could provide a faster way to find koalas at risk, she said.