Australia's mammals are at risk of bird flu. This is what we know

Why bird flu poses a high risk to many Australian native mammals Wed 24 Jun 2026 at 5:17pm In short: Some of Australia's endangered mammals and marsupials may be at risk from a deadly strain of bird flu. Little is known about the impact of H5N1 on marsupials, but experts are worried as the only species found in North America is one of many mammals around the world to have died. What's next? Conservationists are moving to protect susceptible species. It was always a matter of when, not if, bird flu would arrive on mainland Australia. Australia was free of H5N1 bird flu until two seabirds confirmed to have the virus were discovered in Western Australia last week. Since then, a third bird infected with the virus has been detected in South Australia. But while birds are the most likely victims of the virus, for more than two years, conservationists across Australia have been planning for how they will protect endangered mammals. Wildlife Health Australia national coordinator Tiggy Grillo said it could affect many of Australia's mammals. Loading..."Marine mammals are really the ones in the firing line … so we're certainly worried about our marine mammals … specifically seals and sea lions," Dr Grillo told Lab Notes on Radio National. Sea lion and elephant seal colonies are among a long list of mammals that have been severely impacted by bird flu as it has swept around the globe, and endangered populations in mainland Australia are considered high risk. "And then the other species that could be potentially at risk in Australia are the ones that scavenge on birds or eat birds." Many of Australia's most iconic marsupials, such as Tasmanian devils and quolls, are scavengers. The Virginia opossum, which lives on the North American continent, is the only known marsupial to have been killed by bird flu so far. It has left experts like Perth Zoo science program lead Harriet Mills concerned for Australia's marsupials, especially those that are endangered. "It's really a big unknown … because very few marsupials have been exposed to bird flu because most of them are here in Australia,"Dr Mills said. The not knowing is part of why the federal government has spent millions through the Funding Preparedness initiative to assist projects that will protect some of the most vulnerable species. These include about 10 species of marsupials such as Tasmanian devils, western and eastern quolls, and numbats. Tassie devil's low immunity a risk Scavenging behaviour, in combination with low population numbers and genetic diversity, could put Tassie devils, along with a number of other marsupials, at significant risk, according to an assessment of the risk posed to Australia's scavenger animals co-authored by University of Tasmania wildlife immunologist Andy Flies. In addition, he says, a recent pre-print study he worked on, which is yet to be peer reviewed, shows Tassie devils may have a more inhibited immune response. "Some of their key immune genes look like they've been depleted by fighting off the devil facial tumour, and the worry there is if that makes them more susceptible to influenza," Dr Flies said. University of Sydney population biologist Carolyn Hogg said Tasmanian devils lacked diversity in the genes used for detecting new diseases in their bodies. "Low immune diversity in any species is a problem when you have a novel disease arrive in a country," she said. With an already small population, the concern is that the virus could spread quickly during breeding season, with less of a chance that the species could recover, Dr Flies said. "[Facial tumour disease] has already knocked their population down by about 80 per cent in most places where the tumour is," he said. "So it's already a small population, only about 10,000 to 15,000 devils left in the world in the wild." The risk for Tassie devils is if they eat the birds that either wash up or die on Tasmanian shores. "The devil coastal populations near rocky shores that seabirds like to nest and rest on are the ones likely to be exposed,"Professor Hogg said. Tasmanian devils can also travel long distances, Dr Flies said. "So if they eat a bird on the coast, they might go inland by 10 kilometres … that could bring the virus into other parts of the state that might not have initially had an infection," he said. A number of captive breeding programs in Tasmania have received funding to improve biosecurity control. Quolls close to outbreak While Tasmanian devils are still very far away from where the two infected migratory birds were found in Western Australia, there is a scavenger much closer to the site — quolls. Specifically, the western quoll or chuditch, which is listed as a vulnerable species. The WA government has received funding for planning preparedness towards the species, but it is not known how the animals will respond if they are exposed to this strain of bird flu. Conservationists in eastern states, such as Dean Maxworthy, wildlife project manager at Mulligans Flat in the ACT, are also watching closely. Mulligans Flat is one of only a few reserves that have reintroduced the chuditch's Tasmanian cousin, the eastern quoll, back into mainland Australia. "Seeing what happens and how the chuditch responds … will give us a bit of an idea more on what is to be expected with the quolls here," Mr Maxworthy said. Eastern quolls, which are listed as endangered, have been extinct on mainland Australia for more than 60 years. They've been successfully reintroduced into different wildlife sanctuaries in the ACT and Victoria through a breeding program based in Tasmania. But even there, "[eastern quoll] populations have disappeared in some places of Tasmania already," Dr Flies said. Funding was granted for Mulligans Flat to prepare for bird flu because of a direct threat to the quolls in the sanctuary. Until the most recent detection in WA, scientists had thought the most likely route for bird flu into Australia was from the north. One potential carrier, the Latham's snipe, makes a stopover in Mulligans Flat during its migration. There are 200 quolls in the sanctuary, but they have only received enough funding to create 14 enclosures. "We're never going to be able to capture all of them. This is literally an insurance population,"Mr Maxworthy said. The enclosures aren't finished just yet at Mulligans Flat, so for Mr Maxworthy and ACT Parks, it's all hands on deck to get them finished. Once completed, they'll wait until bird flu reaches closer states to begin trapping the quolls. WA numbats also threatened Although numbats are not scavengers, Dr Mills said Perth Zoo had still taken similar precautions to those at Mulligans Flat. With fewer than 1,000 animals left in the wild in south-west WA, the species is listed as endangered. Perth Zoo is the only place in the world with a breeding program for the animals. "We've gone from having open-air enclosures to having them now roofed, and that's to try to protect them from the faeces of wild birds falling into the enclosure," Dr Mills said. The concern is that scat will fall onto termites or other food that the numbats eat. Along with extra biosecurity measures, including quarantining and cleaning of equipment, Dr Mills and the team at Perth Zoo was looking at artificial diets for the numbats to limit their contact with potential bird flu. "So, using egg powder, which we can source now and store long term as a backup," Dr Mills said. "We haven't seen disease issues as a major threat to numbats before. So this will be a first if they do prove to be susceptible." What about vaccines? No vaccines are available for any marsupials. But should one become available in the future, scientists such as Dr Flies are experimenting on ways to deliver oral vaccines to wild animals. "I think having a contingency plan in place with a preventative mechanism, like a vaccine, is really key because once it starts … it's hard to play catch-up," he said. At the moment, the trials have focused on vaccinating animals for devil facial tumour disease, but he said the technique could be adapted for a vaccine that targeted bird flu. "We've developed AI bait dispensers that can say, 'That's a devil, drop the bait', so it gets vaccinated," Dr Flies said. "But for influenza, you'd put influenza targets in, and it's pretty easy to swap DNA in and out for the viruses." Even in the uncertainty, experts say that having two years to plan a response to the H5N1 strain means Australia is more prepared for bird flu than most. "While there's a bit of anxiety, I think there's also a feeling that we are as well prepared as we can be,"Dr Mills said. Anyone who sees a dead or sick bird is asked not to touch it and report it to the Emergency Animal Disease Hotline on 1800 675 888.