Australia's Mammals Are at Risk From Bird Flu. Here's What We Know.

Bird flu has reached mainland Australia for the first time. Two seabirds infected with the H5N1 strain were found in Western Australia last week, and a third infected bird was later found in South Australia. Scientists and wildlife workers have been preparing for this moment for more than two years. They are now working quickly to protect some of Australia's most endangered animals.

Bird flu mostly harms birds, but it can also infect mammals. Wildlife Health Australia's national coordinator, Tiggy Grillo, says marine mammals — like seals and sea lions — are at the greatest risk right now. Around the world, seal and elephant seal colonies have already been badly hurt by bird flu. Endangered seal and sea lion populations along Australia's coast are considered especially vulnerable.

Some of Australia's most famous marsupials are also at risk. Animals like Tasmanian devils and quolls are scavengers, which means they eat dead animals — including dead birds. A Virginia opossum in North America has already been killed by bird flu. That news alarmed scientists studying Australia's endangered marsupials, like Harriet Mills, a science program lead at Perth Zoo.

The Australian government has spent millions of dollars to help protect the most at-risk species. About 10 types of marsupials are receiving help, including Tasmanian devils, eastern and western quolls, and numbats. This money comes from a program called the Funding Preparedness initiative. Scientists want to be ready before the virus reaches these animals.

Tasmanian devils face some extra dangers from bird flu. They already have very low genetic diversity, which means their immune systems are not very different from one another. University of Sydney biologist Carolyn Hogg explained that low immune diversity is a serious problem when a new disease arrives. If one devil gets sick easily, many others likely will too.

Tasmanian devils have also been fighting a deadly cancer called devil facial tumour disease for years. This disease has already killed about 80 percent of devils in most areas where it has appeared. Researcher Andy Flies says this long battle may have weakened the devils' immune systems even more. There are now only about 10,000 to 15,000 Tasmanian devils left in the wild.

Devils could catch bird flu by eating infected birds that wash up on Tasmanian beaches. They can also travel up to 10 kilometres inland, which means they could carry the virus far from the coast. This could spread bird flu to parts of Tasmania that have not yet been affected. Several captive breeding programs in Tasmania have received funding to improve safety measures and keep the devils protected.

Western quolls, also called chuditch, live much closer to where the infected birds were found in Western Australia. They are listed as a vulnerable species, and nobody yet knows how they will react to this strain of bird flu. Dean Maxworthy, a wildlife project manager at Mulligans Flat in the ACT, says the chuditch's reaction will give clues about how eastern quolls might respond. Scientists across Australia are watching closely.

Eastern quolls have been extinct on mainland Australia for more than 60 years but have been brought back to a few wildlife sanctuaries. There are about 200 eastern quolls living at Mulligans Flat in the ACT. Workers there are rushing to finish building 14 protective enclosures so the quolls can be moved to safety if bird flu gets close. Once the enclosures are done, workers will wait until the virus nears before trapping and moving the animals.

Numbats are also being protected, even though they are not scavengers. Fewer than 1,000 numbats remain in the wild in south-west Western Australia, and Perth Zoo runs the only numbat breeding program in the world. The zoo has put roofs on its enclosures to stop wild bird droppings from falling onto the numbats' food. Staff are even exploring artificial diets to further reduce the risk of infection.

Scientists are also working on vaccines for marsupials, though none exist yet. Researchers are testing AI-powered bait dispensers that can recognise a specific animal and drop a vaccine-filled bait just for it. The same technology could one day be used to deliver a bird flu vaccine to wild animals. Experts say that having two years to prepare means Australia is better ready for bird flu than most other countries in the world.