Australia detects first suspected mainland case of H5N1 bird flu

A suspected H5N1 detection in a brown skua on Western Australia’s south coast has pushed Australia to the edge of a mainland incursion that could reshape wildlife, poultry and biosecurity planning far beyond one national park. The bird was found at Cape Le Grand National Park on June 14, died while in isolation, and a second sick bird, a giant petrel found nearby, was also being tested.

If confirmed, the case would end Australia’s run as the only continent without a mainland detection of the deadly H5N1 clade 2.3.4.4b strain. That matters because the virus has already driven mass die-offs in wild birds and mammals overseas since 2021, and has also spilled into poultry, dairy farms and farmworkers, creating a global template for how quickly an avian outbreak can become an agricultural and ecological crisis.

Western Australia Agriculture Minister Jackie Jarvis said further testing was underway to confirm the strain and that the suspected case was being treated seriously. She said a confirmed result would trigger a rapid, coordinated national response. The bird was described as a sub-Antarctic species, and officials said it was not normal for brown skuas to be on the south coast of Western Australia, a sign that the animal had turned up far outside its usual range.

The federal government has spent years preparing for this scenario. Murray Watt said Australia had been getting ready for the likelihood of H5’s arrival, calling a confirmed detection “sobering but not unexpected” given the virus’s spread around the world. The Albanese government said it had invested more than $113 million to strengthen preparedness, including an extra $11.2 million announced on June 18 to protect at-risk native species ahead of a possible outbreak.

Those measures include a national wildlife response arrangement, surveillance in wildlife and poultry, and response tools such as mobile laboratories, drones and trailers for remote settings. The Department of Agriculture, Fisheries and Forestry says the national management agreement for H5 high pathogenicity avian influenza in wildlife is meant to coordinate incursions quickly if the virus reaches native populations.

The stakes extend well beyond a single bird. Wildlife veterinarian Wayne Boardman warned that if H5N1 is confirmed in Australia’s wild bird populations, it could devastate native species, with endangered shorebirds, coastal raptors and Australian sea lions among the most vulnerable. Australia’s earlier 2024 bird flu package was valued at $95 million, a sign that the country’s biosecurity response has been escalating as officials increasingly treated an incursion as a matter of when, not if.