Australia confirms first deadly H5N1 bird flu case in a native seabird as total detections climb to 12

First native case raises concern

On Friday, federal agriculture minister Julie Collins confirmed that a greater crested tern found dead at Robe on South Australia’s Limestone Coast had tested positive for the deadly H5N1 strain. Laboratory testing by Australia’s national science agency (CSIRO) identified the virus, marking the first infection in a native Australian seabird. All previous detections had been in migratory subantarctic species, mostly giant petrels, found along the coasts of South Australia, Western Australia and New South Wales.

While this, of course, is a concerning development, it is not unexpected and is another sign that our strong biosecurity system is working.

Collins explained that the coastal tern’s habitat overlaps with the migratory routes of seabirds known to carry H5. Scientists are now working to trace the infection pathway, seeking to understand how the local bird became infected and whether transmission among native populations is occurring.

Surveillance and response efforts

The South Australian government is leading the on-ground response, which includes intensive surveillance to assess whether the virus has spread further into local wildlife. Earlier this week, the state completed the largest aerial survey of its coastline, islands and reefs in 40 years, finding “no widespread evidence of sick or dead seabirds or seals,” The Guardian reported.

What we do know is that this is a coastal seabird that has an overlapping coastal range with migratory seabirds that have previously tested positive for H5.

Collins emphasised that there was still no evidence of mass mortality events or infections in poultry or the broader agricultural sector. The federal government reiterated that Australia is well prepared and is coordinating with states.

Rising detections and global background

On the same day, authorities confirmed two additional H5N1 infections in South Australia and one in Western Australia, bringing the total number of confirmed or presumed detections across the country to 12. Australia, long the last continent to remain free of the virus, recorded its first detection in late 2025 on the sub-Antarctic Heard Island, roughly 4,100 kilometres from the mainland. In June this year, the country confirmed its first mainland cases, all in migratory seabirds.

The highly pathogenic H5N1 strain has been circulating globally for several years, causing mass die-offs in wild bird populations and occasional spillover into mammals. It spreads through body fluids, droppings and feathers, and can survive in the environment for months.

Risk to agriculture and humans

The government maintained that the risk to human health remains low. In a statement, it urged poultry producers and backyard bird owners to strengthen biosecurity measures and advised the public not to handle sick or dead birds and to report any unusual animal deaths.

Australia is well prepared to respond quickly.

Experts quoted by The Independent warned that if the virus becomes established in wildlife, it may become impossible to eradicate, potentially turning into an endemic disease. Typical symptoms in birds include drooping, puffiness, difficulty standing or walking, breathing problems, and abnormal head or neck posture, often followed by sudden death. Only laboratory testing can confirm the virus.