25 November 2025


Testing has confirmed the presence of the H5 high pathogenicity avian influenza (H5 bird flu) in samples collected from southern elephant seals on Heard Island – a sub-Antarctic Australian external territory.

Heard Island is extremely remote, located more than 4000km south-west of Perth and 1700km north of Antarctica in the Southern Ocean.

Given the known presence of this virus nearby on the French Kerguelen and Crozet sub-Antarctic islands, these results are not unexpected, and the detection does not substantially increase the risk to Australia from current levels.

While Australia’s H5 bird flu freedom status remains unchanged, the test results serve as a reminder of the importance of ongoing vigilance, coordinated biosecurity measures, and preparedness across governments, industry, and conservation partners.

The Albanese Labor Government is investing more than $100 million to strengthen bird flu preparedness and enhance national response capability – including towards the delivery of rapid response equipment in every state and territory.

Samples were collected after Australian Antarctic Program scientists observed unusual levels of mortality in elephant seals during a recent management voyage to Heard Island.

Testing was conducted by the CSIRO’s Australian Centre for Disease Preparedness in Geelong after the samples were securely packaged and arrived in Australia on Monday 17 November aboard RSV Nuyina.

Testing confirmed the presence of H5N1 high pathogenicity avian influenza clade 2.3.4.4b virus in these samples.

There were no observations of unusual mortality in other species present on the island, including penguins and other seabirds.

A second voyage to Heard Island, scheduled to arrive late December, will be important to gather further information about wildlife health.