HEARD ISLAND — More than 13,000 southern elephant seal pups died on Heard Island between August 2025 and January 2026 due to an outbreak of the H5N1 virus. Testing confirmed the presence of the H5N1 virus in penguins, seals, and petrels across subantarctic islands.

Government scientists conducted drone and ground surveys on Heard Island in October 2025 and January 2026. Seal pup mortality rates averaged 76 percent across the island, with one specific survey location reporting rates as high as 97 percent.

Six of the nine species on Heard Island tested positive for the H5N1 strain. Survey teams also observed several hundred dead adult king penguins. The subantarctic islands host over one million breeding seals and seabirds, and many of these species are listed on national and international conservation registries.

Genetic analysis of virus samples indicates the influenza was likely introduced to Heard Island in August 2025 by wildlife from the French subantarctic Crozet Islands, which are located approximately 1,800 kilometers away. The research paper authors state these observations represent the first detection in an Australian external territory.

The findings indicate the continued eastward movement of the virus around the sub-Antarctic. The Australian Antarctic Program monitors for bird flu in the Australian Antarctic Territory and on Macquarie Island, where no suspected cases have been reported.

The federal government allocated 11.2 million Australian dollars in the 2026-27 budget for H5N1 preparation. This funding is intended to address potential impacts on at-risk native species on the Australian mainland. Australia's environment minister, Murray Watt, addressed the situation and stated, "For now we're free from the serious and contagious H5 bird flu, but as it continues to spread globally, we must be realistic about the likelihood of an incursion here, and plan accordingly."