More than 13,000 seal pups die on remote Australian island amid bird flu outbreak

The deadly impact of the H5N1 bird flu on Heard Island, a subantarctic island. Photograph: Australian government

Genetic analysis of samples indicated the deadly influenza was probably introduced via wildlife from the French subantarctic Crozet Islands – about 1,800 km away – with an estimated arrival in August last year, according to the paper.

“These observations of H5 bird flu at Heard Island and McDonald Island are the first detection in an Australian external territory and show the continued eastward movement of the virus around the sub-Antarctic,” co-lead author wildlife biologist Dr Julie McInnes said.

The Australian Antarctic Program continued to monitor for signs of bird flu in the Australian Antarctic Territory and on Macquarie Island, which have not had any suspected cases.

Australian government scientists conducting drone and ground surveys in October 2025 and January 2026 discovered the mass deaths of elephant seal pups. Photograph: Jarrod Hodgson

On Thursday, the federal government said it had allocated an additional $11.2m in the 2026-27 budget to prepare for potential impacts of H5N1 on at-risk native species on the Australian mainland.

“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,” said the environment minister, Murray Watt.

Dr Michelle Wille, an expert in avian influenza viruses at the University of Melbourne, said the results of the surveys were “really devastating”, but consistent with impacts elsewhere in the subantarctic.

Wille, who is not an author of the paper, said early risk assessments for Australia had focused on the potential introduction of H5N1 from the north. But the movement of the virus across vast distances in the subantarctic made the risk of entry to Australia via the south more plausible.

Public reporting remained “extremely important”, she said. “If people see sick or dead birds or marine mammals its really important that they report via the emergency animal disease hotline (1800 675 888).”