Bird flu threat looms over penguins, seals
Research by scientists from the Australian Antarctic Program has shown the catastrophic impact of H5 bird flu on seal and penguin populations on Heard and McDonald islands.
How at risk are the island's population of seals and penguins?
The H5 bird flu virus was detected in crested terns on Seal Rocks last week, and over the weekend, in one little penguin.
Seal Rocks is home to one of Australia's most significant Australian fur seal colonies for approximately 16,000 seals. While H5 avian influenza is primarily a disease of birds, international outbreaks have demonstrated that seals and other marine mammals can also be affected.
As a result, the Nature Parks confirmed it has increased monitoring of the Seal Rocks colony, including regular drone surveillance, to assess colony health and identify any emerging impacts.
Phillip Island supports some of Australia's most significant wildlife populations, including the world's largest little penguin colony, one of the world's largest short-tailed shearwater colonies, a major Australian fur seal colony and internationally recognised wetlands that support migratory bird species.
However Nature Parks it said it was too early to determine the full impact of the virus on wildlife populations on the island.
"The detection of H5 avian influenza on Phillip Island is concerning, but it is not unexpected. Phillip Island Nature Parks has been preparing for the potential arrival of the virus since 2023 through wildlife disease response planning, enhanced surveillance, biosecurity measures and wildlife health research," said CEO Catherine Basterfield.
Overseas
Scientists from the Australian Antarctic Program have been studying the impact of the H5 bird flu virus on wildlife on Heard and McDonald islands.
Six species have tested positive for the virus, including southern elephant seal, king penguin, gentoo penguin, Antarctic fur seal and South Georgia diving petrel.
A recent article on the antarctica.gov.au, stated analysis of drone surveys taken on two voyages in October 2025 and January 2026 reveal very high mortality in southern elephant seal pups and elevated mortality in king and gentoo penguins.
"Analysis of data collected in October estimated average pup mortality was 76 per cent in the final surveys and as high as 97 per cent in one area," the article stated.
"Total pup production was estimated at around 17,000 and island-wide mortality was estimated at around 13,000 pups on Heard Island."
The scientists said the results showed a similar pattern to other sub-Antarctic islands.
Professor Anne Peters, a specialist in the behaviour ecology and conservation of birds, Deputy Head of School of Biological Sciences, Monash University, agreed many local wildlife populations were vulnerable.
"Unfortunately, very many of our birds but also mammals, for example seals and sea lions, but also dolphins, are known to be at great risk of mass mortalities. Waterbirds, shorebirds and scavengers have been shown to be vulnerable in other continents, with extremely distressing mass mortality events, and risk of extinctions for already highly threatened species."
Professor Melodie McGeoch, School of Biological Sciences and Securing Antarctica's Environment Future, at Monash University said researchers, citizen scientists and member of the public had a critical role to play in responding to the H5 virus.
"Early detection and rapid response depends on having eyes on the ground everywhere," she said.
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