Scientists say a virus has devastated an ultra-remote island near Antarctica, killing more than three quarters of newborn southern elephant seals, which is around 13,000 pups
A devastating bird flu outbreak has torn through one of the world’s most untouched wildlife havens. Scientists have consequently confirmed that H5N1 wiped out more than three quarters of newborn southern elephant seals on Australia’s ultra-remote Heard and McDonald Islands in the Southern Ocean.
The deadly bird flu strain has ripped through one of the planet’s most isolated wildlife strongholds. Researchers are reportedly saying the outbreak has killed around 13,000 southern elephant seal pups and also hit penguins and seabirds on the Islands near Antarctica.
The barren volcanic islands – roughly 2,485 miles (4,000 kilometres) south-west of mainland Australia – have long been seen as a pristine sanctuary for breeding birds and marine mammals.
But drone surveys by the Australian Antarctic Program, carried out in October and January, reportedly captured what senior research scientist Jarrod Hodgson called “sobering” scenes of seal pup carcasses scattered across the grey shorelines. Scientists estimate pup mortality reached 76% from a cohort of around 17,000 born on the islands, with one high-density area recording a concentrated death rate of 97%.
And Hodgson warned there are still big unknowns about the longer-term fallout, saying: “The thing we don’t know from our surveys so far is what the impact was on the breeding adult population of southern elephant seals.” The damage was not limited to seals, CNN reported.
Data gathered in January found “several hundred” adult king penguins on Heard Island had died, with researchers noting the mortality appeared higher than normal levels. Wildlife biologist Julie McInnes said the outbreak marks a grim milestone for Australia’s remote territories.
She warned: “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.” McInnes, who is lead author on the research, added: “Our results show a similar pattern to other sub-Antarctic islands, such as South Georgia, where elephant seals have been hardest hit.”
Genetic analysis suggests the virus may have arrived via wildlife from the French sub-Antarctic Crozet Islands, around 1,800km away, with researchers believing it likely reached Heard and McDonald around August 2025.
As of February, researchers noted there had still been no confirmed cases of the H5N1 strain on the Australian mainland or in New Zealand, despite the virus spreading widely among birds globally and infecting some mammals.
The findings were shared on the scientific preprint site BioRxiv and have not yet been peer reviewed.
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