Bird flu kills 13,000 seal pups on remote Australian island

A pathogenic strain of bird flu killed more than 13,000 elephant seal pups after infecting a breeding colony on a sub-Antarctic volcanic island, Australian scientists said Thursday. Researchers found the remote Heard and McDonald Islands littered with seal carcasses when they arrived on a research expedition in October 2025.

Genetic testing confirmed the contagious H5 bird flu strain had killed seals, penguins and birds living on the rocky outcrop -- the first time it had been detected in one of Australia's external territories. Southern elephant seal pups were the worst hit by the outbreak, scientists from the Australian Antarctic Program said, with mortality in some seal "harems" as high as 97 percent.