Australian scientists have found that a bird flu outbreak on Heard Island has caused massive mortality among seal pups, with deaths reaching nearly 77% of the population and as high as 97% in some breeding colonies.

Researchers analyzed drone imagery, biological samples from nine animals and genomic data collected between October 2025 and January 2026 on Australia's remote Heard and McDonald Islands in the southern Indian Ocean.

The study detected the H5N1 strain of avian influenza in six groups of animals, including king penguins, gentoo penguins, southern elephant seals and Antarctic fur seals.

According to the findings, 13,359 of the island's 17,364 seal pups died from the virus, representing a mortality rate of 76.9%.

"Mortality reached 97% in some seal colonies"

Researchers said that in one breeding area, mortality among seal pups reached 97%, highlighting the severity of the outbreak.

They also reported that deaths among penguin populations were higher than previously expected, raising concerns about the long-term impact of the virus on the islands' wildlife.

Scientists believe the virus first reached Heard and McDonald Islands in August 2025.

"More than a million seabirds and seals inhabit the islands"

The remote subantarctic islands are home to more than one million seabirds and seals and are recognized as one of the world's most important wildlife habitats.

Dead seal pups believed to have succumbed to bird flu were first discovered on the islands in 2025, prompting investigations into the spread of the virus.

Research conducted in January indicated that southern elephant seal pups were among the species most heavily affected, while king and gentoo penguins were also found to have been impacted by the outbreak.

The findings underscore growing concerns among scientists over the spread of highly pathogenic avian influenza to remote ecosystems and its potentially devastating effects on wildlife populations. (ILKHA)