Bird flu kills thousands of baby seals on remote Australian island

Bird flu has devastated wildlife on Australia's remote Heard Island and McDonald Islands, killing an estimated 13,359 southern elephant seal pups. This represents more than three-quarters of the pups born on Heard Island, a significant blow to a species already listed as vulnerable.

The highly pathogenic avian influenza (HPAI), also known as bird flu, was first detected in the territory in October 2023. Initial observations found hundreds of dead pups, but a later analysis in January revealed the true scale of the mortality. Researchers estimate that some seal harems lost up to 97 percent of their pups, with the death toll ongoing during their observations.

The virus also impacted other species, including king penguins, gentoo penguins, and Antarctic fur seals. While mass mortality was only observed in southern elephant seals, elevated death rates were also seen in king and gentoo penguins. Scientists believe the virus likely arrived in August 2023 via infected wildlife from the nearby Crozet Islands.

Researchers utilized drone surveys, ground searches, and genetic analysis to gather data. Drone flights covered 1,600 kilometers, providing crucial information that ground searches could not match. The findings, published in BioRxiv, have not yet been peer-reviewed. Scientists are concerned that if HPAI spreads to other sub-Antarctic areas, such as Macquarie Island, it could pose a "potentially catastrophic threat" to the region's vulnerable wildlife, which often gathers in large, dense colonies ideal for rapid viral transmission.

“

The emergence of HPAI poses a severe and potentially catastrophic threat to the wildlife of the Southern Ocean and sub-Antarctic environments, where large, dense breeding and moulting aggregations of already vulnerable species, such as albatrosses, penguins, elephant seals and fur seals, create ideal conditions for rapid viral transmission.