First bird flu deaths reported in Antarctic penguins

The well-known black and white birds face numerous threats, including climate change, pollution and commercial fishing. Three species of Antarctic penguins (emperor penguins, southern rockhopper penguins and macaroni penguins) are classified as vulnerable or near threatened.

Before H5N1 arrived in the Antarctic region last fall, highly pathogenic avian flu viruses had never before been documented in the area. That means the penguins likely have little immunity. And because they breed in large, crowded colonies, once a penguin becomes infected, the virus could spread quickly and cause mass mortalities. (As the virus spread across South America last year, Chile reported the deaths of thousands of Humboldt penguins.)

The extent of the virus’s spread in Antarctic penguin populations remains unclear.

In the Falkland Islands, some gentoo penguins appeared sick or lethargic, and a small number showed neurological symptoms, before they were found dead, Heathman said. The virus has not yet been confirmed in any other local penguin species, he said, but testing is being done on rockhopper penguins.

At least one suspected case has also been reported in king penguins on South Georgia, another British territory, according the Antarctic Wildlife Health Network, which is part of the Scientific Committee for Antarctic Research.

That report was based on a single dead king penguin, and researchers have not seen an increase in penguin deaths there, said Laura Willis, executive director of the government of South Georgia and the South Sandwich Islands. “We are monitoring the situation on all islands,” she said.

The virus, which first emerged in 2020, has taken an unprecedented toll on wild birds and mammals. After the virus was detected at the tip of South America last year, OFFLUA global network of flu experts warned that the pathogen could spread to Antarctica next.

The Antarctic region provides critical breeding territory for more than 100 million birds, as well as seals, sea lions and other marine mammals. If the virus reached the region, its impact on those animals “could be immense,” OFFLU said in a statement last August.

Just two months later, the virus was detected in brown skuas in South Georgia, the first cases in the region. Since then, infections have been confirmed in many other bird species, as well as elephants and fur seals. These marine mammals also breed in large colonies and suffered significant losses as the virus spread across South America, where tens of thousands of seals and sea lions were reported dead. Scientists fear the same fate could befall Antarctic seals as the virus spreads.

No infections have yet been reported in continental Antarctica, although experts have said the virus may already be spreading undetected there.