Antarctic penguins are now dying from the H5N1 strain of bird flu

Scientists have confirmed the first known deaths from a contagious and highly pathogenic avian influenza strain called H5N1 in some Antarctic penguin species. H5N1 first arrived in the Antarctic in late 2023 and the virus has now been confirmed in some Gentoo penguins that were found dead in the Falkland Islands. Over 20 Gentoo chicks have been reported dead from the virus or are showing symptoms of bird flu. Other Gentoo penguins have been reported sick or dead at this same location, according to the Falkland Islands Department of Agriculture.

[Related: Seal pup die-off from avian flu in Argentina looks ‘apocalyptic.’]

Possible case in King penguins

Additionally, at least one King penguin is suspected to have died from bird flu. According to the Antarctic Wildlife Health Network which is part of the Scientific Committee on Antarctic Research, this would be the first death from bird flu in this species. The suspected case was reported on South Georgia island, about 900 miles east of the Falklands. However, the extent of the virus spread is still being reviewed and this death has yet to be officially confirmed.

“We have no conclusive evidence that king penguin populations in South Georgia have been impacted by the virus,” Laura Willis, the chief executive of the government of South Georgia and the South Sandwich Islands, told The New York Times in an email. “We are monitoring the situation across the islands and apply a precautionary approach, which includes closing some sites to allow further investigations to take place.”

Colonies at risk of disease

The penguins in the Antarctic likely do not have any existing immunity to this pathogenic virus. They also breed in large colonies with cramped conditions, so it can spread rapidly if one bird is infected. More than 500,000 seabirds have died since the virus arrived in South America last year, with pelicans, boobies, and penguins among the hardest hit animals. Chile reported the deaths of thousands of Humboldt penguins. Mass deaths of elephant seals have since been reported, as well as increased deaths of kelp gulls and brown skua.

“The arrival of this H5N1 virus in the Antarctic towards the end of last year rang alarm bells because of the risk it posed to wildlife in this fragile ecosystem,” molecular virologist at the MRC-University of Glasgow Centre for Virus Research Ed Hutchinson told The Guardian. “And while it is very sad to hear reports of penguins dying … it is unfortunately not at all surprising.”

No infections have been reported on the Antarctic mainland, but the virus could be currently spreading there undetected.

In 1996, H5N1 was first detected in China. The virus had been largely confined to domesticated birds for several years, but has been spreading quickly in wild populations since 2021. Bird flu spreads through air droplets and bird feces. According to the Wildlife Conservation Society, it has been exacerbated by alterations to bird migration schedules due to human-caused climate change and repeated re-circulation in domestic poultry.

[Related: Thriving baby California condor is a ray of hope for the unique species.]

Scientists confirmed that the virus jumped to wild mammals in May 2022 and it has since been detected in dozens of mammals including pumas, foxes, skunks, and brown bears. Almost 96 percent of elephant seal pups living at three breeding sites in Patagonia, Argentina died from bird flu in 2023.

It also continues to spread through wildlife populations on the other side of the world. In December 2023, officials in Alaska confirmed that a polar bear had died of H5N1 in the Arctic for the first time.

The World Health Organization has urged public health officials to prepare for a potential spillover to humans in the future. Initially, scientists thought that mammals could only catch the virus through contact with infected birds. While cases of humans getting infected and seriously ill from bird flu are rare, the more it spreads among mammals, the easier it will be for the virus to evolve to spread.