Highly pathogenic H5N1 avian influenza has been confirmed as the cause of the first documented wildlife die-off on the Antarctic continent, killing more than 50 south polar skuas during the summers of 2023 and 2024, according to a study published this week in the Nature journal Scientific Reports. The research, led by teams from Erasmus MC in the Netherlands and the University of California, Davis, detected the virus at three sites on the Antarctic Peninsula including Hope Bay, Devil Island, and Beak Island, where a mass die-off occurred. The findings confirm that the devastating H5N1 panzootic, which has already killed hundreds of millions of birds worldwide, has now reached Earth's last pristine continent.
The expedition surveyed 10 locations across the South Shetland Islands, northern Weddell Sea, and Antarctic Peninsula in March 2024. Infected skuas displayed severe neurological symptoms including twisted necks, abnormal stretching, and circular walking or swimming patterns, with some birds stumbling blindly or falling from the sky. Researchers performed necropsies on gentoo penguins, Adelie penguins, and Antarctic fur seals found dead at the same sites, but H5N1 was not confirmed as the cause of death in those species, suggesting skuas may be serving as the primary vector for the virus's spread across the continent.
Skuas are predatory seabirds and scavengers that play a critical ecological role in Antarctic food webs by cleaning up carcasses, but this same behavior makes them particularly vulnerable to contracting and spreading H5N1. The virus was first identified in 1996 on a domestic goose farm in Southeast China and spread uncontrolled through the global poultry industry before jumping to wild birds, progressively reaching Europe, the Middle East, Africa, North America, South America, and finally Antarctica in early 2024. The same lineage has decimated elephant seal and sea lion populations in Argentina, killed over 400 million poultry globally, and infected dairy cows, mink, foxes, bears, and otters.
Corresponding senior author Thijs Kuiken, a professor at Erasmus MC, warned that everything points toward the virus spreading further and that without active monitoring, the scientific community will not know the true extent of the damage. He emphasized that the virus was allowed to slip through when it first emerged in the poultry industry decades ago, and the consequences are now being felt in the most remote ecosystems on Earth. The study stresses that updated population surveys for south polar skuas are urgently needed, as the last comprehensive census was conducted in the 1980s when approximately 800 breeding pairs were counted in the study area.
The arrival of H5N1 in Antarctica adds to a growing list of threats facing the continent's fragile ecosystems, which already include climate change, increasing tourism, invasive species, overfishing, and pollution. Researchers are calling for enhanced surveillance programs and international coordination to track the virus's spread among Antarctic wildlife, particularly as warming temperatures may alter migration patterns and bring infected species into closer contact with vulnerable populations. The study underscores that approximately 1,000 people have been infected with H5N1 globally, with a fatality rate of around 50 percent, raising concerns about the broader public health implications of the virus's continued expansion into new environments.
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