H5N1 Bird Flu Reaches Antarctica: Mass Skua Die-Off Confirmed

For the first time, the highly pathogenic avian influenza virus H5N1 has been confirmed as the cause of a wildlife die-off in Antarctica, specifically impacting skuas – seabirds related to gulls. More than 50 skuas perished during the summers of 2023 and 2024, according to research published this week in Scientific Reports and reported by multiple sources including the University of California, Davis and ScienceDaily.

The findings stem from a study led by Erasmus MC in The Netherlands and the University of California, Davis. Researchers discovered the virus ravaging these birds, with some exhibiting severe neurological symptoms, including twisted necks, circling behavior, and falling from the sky. The most significant die-off occurred on Beak Island.

While penguins and fur seals were also examined, skuas were identified as the primary victims. This is particularly concerning given the skua’s ecological role as both predators and scavengers. Their scavenging behavior, the researchers suggest, may increase their risk of contracting and spreading the virus across the Antarctic continent.

“We knew there were animals with the infection, but this is the first study to show they died of the viral infection,” explained co-senior author Ralph Vanstreels, a wildlife veterinarian with the UC Davis One Health Institute, in a statement released by UC Davis on February 5, 2026. “It’s an important distinction in the early days of an outbreak.”

Prior to this study, H5N1 had been detected in a kelp gull and two skuas found dead in January and February 2024, but a direct causal link to the virus hadn’t been established. The current research definitively confirms H5N1 as the cause of death in a significant number of skuas.

The H5N1 strain detected in Antarctica is the same one that has caused widespread mortality in sea lions in Argentina and Chile, and has led to the culling of over 400 million poultry worldwide. It has also been identified in mammals including cows, mink, and foxes, and, in rare cases, humans.

“We let the virus slip out through our fingers when it first emerged in the poultry industry,” stated senior author Thijs Kuiken, DVM, PhD, of Erasmus University, as reported by CIDRAP. This highlights the ongoing global concern surrounding the spread and evolution of H5N1.

Researchers conducted their investigation in March 2024, shortly after the skua and penguin breeding seasons. The team surveyed wildlife across several locations in Antarctica, including the South Shetland Islands, the northern Weddell Sea, and the Antarctic Peninsula. They collected tissue samples, performed post-mortem examinations, and gathered environmental samples to understand the extent of the outbreak.

The discovery of H5N1 in Antarctic wildlife raises concerns about the potential for broader ecological impacts. Skuas play a crucial role in the Antarctic ecosystem by scavenging carcasses, helping to prevent the spread of other diseases. Their decline could disrupt this natural process.

The study emphasizes the importance of continued surveillance and monitoring of wildlife populations in Antarctica to track the spread of H5N1 and assess its potential impact on the continent’s unique ecosystem. The researchers stress the need for proactive measures to prevent further outbreaks and protect vulnerable species.

The findings underscore the global reach of H5N1 and the need for international collaboration to address this evolving threat to both animal and human health. While the current outbreak appears to be primarily affecting skuas, the potential for the virus to spread to other species, including penguins, remains a concern.

Further research is needed to understand the transmission dynamics of H5N1 in Antarctica, identify potential reservoirs of the virus, and develop effective strategies for mitigating its impact on the region’s wildlife. The researchers hope their findings will inform conservation efforts and help protect the fragile Antarctic ecosystem.