Bird flu has caused catastrophic die-offs – could a wave of extinctions follow?
The southern elephant seal has become the first animal species to have its conservation status downgraded by the IUCN red list due to the H5N1 bird flu virus.
The southern elephant seal has become the first animal species to have its conservation status downgraded by the IUCN red list due to the H5N1 bird flu virus. The global authority responsible for assessing extinction risks moved the species from “least concern” to “vulnerable” after scientists documented catastrophic die-offs on the sub-Antarctic island of South Georgia.
The virus, which first began circulating in the northern hemisphere in 2021, has now spread to four of the five main southern elephant seal populations. By 2025, more than 53,000 female elephant seals had died on South Georgia, an island that is home to more than half of the global breeding population.
In some South Atlantic colonies, more than 90% of newborn pups have died, alongside about half of all adult females. The IUCN listing notes that scientists suspect the global southern elephant seal population has declined by nearly a third, and models suggest many populations will take decades to recover.
“This is a horror show for wildlife,” says Ruth Cromie, coordinator of a UN taskforce on avian influenza and wildlife. “The scale of mortality is absolutely unprecedented.”
Avian influenza is now a threat to at least 40 bird species, according to BirdLife International, a global conservation partnership. The virus has killed hundreds of thousands of animals, if not millions, since it began burning its way through the world’s wildlife.
So far, scientists have found few antibodies to the disease among surviving animals. The red list itself is updated two to three times a year, but most species are only reassessed by a panel of expert scientists once every decade or so.
Birds are the exception, as BirdLife International serves as the authority for assessing the world’s 11,000-plus bird species, reviewing hundreds of birds every year. Assessing a species’ conservation threats is a painstaking scientific and bureaucratic process, and the red list aims to reach 260,000 species by 2030.
Scientists warn that the virus poses a severe and growing threat to global biodiversity, though the full scale of its impact remains unknown. “We still need to get these things out there,” says Rob Martin, senior red list officer at BirdLife International.
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