On 23rd October 2023, a short press release from the government of South Georgia and the South Sandwich Islands reported that Highly Pathogenic Avian Influenza (HPAI) – what we mostly shorten to bird flu – had been detected on the wildlife-rich islands of South Georgia.
It was the moment that this deadly form of the virus officially first arrived in the Antarctic region, completing a complex global route that has taken it from the initial outbreak in China, nearly 30 years ago, to Europe, Africa, North and South America and finally to the remote wildernesses of the Southern Ocean.
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Bird flu in Antarctica
The roll call of its impacts in Antarctica alone makes for difficult reading. Up to half of South Georgia’s breeding female southern elephant seals died between 2022 and 2024, an estimated 50,000 individuals, accounting for about 25 per cent of the global population.
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An entire colony of breeding gentoo penguins in the Falkland Islands disappeared, and while the impact on Antarctic fur seals is unknown, there are large numbers of dead males and pups.
“It likely arrived with brown skuas,” says Connor Bamford, lead author of the research into elephant seals, published in Communications Biology.
The skuas migrate all the way to the Patagonian coast to forage and brought the virus back with them after mixing with other, probably infected, birds. Bamford found that the elephant seals on South Georgia had been badly impacted in the space of just a year.
Usually, he says, the female harems are so tightly clustered on the main breeding beaches it can be difficult to find any space to walk between them.
“When we were there in 2024 doing the survey there were these huge gaps and it was just obvious that, while there were still a lot of seals, there were nowhere near as many as there should be,” adds Bamford.
The virus appears to thrive where wildlife lives in tightly knit colonies, which is how elephant seals (and other pinniped species) behave during the breeding season.
According to Jaimie Cleeland, who is the British Antarctic Survey (BAS) science manager for King Edward Point (on South Georgia), spotting the fur and elephant seals that have contracted the virus becomes relatively easy once you know what to look for. It actually damages the alveoli in the lungs of the animals.
“They get these air pockets in their lungs and it’s really sad,” she says. “You’ll see living and dead fur and elephant seals that look strange in the water because they are really buoyant. We’ve seen fur seals that are trying to dive but can’t.”
Elephant seals will normally dive to depths of up to 1,000m in search of prey – squid and fish – so it is clear just what a huge impact a virus that damages the lungs and makes diving more difficult, or even impossible, will have. The animals become unable to feed.
Though some mortality has been observed among the other iconic species on South Georgia, including gentoo and king penguins and wandering albatrosses, this has not been on anything like the same scale as the seals.
“We think that the virus is probably quite pathogenic to other species, because it has killed them elsewhere, but they’re not like seals – they don’t breathe all over each other,” says Cleeland.
How did bird flu get to Antarctica?
As already explained, the bird flu virus found its way to South Georgia via migrating brown skuas, who in turn picked it up after it had found its way down from North to South America. There have been some massive mortalities on that continent, including elephant seals at Península Valdés and South American sealions on the coast of Peru.
The origin of this outbreak was actually in Europe in 2020, when wild birds in the Netherlands began testing positive for HPAI, with subsequent discoveries in both wild birds and poultry across northern and eastern Europe.
The origins of bird flu go back much further, since it is a natural pathogen found in wild birds, with wildfowl such as ducks, geese and swans the natural reservoir. The term ‘fowl plague’ was coined to describe bird flu in poultry in Italy and other European countries in the late 19th century.
But what we now refer to as HPAI, which causes greater mortality than the natural strain, first emerged in domestic geese in China in 1996 and then jumped back into wild birds.
This latest outbreak has seen much more serious impacts on wild birds than has been previously recorded.
It was first observed in the UK in 2021. A massive outbreak among barnacle geese that breed in Svalbard and overwinter in the Solway Firth killed an estimated 30 per cent of the population in the winter of 2021–22 – more than 11,000 birds.
Bird flu in the UK
But, explains Susie Gold, senior conservation scientist for the RSPB, this hasn’t been the catastrophe you might have expected.
“Waterfowl have the ability to recover quickly from this kind of event – they have large clutches and produce offspring at a young age,” she says.
“Within a couple of years, that population was back up to where it had been before.”
That said, the virus returned last winter, and repeated outbreaks could lead to long-term declines. For seabirds, which take longer to reproduce and have fewer young, there are much greater concerns.
For example, a worrying 76 per cent of British great skuas – close relatives of the brown skuas that carried the virus to South Georgia – had been killed by the virus by 2023, reducing numbers from just over 9,000 breeding pairs to just over 2,000.
The UK itself, mostly Scotland, is home to 60 per cent of all breeding great skuas, so this loss is significant for the species as a whole.
“As a species, skuas congregate in these big clubs by freshwater pools and are obviously very susceptible to the virus. That’s the species we have seen take the biggest hit from a UK perspective,” says Gold. Their scavenging behaviour is another key reason why they have been heavily impacted.
British gannets, seabirds that breed in dense colonies, have also seen their numbers fall dramatically, with losses put at roughly a quarter nationwide.
There were fears for the future of very rare species, such as roseate terns, when an outbreak hit their only UK breeding colony of Coquet Island, off the coast of Northumberland, but a good season in 2024 has raised hopes they can survive.
The threat persists, conservationists say.
Other seabirds, such as auks, appear to have been less badly affected. Puffins’ habit of nesting in burrows may have protected them from the worst impacts, says Gold, while guillemots and razorbills seem to have escaped unscathed for reasons that aren’t yet clear.
Conservationists are watching one other group, birds of prey, very closely because they fear they may also be especially vulnerable to bird flu. In the Netherlands, for example, peregrine falcon numbers have fallen and there have been widespread declines linked to avian flu in the USA as well.
“We worry that birds of prey are going to be repeatedly hit year on year because they are scavenging and predating on infected species,” says Gold.
There is some evidence for reduced breeding success of golden and white-tailed eagles in Scotland and even a downtick in buzzard numbers, one of the UK’s most successful, widespread raptors.
Across Europe, the winter of 2025–26 took an especially great toll on common cranes. Footage from Germany shows workers in full protective gear piling dozens of carcasses on top of one another at a wetland site called Linum, near Berlin, which is heavily used by migrating cranes.
“We have never experienced anything like this, certainly not with cranes, which had not been affected by bird flu until now,” says Norbert Schneeweiss, a biologist who heads the Rinluch Species Competence Centre at the Brandenburg Environmental Agency.
More than 1,000 dead cranes were found at this one location, and one piece of research has estimated that more than 40,000 individuals, which is 10 per cent of the entire western flyway population, have died.
So far, bird flu hasn’t infected cranes in Britain but it remains to be seen whether the situation stays that way.
The winter of 2025–26 has been bad for whooper swans, with hundreds succumbing to the disease in strongholds such as the Ouse Washes.
What the future holds is unclear but, from South Georgia to the Solway Firth, conservationists are resigned to the fact that bird flu is here to stay.
Top image: king penguins with chicks in South Georgia, Antarctica. Credit: Scott Portelli/Getty Images
