Over the past few months, bird flu has crept up uncomfortably close to home. Public health experts have found nearly 50 known cases of the H5N1 avian influenza virus in people in the United States. Dairy farmers are approaching a full year of herd exposure to the virus. And since February 2022, more than 100 million birds on U.S. poultry farms have been lost to the pathogen or killed in efforts to stop the spread of the disease.
Meanwhile, a prevalent type of H5N1 virus, known as clade 2.3.4.4b, has also invaded ecosystems around the world, causing largely unnoticed destruction. Millions of wild animals from hundreds of species, including wild parakeets and penguins, otters and owls, ducks and dolphins, have died on every continent except Australia, some of which are being monitored by scientists. It includes some of the most pristine places in the world. Understanding the true scale of avian influenza in the wild is a matter of speculation compared to scientific estimates of its impact on domestic species.
“Wild birds often die in inconvenient locations and require human time to respond to and count them,” says Michelle Ville, a disease ecologist at the University of Melbourne. “Farmers, by contrast, usually have detailed numbers of poultry in their sheds, so it’s a matter of effort.”
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Despite the efforts, the results have been dire, with H5N1 causing a wave of deaths around the world. In South Africa, lifeguards counted the number of Cape cormorants that died from bird flu in 2021. In 2022, scientists counted 16,873 dead adult birds called sandwich terns on their breeding grounds in northwestern Europe. In early 2023, 21 giant California condors (a rare species with fewer than 600 individuals) died in Arizona and Utah. Later that year, as many as 96 percent of elephant seal pups died on a particular beach in Argentina, suggesting that the entire region had died. More than 17,000 animals may have been killed.
These elephant seals exhibited a pair of particularly alarming developments. These are evidence both that the virus can affect large numbers of mammals and that it is rapidly approaching the Antarctic region, home to some of the most amazing ecosystems and beloved animals on Earth. It became.
“When it continued south and into South America, it was a real wake-up call for us,” said Ash Bennison, a marine ecologist at the British Antarctic Survey. He said he began to worry about the threat posed by H5N1. It visited the region in early 2022, almost two years before the virus reached Antarctica.
One area of concern is South Georgia Island, a rugged wildlife island located about 900 miles from the tip of the Antarctic Peninsula and surrounded by several small islands. “People often say it’s the Alps straight out of the water,” says Mark Belchier, marine fisheries ecologist at the British Antarctic Survey and director of fisheries and environment for the South Georgia and South Sandwich Islands government. speak “As the only dry land for hundreds of miles, it is an important breeding export site.” Several species of whales feed in the rich waters, and the island is home to three species of seals, penguins and albatrosses. Each species breeds in four species and grows in clusters along the coastline. Tourists who have transportation to remote islands also flock here. More than 26,000 people, including tourists, scientists and support staff, visited South Georgia in the most recent year for which data is available.
One of them was Theo Allan. Trained as an architectural photographer, he found a lifelong home in 2019 when he turned his camera on to document an Antarctic tourism expedition. “It’s like going to Mars, where there’s no human civilization at all and nature takes its course,” Alan said. “Seeing the size of this iceberg makes me feel like an ant.”
On cruise ship excursions, he and his fellow tourists board rubber dinghies and race toward the shore, racing through icebergs that are bound to collapse at any moment. Even under the best of conditions, the job is hard. “The wind is blowing. Snowflakes and snow can hit your face,” he says. “It can get pretty intense.”
Things were even more difficult when he arrived in South Georgia in January 2024 for a visit of about two and a half months. That’s when he saw evidence that bird flu had arrived in the area.
Two skuas eating a penguin carcass. Highlights the role of the Antarctic food chain in the transmission of avian influenza.
The first confirmed case around South Georgia was found in a seabird on Bennison’s home base of Bird Island, off the western tip of the mainland. (Although humans may have brought the virus to Bird Island, scientists say there is evidence that migratory birds are the likely vector.) In mid-September, researchers I saw a sickly young southern shearwater just before it died. By early October, carcasses of black-backed gulls began to be seen. Both species are predators and scavengers, and scientists had reported that black-backed gulls were feeding on the carcasses of strange-looking shearwaters. While most of the shearwaters survived during the virus outbreak, dozens of skuas were found dead. Scientists know that avian influenza can be transmitted between species by scavenging sick animals, but it’s not clear why petrels survived the disease, Bennison said.
“They’re very strange scavengers, like elephant seals and fur seals, so they’re probably already exposed to a huge range of pathogens,” he says of petrels. “There may be certain animals with a certain biology. That may mean their immune systems are heightened, or their immune systems are more relaxed.”
But the skua was just the beginning. Bennison and colleagues also tallied deaths or deaths of gentoo penguins, wandering albatross, and fur seals on Bird Island and mainland South Georgia. Scientists wiped down as many of the carcasses as possible and sent samples back to the UK for testing, eventually confirming that many of the animals were infected with bird flu.
This area is not free from dead wildlife. “Animals are dying or dying all the time,” says Sally Ponsetto, an independent ecologist who has worked in South Georgia for decades. “That’s what South Georgia is all about. It’s all about life and death.” But after the bird flu arrived, she noticed bodies piling up faster than usual.
A king penguin waddles past the rotting carcass of an adult fur seal on South Georgia Island, part of the British Overseas Territories of South Georgia and the South Sandwich Islands in Antarctica.
Alan also noticed a difference when he arrived in January and started visiting familiar places. He expected an impact from the virus, but added: “It’s a little bit ‘numbing’ to see these animals nearly dead all along the coastline, among other living animals that would die as well.” “It was a great experience,” he says. . I don’t know how to put it into words, but it’s hard to witness. ” He could smell the difference, too. “When we approached some of these carcasses, there was a very strong odor in the air,” Alan says.
Alan was also shocked to see the survivors facing the death of their neighbors. For him, the most powerful moment of the season was watching a pod of king penguins waddle inland from the shore. One bird broke away from the flock and stood next to another penguin carcass. “The group kept walking, and then the whole group turned and looked at this one penguin standing next to the carcass,” Alan says. “It felt very human,” he said, especially remembering the darkest days of the coronavirus pandemic in India. “Loved ones don’t want to touch their relatives,” he says. “Some people did not even go to the hospital to collect the bodies.”
A flock of penguins moves away from another penguin carcass, and one of them stops waddling to stand next to the carcass.
Scientists working to understand avian influenza and its impact on wildlife are also being forced to confront the emotional realities of the dead and dying. “It’s very sad to know that very little could be done to minimize any infection or threat to these animals,” Bennison said. “All you have to do is sit back, put on your little scientist hat, and work hard to collect data that is valuable to the animals.”
This year, scientists will be able to collect even more data and process it faster. That’s because a team of researchers, including Cornell University ecologist Amandine Gamble, was in the region to directly test samples for avian influenza in South Georgia, without relying on offshore laboratories, for example. Because there is.
This testing involves not only diagnosing bird flu, but also understanding questions such as whether the animal has developed resistance to the virus. If so, the discovery raises hopes that last season’s fatal crash was an anomaly rather than a persistent threat. Ms Gamble initially felt that the scavengers might have developed a resistance, but said that was not the case for the gentoo penguins that were attacked last year in both South Georgia and the Falkland Islands near South America. .
Alan returns to the south and monitors the development of the situation. So far, scientists have hints that wildlife in South Georgia and surrounding islands is in better shape this year than last. Bennison said that as of late October, he and his colleagues had found two suspicious skua carcasses. By contrast, at the same time last year there were about 50 birds, including gentoo penguins. He added that many of the birds nesting on the island have already laid eggs and the seals have returned to establish breeding territories. But early reports this season on elephant seals in South America suggest this year’s breeding population may be much smaller than usual.
A black-browed albatross skull found in the Falkland Islands is thought to be left over from last year’s bird flu outbreak.
Amandine Gamble/Cornell University School of Veterinary Medicine
Scientists say bird flu could affect a variety of species this year, leaving the possibility of more deaths in South Georgia’s future. Moreover, southern outposts such as Antarctica that avoided bird flu last year may run out of luck in the coming months.
Still, Belkier takes hope from the fact that last year’s deaths were primarily young people, rather than adults across a wide range of age groups. “These are species that cope well with ups and downs in the environment,” he says. Their populations are structured in such a way that a breeding failure in one year will not cause the species to go extinct. But Gamble notes that she and her colleagues have seen dead adult gentoo penguins in the Falkland Islands, which could indicate long-term problems for the population.
Even in the face of more dramatic losses, Ponsetto said South Georgia has a history of resilience. Humans slaughtered countless seals and whales and introduced rats, wreaking havoc on local wildlife. Each time, with the help of humans, the species has been able to recover. “South Georgia wildlife has already been through it all,” she says.
“It’s incredibly resilient,” Ponce said. “Hopefully they’ll take care of it. That’s usually what wildlife does if we leave it alone.”
