A polar bear has been killed by bird flu as the highly contagious H5N1 virus spreads into the most remote parts of the planet.
The death was confirmed in December by the Alaska Department of Environmental Conservation. “This is the first polar bear case reported, for anywhere,” Dr Bob Gerlach, Alaska’s state veterinarian, told the Alaska Beacon.
It was found near Utqiagvik, one of the northernmost communities in Alaska, two years after this latest strain was detected in North America. Gerlach said it was likely the bear was scavenging on the carcasses of infected birds.
Polar bears are listed as “vulnerable” on the International Union for Conservation of Nature (IUCN) red list of endangered species, mainly due to the loss of sea ice.
It is possible that more bears have died unnoticed as they tend to live in remote places with few people, said Gerlach. “You’re really dependent on the public that’s out there, or the wildlife biologists that are doing surveillance,” he said.
The current outbreak of the highly infectious variant of H5N1 – which started in 2021 – is estimated to have killed millions of wild birds. Globally, thousands of mammals have also died of the virus, including black bears and brown bears. Bald eagles, foxes and kittiwakes are among the species to have died of the virus in Alaska in recent months.
“It’s been in Antarctica and now it’s in the high Arctic in mammals – it’s horrifying,” Diana Bell, emeritus professor of conservation biology at the University of East Anglia, told the Guardian.
“And yet I’m not surprised – in the last couple of years the list of mammals killed has become enormous. It’s killed such a wide range of predatory and scavenging mammals now, this isn’t just a poultry disease.
“When it hits a large, charismatic species like a polar bear, people suddenly sit up and listen – or at least I hope they will. We’ve already got a pandemic in biodiversity and it’s called H5N1 because it’s killed so many birds and mammals.”
The first known cases of H5N1 were detected in the Antarctic region in October among brown skua on Bird Island, off South Georgia. Two months later, hundreds of elephant seals were found dead. There have also been increased deaths of fur seals, kelp gulls and brown skua at several other sites.
Scientists have warned that the highly contagious virus could bring “one of the largest ecological disasters of modern times” if it reaches the remote penguin populations.
The virus is continuing further south in the Antarctic region. A Brown skua is suspected to have died from it in Heroína Island, on the tip of the Antarctic Peninsula.
It is currently awaiting further testing, according to the latest update on the SCAR (Scientific Committee on Antarctic Research) website. “It doesn’t bode well,” said Dr Meagan Dewar, leader of the SCAR Antarctic Wildlife Health Network.
Dewar was one of the authors of a risk assessment which found many Antarctic animals were threatened, including gulls, skuas, fur seals and sea lions.
She said: “The analysis indicated a heightened risk that HPAI [highly pathogenic avian influenza] would present in Antarctic species in 2023 or 2024 in the Antarctic Peninsula region and that is exactly what we are seeing.”
Ecosystems in polar regions are particularly vulnerable to bird flu because they contain many animals found nowhere else in the world which have never been exposed to similar viruses. They are also among the places most affected by climate breakdown.
