Since 2021, as COVID-19 spread among the world’s humans, birds have been ravaged by a parallel pandemic that scientists have called “unprecedented and catastrophic”. The particularly virulent strain of H5N1, or avian influenza, has likely killed millions of wild birds: pelicans, cormorants, terns, gannets, skuas and other birds from Scotland to Tierra del Fuego. In the United States, 58 million farmed chickens and turkeys have been slaughtered to prevent further spread.
The pathogen has periodically emerged in crowded poultry farms, but this is the first time it’s become established in wildlife, allowing it to survive year-round. (Mammals can catch the disease from birds but, so far, cannot infect each other; nonetheless, the virus has killed sea lions, seals, foxes, and a small number of people.)
Some gannets seem to be developing immunity to this strain of the virus (the irises of those that survive the flu turn from blue to black). But there have been huge mass die-offs of wild birds—13,000 barnacle geese in Scotland, 100,000 boobies in Peru.
And those birds that catch the virus but are less affected are spreading it across oceans and continents. This spring, skuas brought it from South America to South Georgia—within cooee of the Antarctic Peninsula.
That’s very bad news for New Zealand’s poultry and rare birds, says the chief veterinary officer at the Ministry for Primary Industries, Mary van Andel. If this strain establishes in Antarctica, seabirds could bring it to New Zealand’s subantarctic islands—and the mainland.
“Until this change in the disease, our geographical isolation had protected us. But that doesn’t appear to be something that we can count on any more.”
We can’t stop it, she says. “But we can work together to make it less bad.”
Various ministries are hatching plans and gathering advice from overseas, van Andel says. In the USA, officials are trialling a vaccine to protect endangered California condors; it’s hoped this could help some of our rarest taonga.
It’s hard to say which of our birds could be most at risk, van Andel says—this virus is too new and unpredictable. “But what we’re hearing from our scientific community and from international experts is that the effect on biodiversity could be extremely high.”