Editor’s note: This article was originally published on 12 July 2022. On 23 May 2023, Brazil – the world’s biggest exporter of chicken meat – announced an animal health emergency that will last 180 days. This week the World Organisation for Animal Health also said that governments should consider vaccinating poultry against bird flu, to prevent a new pandemic.
Political paralysis, looming recession and climate change: dark metaphorical clouds are hanging over Britain – and now dead birds are falling from the sky. Take a walk along a beach in Scotland or down the east coast of England this summer and you are likely to find the bodies of sick seabirds washed up on the shore. In Brighton last weekend a seagull dropped dead mid-flight.
If this feels particularly apocalyptic, even by 2022’s standards, then it should. “The last nine months have been unprecedented,” an RSPB officer said. “We have never seen anything like this before.”
The deaths are the result of a new variant of H5N1, a strain of highly pathogenic avian influenza, or “bird flu”. Low-pathogenic bird flu circulates naturally and causes no signs of disease in wild waterbirds, but the crowded conditions of intensive poultry farms can cause the virus to mutate into a deadly form. The origins of this particular strain have been traced to a farm in the Guangdong region of China in 1996. Since then, it has spilled over to wild birds and travelled westwards to Europe, Africa and, more recently, North America, via the movement of poultry and wild migration.
Desperate measures, including mass poultry culls, have been used for decades to try to contain the disease, but the recent variant is now killing wild birds at alarming speed. At first it seemed to be limited to small outbreaks during winter, mainly in ducks, geese and swans, explains the RSPB’s Martin Fowlie. Then, this past winter, the spread didn’t stop with the spring as experts had hoped. Birds from previously uninfected species are now dying in vast quantities – from gannets to roseate terns to great skuas (of which the UK is home to half the global population).
The exact wild death toll is hard to determine. This is partly due to the lack of a joined-up system for monitoring and recording the deaths, explains James Pearce-Higgins from the British Trust for Ornithology. But Fowlie estimates Britain’s current total figure for the year at “tens of thousands, possibly hundreds of thousands” and conservation groups have been doing what they can, including launching fundraising appeals to support survey work.
Seabirds breeding in closely packed colonies are proving especially vulnerable. Estimates put declines for some species as high as 85 per cent on some Scottish islands. In one particularly heart-wrenching video an infected gannet is seen in torturous spasms; birds often suffer fits before death. On Coquet Island, Northumberland, all the chicks from 1,964 sandwich tern nests died. Birds of prey that eat dead birds are also at high risk.
Nor is it just the UK’s seabirds that are impacted. The disease is killing at an unprecedented scale, from peregrine falcons in the Netherlands to cranes in Israel. Nearly 400,000 wild bird deaths from the disease have been counted by the World Organisation for Animal Health in the last year alone (a conservative estimate). According to Thijs Kuiken, a professor of comparative pathology at the Erasmus University medical centre in Rotterdam, this year’s outbreak “has affected both more poultry farms and more wild birds in Europe than any before it”.
For some species the consequences could be dire. Birds returning from the arctic this autumn, such as dunlins and oystercatchers, could become infected in their hundreds of thousands. Furthermore, many seabirds are long-lived and only produce one or two chicks a year, so the deaths of large numbers of adults will lead to precipitous declines. For species, such as roseate terns, that are already declining or have small populations, local extinction is an increasing possibility, Kuiken warns.
Stopping the devastation will not be easy. Vaccination of wild birds is almost impossible due to the lack of a vaccine that can be delivered orally (and so easily distributed) and the vast numbers of species (and their food sources) in question. More support for monitoring the scale of the deaths is therefore essential to understanding the virus’s potential impact and assessing what can be done. Expert groups from across relevant industries, science and conservation need to be formed to better model how the disease moves between species, says Fowlie, “but we’re not seeing the government doing that, and with [parliamentary] recess it’s likely nothing will happen over the summer”.
Increased protection for breeding sites, as well as measures to guard against overfishing and poorly placed wind turbines, could help seabird populations increase their chances of recovering from the disease, conservation experts stress. And such calls to protect habitats can’t come loudly enough in light of a new report from the UK Environment Agency warning that 15 per cent per cent of native flora and fauna species now face extinction, including a quarter of mammals.
Avian flu specifically, however, will probably also need to be addressed at its source: poultry farms. The EU’s non-vaccination policy for poultry needs to be dropped, Kuiken argues, and longer term plans should look at high-intensity farming. The emergence and spread of new variants is correlated to the density of birds in farms, so “to decrease the chance of new variants we should have smaller numbers”. “It’s a man-made problem”, he says, and “just one of many arguments in favour of system change” in the agricultural sector, alongside land protection and the need to reduce carbon emissions.
If we don’t take action soon, then the virus’s next deadly stop could be even closer to home. While H5N1 crossing over into humans has so far been rare, that could change, Kuiken warns. Other carnivore species, including otters, polecats and seals, have died from the disease causing infection of the brain. Even if not very virulent, a sufficiently transmissible variant in people could cause a huge problem: in 1918 Spanish influenza, which derived from birds, killed between 20 and 50 million people.
Could it be the next Covid-19? “Yes,” Kuiken says. “We’re knowingly risking our own lives by allowing this kind of system to continue as it is.”
[See also: Saving Our Wild Isles is David Attenborough’s most political show yet]