The UK's largest avian flu outbreak has left millions of birds dead – and scientists extremely concerned

2022 has seen a deadly and highly pathogenic new strain of H5N1 bird flu make a cataclysmic impact on captive and wild bird populations. Conservationists and scientists are counting the cost.

Northern gannets and other seabirds fill the sky around St Kilda, off the coast of northwest Scotland. This breeding habitat – which is also a key tourist destination – is one of the sites hit hard by the spread of H5N1 avian influenza, in an outbreak that began in 2021 and shows no sign of ebbing.

Photograph by Jim Richardson / National Geographic Image Collection
By Lauren Jarvis
Published 27 Sept 2022, 13:54 BST

LIKE PTEROSAURS guarding the gateway to a Jurassic lost world, seabirds circle the soaring sea stacks of St Kilda as my boat docks on the archipelago’s rugged and remote isle of Hirta in Scotland’s Outer Hebrides. I’m here on one of the bracing boat trips which carry day-trippers more than 40 miles across the turbulent North Atlantic Ocean to the UK’s only dual UNESCO World Heritage Site, preserved for both its cultural and natural heritage. Stone houses, cleits (storage huts) and ruins which scatter the windswept landscape are testament to 5,000 years of human settlement, while the archipelago’s extraordinary marine ecology, geographical position and climate makes it a magnet for birdlife. The breeding colonies here are the most significant in the North Atlantic and the largest in Europe, supporting over one million seabirds, including the world’s largest colony of Atlantic puffins.

My journey to the end of the world came shortly before COVID-19 slammed the gates on such magical realms. Now, with the darkest shadow of the pandemic possibly behind us, another deadly plague has darkened Scotland’s shores, and spread through the British Isles, leaving a catastrophe in its wake. 

Eclipsed by headlines focussing on Ukraine, spiralling energy bills and the government leadership contest, an ecological disaster has been unfolding. A new, highly pathogenic form of avian influenza or ‘bird flu’, known as H5N1, has been ravaging poultry flocks and wild bird populations across the northern hemisphere, leaving UK conservationists and scientists alarmed and calling for urgent, decisive government action.

A dead gannet, believed to be a victim of avian flu, lies on a Scottish beach, ...

A dead gannet, believed to be a victim of avian flu, lies on a Scottish beach, June 2022.  Scenes like this have been reported across the U.K. as wild and domestic bird populations reel from the country's worst ever outbreak of avian flu.

Photograph by Lorne Gill / NatureScot

“Very, very scary”

“I’m a scientist by training, and like all scientists, I’m used to taking a measured approach and don’t take the language I use lightly,” says Jeff Knott, Director of Policy for the UK’s largest nature conservation charity, the RSPB. “But the severity of the situation and scale of the impact is unprecedented and very, very scary. It’s a huge crisis that could turn into a catastrophe unless we get ahead of it.”

First recorded in geese farms in Southern China’s Guangdong province in 1996, H5N1 spread through Asia’s poultry units and spilled over to infect populations of wild birds including ducks, geese and swans, which carried the virus to Europe on their migrations. The province is not only home to some of the country’s largest industrial livestock and poultry farms, intensively housing millions of animals, but is also one of China’s most important wintering sites for migratory birds.

In 2012, a study identified Southern China with its intensive farms, smallholdings, wildlife and wet markets as having ‘a unique ecological system optimal for influenza viral emergence’, and warned that avian flu viruses would be ‘a continuous threat to both animal and human health.’ The region’s wet markets (including live animal markets and slaughterhouses) enable influenza A viruses to overcome geographic barriers by connecting farms, backyards and wildlife subsystems, bringing large numbers of animals into close contact.

An RSPB worker in PPE examines a dead skua suspected of succumbing to avian flu.

An RSPB worker in PPE examines a dead skua suspected of succumbing to avian flu. 

Photograph by Ashley Cooper
Dead roseate terns are pictured with dead chicks, Coquet Island RSPB reserve, off the Northumberland Coast.

Dead roseate terns are pictured with dead chicks, Coquet Island RSPB reserve, off the Northumberland Coast.  

Photograph by RSPB Images
The northern gannet is the largest species of seabird in the north Atlantic, with the coasts ...

The northern gannet is the largest species of seabird in the north Atlantic, with the coasts of Scotland an important breeding habitat. Approximately 220,000 pairs of the bird nest on UK shores – approximately half the global population.  

Photograph by Ashley Cooper / RSPB Images

Early outbreaks of H5N1 impacted species during the autumn and winter months, dying out with the arrival of warmer weather. A new strain of H5N1, which first emerged in 2014, appears to now be spreading more easily among domestic and wild bird populations, and outbreaks are persisting year-round – suggesting the virus may now be endemic in wild birds. Indicators of the pending tragedy included the demise of 300 demoiselle cranes in India in November 2021, 5,000 common cranes succumbing to H5N1 in Israel in December, and more than 2,000 near-threatened Dalmatian pelicans dying in Greece. Wild birds have also been severely impacted across North America.

“So far, we know this variant is highly contagious and has infected more than 60 different bird species, including birds of prey, and it has also jumped to mammals including foxes and otters,” says the RSPB’s Jeff Knott. The virus is spread by the movement of infected birds and from bird-to-bird through contact with contaminated body fluids and faeces. “But there is still so much we don’t know about the virus,” says Knott. “We are in previously uncharted territory.”

Globally, the World Health Organisation (WHO) reports that from January 2003 to 25 August 2022, there have been 864 cases of human infection with H5N1 across 18 countries. Of these, 456 were fatal, a case fatality rate of 53%. The deaths have been linked to exposure with infected poultry or contaminated environments, but the advice on the WHO website also states: ‘If the H5N1 virus were to change and become easily transmissible from person to person, while retaining its capacity to cause severe disease, the consequences for public health could be very serious.'

As the human population grows and we continue to lose forests and biodiversity, incidents of zoonotic diseases are increasing. COVID-19, which a WHO investigation found ‘likely to very likely’ to have jumped from bats through a host animal to people, is a recent example of the devastation they can wreak.

The first human H5 infection in the UK was recorded in January 2022. “Currently there is no evidence that this strain detected in the UK can spread from person to person,” says Professor Isabel Oliver, Chief Scientific Officer at the UK Health Security Agency (UKHSA), “but we know that viruses evolve all the time and we continue to monitor the situation closely.” The Food Standards Agency (FSA) has confirmed that avian influenza poses a low food safety risk for consumers, with safely cooked poultry, poultry products and eggs safe to eat.

In an attempt to stop infections spreading from and between poultry farms, the government introduced a nationwide Avian Influenza Prevention Zone (AIPZ) on 3 November 2021, detailing strict biosecurity measures for all bird keepers, including disinfecting clothing, footwear and equipment before and after contact with captive birds, minimising movement and contact with wild birds, and maintaining sheds and feed stores to prevent contamination with other wildlife.

While the nationwide AIPZ was lifted on 16th August 2022, regional restrictions are still in place, and on 31st August, an AIPZ was declared across Devon, Somerset and Cornwall (including the Isles of Scilly), following infections being detected in captive and wild birds across the region.

Chickens are pictured at a poultry farm outside Shanghai in 2013, as a highly infectious novel strain of bird flu – H7N9 – was emerging in China and had made the jump to humans. The strain was particularly insidious as it caused few symptoms in birds but severe disease in many of the people it infected. Since 2013 over 1,500 people have been infected with H7N9 over six epidemics, with a fatality rate of 39%. Though typically contracted by poultry workers, rare human-to-human transmission of the strain makes it of particular concern as a cause of a potential pandemic. 

Photograph by Imaginechina Limited / Alamy

“The Notifiable Avian Disease Control Strategy for Great Britain outlines the swift and humane culling of birds on infected premises, coupled with good biosecurity, to prevent the spread of the disease,” says Professor Ian Brown, Head of Virology Department at the Animal and Plant Health Agency (APHA). Since the start of the current outbreak, 2.8 million kept birds (poultry and other captive birds) have either been culled or have died of the disease in the UK. In North America, the figure rises to 40,568,641. “In both captive and wild birds, the scale of this avian flu outbreak is unprecedented,” confirms Brown. “And at present, it is too early to say how many years this virus will continue to circulate.”

The H5N1 strain was first detected in the UK’s wild bird population in July 2021 on the Scottish islands of St Kilda and Shetland, when a small number of great skuas were confirmed to have died from avian flu, then H5N1 killed more than one-third of the Svalbard barnacle geese which winter around the Solway estuary. This spring brought significant deaths in eider flocks, and tens of thousands of other seabirds and chicks have now been found dead, likely equating to hundreds of thousands of lost birds.

Scotland has 60% of the world’s population of breeding great skuas and 46% of breeding gannets. On Bass Rock in the Firth of Forth, which supports 150,000 northern gannets – the world's largest breeding colony – thousands of birds have died, while tern colonies in England, Europe, the Faroe Islands and Canada have also been badly hit. Now widespread across the length and breadth of the UK, H5N1 has been found in a broad range of species including pink-footed geese, buzzards, mute swans, a red kite and a sea eagle, but it’s among breeding seabirds that the most significant mortality events are occurring.

“Great skua, gannets and guillemot have been hardest hit. Numbers of dead great skua, gannets and guillemot are now in the thousands with declines of up to 85% at great skua colonies and up to 25% at gannet colonies,” says Emma Philip, Marine Ecosystems Manager at NatureScot, which advises the Scottish government on the country’s natural heritage. “Manx shearwaters, great black-backed gulls, herring gulls, Arctic terns, Sandwich terns, kittiwakes, razorbills and puffins have also tested positive”.

To try and contain the outbreak, NatureScot advised the suspension of public landings and tours of some of Scotland’s birding hotspots including St Kilda, Mousa in Shetland, the Isle of Noss and the Isle of May during the summer months, leaving visitors to view the colonies from a safe distance without going ashore. NatureScot also issued advice to managers of seabird colonies and the British Trust for Ornithology (BTO) to suspend bird ringing and research activities. As the birds leave the colonies to head out to sea once more, some island access is being restored.

“The avian flu crisis has been rapidly evolving and deteriorating,” says Philip. “Tragically, this disease could be with us for some time to come, with early evidence confirming avian flu has moved into our urban gull and raptor populations, developments NatureScot and our partners are monitoring closely.”

Like COVID-19, the persistence of the virus in the environment, and birds’ ability to develop resilience, will be key factors determining long-term population impacts. 

“All seabirds are relatively long lived, take years to reach reproductive age and invest heavily in a single brood each year,” explains Philip. “This means that significant impacts on the adult population, in combination with other pressures, can result in a slow population recovery.”

Right: Lying in nests composed of discarded plastic netting, northern gannets lie dead from an outbreak of bird flu at Herma Ness on Unst, Shetland. Cliffs such as those at Troup Head off the coast of Aberdeenshire are critical nesting grounds, where the birds gather in high densities of tens of thousands – and where pathogens can decimate populations. Many seabirds take a long time to reach maturity, meaning the deaths of breeding-age birds represent a big hit to species numbers, some of which were already dwindling.  

Photograph by Lorne Gill / NatureScot, left; Ashley Cooper / Alamy, right

“This disease could be with us for some time to come, with early evidence confirming avian flu has moved into our urban gull and raptor populations.”

Emma Philip, NatureScot

Extinction threat

For the great skua (also known as the bonxie) which has been severely impacted by H5N1, conservationists fear these factors could lead to the global extinction of the species, which is already battling tough odds to survive. The UK’s only roseate tern breeding colony on Northumberland’s Coquet Island – an internationally recognised wildlife sanctuary and home to an estimated 82,000 seabirds – is also at risk.

“We haven’t seen a species go globally extinct in Europe since the last two great auks were hunted down off the coast of Iceland in 1844,” says the RSPB’s Jeff Knott. “Seabird populations are already extremely poor in heart, so for some like the great skua, bird flu could be the straw that breaks the camel’s back: we cannot let the species go extinct on our watch.”

A RSPB study found that there are over 600 million fewer birds in Europe today than there were 40 years ago, and the continent has lost one-fifth of its birds since 1980. While Britain, Ireland and their associated islands are home to an estimated eight million breeding seabirds from 25 different species, they are one of the most threatened bird groups, under pressure from marine development, overfishing, entanglement in fishing gear, predation by invasive species, pollution and climate change. Their tight-knit breeding colonies, where thousands of birds live feather-to-feather, are also prime locations for super-spreader events.

For those working in conservation, seeing thousands of birds succumb to the disease is devastating. While some infected birds can be asymptomatic, others display a distressing range of clinical signs, including a lack of coordination and balance, head and body tremors, watery eyes, drooping wings and twisting of the head or neck. They can also exhibit difficulty breathing and severe haemorrhaging. Scientists and members of the public have been brought to tears at the sight of dead birds strewn across beaches or floating lifeless at sea.

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NatureScot has set up a new task force to coordinate a national response to the avian influenza crisis, bringing together government, conservation organisations, local authorities and the research community. Key priorities will include tackling the current outbreak, planning an effective response for future outbreaks and variants, and taking action to help protect and restore bird populations and improve their resilience. The agency is also forming a sub-group of its Scientific Advisory Committee to provide further support and expertise on surveillance, monitoring and research. The RSPB is calling on DEFRA to set up a similar task force to coordinate a unified response across the UK’s four countries to mitigate the impact on wild birds. To date, the agency has set out a Mitigation Strategy for Avian Influenza in Wild Birds in England and Wales, with advice for land managers, ornithologists and conservation organisations.

“The UK government’s response has largely been aimed at containing the disease in poultry,” says the RSPB’s Knott. “We urgently need a national task force to implement coordinated monitoring, testing, reporting and communications to understand the spread of avian flu in wild birds, and the government also needs to address the other very real threats to our seabirds.” 

The planet’s changing weather patterns and climate change are already impacting bird migrations, which could potentially lead to an increase in the spread of avian influenza between species that haven’t come into contact before. Additionally, extreme natural events can also trigger abnormal population movements. Once again, human activity, including the non-ethical treatment of animals and intensive farming practices which keep animals in over-crowded unnatural conditions, have come under the spotlight, as another zoonotic disease takes its toll around the world.

Coquet Island, an RSPB reserve off the coast of Northumberland, is an important nesting colony for seabirds such as terns and puffins. 

Photograph by Ashley Cooper / RSPB Images

“There's not much doubt that this disease evolved in domestic poultry in Asia,” says Dr. Mark Avery, one of the founders of conservation group Wild Justice. “All birds are now at risk and this year's massive spread to seabirds and a wider range of wild birds shows that the threat has stepped up a notch.”

Wild Justice and the RSPB have also expressed concerns about the unknown consequences of the game bird release currently happening across the UK, for the annual autumn shooting season. It’s estimated that the number of game birds kept in the UK each August is equivalent to half the biomass of all wild birds in Britain.

“It's surely unwise to release tens of millions of captive-bred birds into the countryside at this time,” says Avery. “The releases might carry avian flu but it’s more likely they'll contract avian flu and act as a reservoir for the disease, perhaps exacerbating the spread to truly wild birds, or to commercial poultry flocks. It's not a risk worth taking for recreational shooting.”

The game bird industry is already feeling the impact of avian influenza. H5N1 cases in the Vendée and Loire-Atlantique regions of France – where around half of the 50-60 million partridges and pheasants, reared to be shot, are sourced for the UK market – have resulted in restrictions on the movement of live birds and eggs, and the cancellation of some shoots. But with captive-reared game bird and wild fowl releases already in progress, many shoots set to go ahead, and the virus identified in both wild and farmed pheasants in the UK, the RSPB is calling for an immediate moratorium on the practice.

Grouse shooting on the Scottish moors. Game shooting is a major industry across the UK, with millions of birds bred specifically for the sport. Campaigners are arguing the release of birds such as pheasant will provide a reservoir for the virus to spread, and potentially increase human contact with infected birds. 

Photograph by Jim Richardson National Geographic Image Collection

A grouse pictured in the Scottish highlands. The red grouse shooting season begins on the so-called 'glorious 12th' of August. The pheasant shooting season begins on 1st October. 

Photograph by Jim Richardson / National Geographic Image Collection

Glynn Evans, Head of Game and Gundogs at The British Association for Shooting and Conservation (BASC) has responded, saying: “The government’s mitigation strategy indicates shooting activities represent a very low risk of dispersing avian influenza, so to call for a complete moratorium while providing no evidence, nor proportionality, is seriously flawed and shows a fundamental lack of understanding of the science.” Game bird release is not permitted within disease prevention zones, and BASC says the shooting community is following the Government’s guidelines to play its part in tackling the disease. But while the risk assessment considers the likelihood of spreading the disease by shooting as low, it states it does not take into account “the risk posed [by H4N1] to the wider wild bird population through the active release of gamebirds.”

Northern gannets fly off Bass Rock, in Scotland's Firth of Forth – an important breeding ground for the birds. 

Photograph by Lorne Gill / NatureScot

With the industry estimated to be worth £2 billion and providing over 70,000 jobs, the BASC is pushing for the game shoots to go ahead. But with so much still to learn about H5N1, millions of domestic birds already culled, and some wild bird species pushed to the brink by the virus, conservationists are advising governments to listen to their calls of alarm.

Birds swoop high over Scottish cliffs following the flightpaths of their prehistoric ancestors for now, but protecting them from a similar fate will take immediate and decisive action. “We are facing a nature and climate emergency, and an emergency demands an urgent response,” says Jeff Knott of the RSPB. “We cannot allow our amazing seabird cities and the countryside’s dawn chorus to fall silent.”

If you come across a bird you suspect is infected with avian flu, do not touch it. Read guidance on what to do here

Lauren Jarvis is a freelance travel and conservation journalist based in London. Follow her on Instagram


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