BEHIND THE HEADLINES
Bird flu devastation
A highly pathogenic strain of bird flu has killed thousands of seabirds and waterfowl in the UK this year and decimated colonies at the height of the breeding season. Mark Rowe asks, what are the long-term impacts, and can any lessons be learnt for welfare within the food industry?
WHAT IS BIRD FLU?
The latest wave of avian flu descends from the H5N1 strain of avian influenza that originally arrived in the UK in 2005/06, most likely from dense poultry and geese farms in China and South East Asia.
“Most of the time this has behaved like a normal, natural avian flu, coming and going, bad some years then dropping to a low level,” says Martin Fowlie of the RSPB. “But it’s fair to say this is the worst-ever outbreak in the UK. We have been in unchartered territory with the disease this year and its effects on wild birds. It has mutated into a really nasty strain.”
The latest version emerged in the summer of 2021, when sick and dead great skuas were found in Shetland, Orkney, St Kilda and the Flannan Isles. Other seabirds and waterbirds were affected over the 2021/2022 winter, but this spring the virus surged again, hitting colonies as they returned from the sea to breed.
Birds can be infected with the virus through contact with saliva, nasal secretions or faeces. Wild birds, including waterfowl, are often more resistant to avian influenza than domestic birds, and can carry and transmit the virus without showing signs of disease. Movements of farmed poultry around and between countries is another vector.
WHAT HAPPENS NEXT?
NatureScot, the Scottish government environmental agency, has warned the virus is likely to remain in circulation “for some time”.
“The problem,” says Fowlie, “is that this deadly strain of avian flu has hit extremely vulnerable populations that are already under great pressure. Bird flu is just one more thing our seabirds have to deal with. Our seabirds are already under massive pressure from human impacts, including climate change, lack of prey fish, deaths through entanglement in fishing gear and development pressure.”
In the absence of effective monitoring or measures, the RSPB and others are crossing their fingers that avian flu recedes over the winter. “The concern is if it comes back again to already depleted populations,” explains Fowlie. “We are hearing talk of potential extinction for some species, such as the great skua.”
“We are hearing talk of potential extinction for some species, such as the great skua”
Martin Fowlie, RSPB media manager
DO IMPORTED BIRDS AND POULTRY PRODUCTS PLAY A PART IN THE DISEASE?
Not only is avian flu likely to have originated in Asian poultry farms and arrived via processed and air-freighted meat but current game-hunting practices may compound the problem.
Ornithologists have expressed disquiet at the widespread import of game birds from France for the shooting industry, because the major breeding sites for pheasants and partridges in the Vendée and Loire-Atlantique have been affected by avian flu.
Restrictions were in place over the summer and the release of game birds in restricted zones in the UK was prohibited.
IS IT JUST AFFECTING WILD BIRDS?
No. Several reports of H5N1 have been identified over the summer at poultry farms across the UK. Protection, exclusion and surveillance zones were set up in affected areas. One consequence was a legal requirement to keep poultry indoors, leading to all eggs no longer being classified as free range.
HOW MANY WILD BIRDS DIED?
The true number may not be known, as many birds die at sea or are washed away. There is no cure or treatment for bird flu and almost all infected birds die. “We are looking at hundreds of thousands of birds,” says Martin Fowlie.
Britain’s seabird populations are of global significance; the UK hosts 56% of the world’s northern gannet population, while Scotland has 46% of the world’s northern gannets and 60% of the world’s great skuas. Both these species are amber listed in Birds of Conservation Concern.
As of mid-July, 508 positive cases of the strain – among 28 species over 139 locations – had been identified in Scotland, though the true number will be far higher.
The bird flu virus survives after it has killed its host and there is concern that it could spread widely in white-tailed and golden eagles when they scavenge or kill dead or infected birds.
THE UK HOSTS
56%
OF THE WORLD’S NORTHERN GANNETS
● Some great skua colonies have lost up to 80% of their populations. The National Trust for Scotland (NTS), which manages the UNESCO World Heritage Site of St Kilda, said a significant proportion of the islands’ great skuas have died. Dead birds have been found on Papa Westray, Shetland and elsewhere.
● Guillemots have also been hit, with numbers of dead chicks found below clifftop breeding sites.
● The key roseate tern population on Coquet Island in Northumbria has also been devastated.
● Black-headed gulls have been found dead from the disease in Suffolk.
SCOTLAND HAS
60%
OF THE WORLD’S GREAT SKUAS
● Ornithologists estimate 3,000–4,000 barnacle geese died over the 2021/22 winter around the Solway Firth, a third of the regional population.
● More than 100 gannets have died on St Kilda. At Bass Rock in the Firth of Forth, the world’s largest gannetry has also been hit, with more than 150 dead birds discovered along the coastline.
● Curiously, so far puffins, kittiwakes and fulmars have been relatively unscathed. The RSPB is keen to establish if this is down to chance or something more significant.
● Defra and the UK Health Security Agnecy say the risk of avian flu in garden bird species is very low.
WHAT CAN BE DONE TO MINIMISE FUTURE OUTBREAKS?
Nothing can be done to save individual birds infected. But the RSPB believes that to deal with future HPAI (highly pathogenic avian infuenza) outbreaks in wild birds, improved surveillance, testing and carcass collecting is essential, and that an effective plan should be put in place for biosecurity measures and to minimise disturbance. “Scotland and Wales have put some measures in place, but in England it is glaringly absent,” says Fowlie. “When bird flu first arrived there was a task force – a collaboration of virologists, vets, ecologists – that was important and so useful. For whatever reason, that has not happened this time. We need to be more joined up in how we deal with our marine environment. “We need to tackle invasive species, such as rats and mice in colonies, reinforce and effectively police our marine protected areas, we need to be cleverer about where we put offshore wind farms,” adds Fowlie. “Monitoring of trends and populations is needed – funding for data has dried up.”
WHAT SHOULD I DO IF I FIND A DEAD BIRD?
The risk of contracting the disease from a wild bird is very low, but you are advised not to touch any sick or dead birds, their droppings, or any water nearby, as the virus survives long after it has killed its host.
Should you find any dead swans, ducks, geese, gulls, seabirds, birds of prey, or five or more of any other species in one place, report them to Defra by calling 03459 335577. In Northern Ireland, call DAERA on 0300 200 7840.