A spate of baffling swan deaths is strongly suspected to be caused by a virulent new strain of avian flu sweeping across Britain.
Dying swans were found spinning in circles and discharging blood from their nostrils on Ulverston canal, Cumbria. Swan rescuers have taken in more than 25 dying birds in Worcestershire and nine swans were found dead in Stanley Park, Blackpool. Postmortem examinations have confirmed that six black swans and cygnets that died in Dawlish, Devon, had contracted the latest strain of bird flu, H5N8.
Brought in by wild birds migrating across Europe, the strain last caused widespread avian deaths in the winter of 2016-17. The risk to human health from the virus is very low, according to Public Health England.
Fears are growing that the virus will wipe out chickens and other poultry this winter, with outbreaks already confirmed among captive birds in Kent, Cheshire, Leicestershire, and chickens at a broiler breeding farm in Herefordshire.
The government has declared an avian influenza prevention zone across England, Scotland and Wales, requiring all bird keepers to follow strict biosecurity measures.
While the virus is particularly visible in swans and large wildfowl, other wild bird deaths confirmed this month include pink-footed geese, greylag geese, Canada geese, buzzards and curlews.
Dr Ruth Cromie, a research fellow at the Wildfowl & Wetlands Trust, said: “Wild birds are often seen as evil vectors, but they are victims of a virus which originally spread from poultry. Wild birds get used as scapegoats for poor biosecurity and people moving chickens around the globe.”
She said avian flu, like all influenza viruses, regularly mutates, and there are either genetic or environmental factors making it particularly pathogenic this year. The virus disrupts the nervous system and can cause neurological symptoms in birds, such as head-twitching, stumbling and swimming in circles.
Cromie added: “We can be sure it is causing high levels of mortality this year.”
Caroline Sim, of Flying Free, a volunteer operation to protect and rescue swans in Ulverston, said she had never seen such strange symptoms in the family of 10 swans there that died of bird flu.
“Many of them started to spin on their axis in one direction. It was terrible to see. Some of them were discharging from their nostrils and some of it was bloody,” she said. The dead birds were collected by officials from the Department for Environment, Food and Rural Affairs (Defra) to be tested.
David Cash, of Worcester Swan Rescue, said about 25 swans had died. “The swans were looking lethargic and not wanting food, and doing a lot of coughing – it’s similar to the symptoms of Covid.”
The government’s prevention zone obliges all bird keepers to take measures to discourage mixing between captive and wild birds, such as feeding and watering their birds in enclosed areas, and removing wild bird food sources from around captive birds.
Experts noticed an unusually high level of avian flu in Russia during the summer, and this has been spread across Europe by wild species, such as swans and geese, during their westward migration for the winter.
Christine Middlemiss, the UK chief veterinary officer, repeated the Food Standards Agency advice that bird flu poses a very low food safety risk for consumers.
She added: “Whether you keep just a few birds or thousands, you are now legally required to meet enhanced biosecurity requirements and this is in your interests to do, to protect your birds from this highly infectious disease.”
Cromie said that while improving biosecurity was the best short-term solution, the authorities should be looking at how these viruses originate in and are amplified by industrial meat production. Britain slaughters more than 1 billion chickens every year.
She said: “We should not be looking to put every chicken in a house, but asking: do we really need to have that many chickens? We’re creating these nutty industrialised production systems that create a variety of health problems.”
This article was first published by The Guardian on 27 November 2020. Lead Image: Swan rescuers have taken in more than 25 dying birds in Worcestershire and nine swans were found dead in Stanley Park, Blackpool. Photograph: Dave Rushen/Sopa Images/Rex/Shutterstock.
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