A deadly and contagious viral disease known as avian influenza (or bird flu) is infecting wild birds around the UK, particularly affecting seabird populations.
One of the worst outbreaks of avian influenza ever recorded in the UK is currently sweeping through wild bird populations, with huge numbers of birds suffering and dying from the disease. The bird flu causing these birds to die is a highly mutable and deadly new form that originated in poultry farming.
Avian influenza, commonly known as bird flu, is a contagious viral disease affecting the respiratory, digestive and/or nervous systems of many species of birds. There are many different forms of the disease, and while it mainly affects birds, it can on occasion also affect humans and other mammals. There are many different symptoms, including neurological issues such as loss of coordination, moving in circles, and body or head trembling.
A dead gannet on Shetland.
Bird flu is passed from animal to animal through contact with infected saliva, nasal secretions or faeces. Wild birds, including waterfowl, are often more resistant to bird flu than domestic birds and can carry and transmit the virus without showing evidence of disease, so when they migrate they can spread the virus even further. Moving poultry such as chickens around and between countries is also known to be a major cause of the spread the virus.
There are many forms of the virus, not all of them fatal, but the strain known as highly pathogenic avian influenza (HPAI) is the most serious type of bird flu and is often fatal in birds.
A huge number of species have been affected by bird flu this year, including many species of wildfowl, seabirds such as gannets and fulmars, gulls, birds of prey such as sea eagles, buzzards, kestrels, peregrines, as well as other smaller or more randomised incidents, eg a tawny owl and pied wagtail. On Shetland, birds affected include eider ducks, gannets, bonxies (great skua) and gulls, and the bird flu outbreak at RSPB Minsmere has included black-headed gulls, common terns, Sandwich terns and one kittiwake.
A dead fulmar in Shetland.
Bird flu is hitting many birds that are already struggling. Seabirds, for example, are already under massive pressure from the climate crisis, declining numbers of fish, entanglement in fishing gear and development along our shores. Seabirds also tend to take longer to reach breeding age and have fewer chicks, meaning that it will take much longer for their numbers to build back up after bird flu. And the impact of the virus on a group can be staggering. Last year alone, one third of the Svalbard barnacle geese that spend their winter around the Solway estuary were lost to bird flu.
This also has international implications because Britain has a globally important number of seabirds. The UK, for example, is home to 56% of the world’s amber-listed gannet population, and Scotland has 60% of the world’s amber-listed great skuas.
https://www.discoverwildlife.com/animal-facts/birds/bird-flu-avian-influenza-guide