‘Pirate of the seas’ Great Skua in big decline after bird flu
According to the RSPB, a formidable seabird, known as the “pirate of the seas,” has experienced a significant decline due to avian flu.
Great Skuas, renowned for their aerial prowess in scavenging food along the UK’s coastlines, saw a staggering 76% decrease in their numbers in 2023, as outlined in a report by the charitable organization.
The avian flu outbreak in 2021-22 took a toll on various seabird populations, including Gannets and Roseate Terns, resulting in substantial reductions.
Before the outbreak, the populations of these three species had been on the rise. However, the H5N1 strain of avian flu, which affected wild birds starting in the summer of 2021, led to the deaths of thousands of creatures.
The RSPB emphasizes that avian flu represents a significant and immediate threat to multiple seabird species, alongside other existing challenges they face.
Jean Duggan, the RSPB’s avian influenza policy assistant, underscores the seriousness of the situation, describing it as a wake-up call to the severity of avian flu and its compounding effects with other threats.
The RSPB’s survey conducted from May to July 2023 examined 13 bird species and concluded that avian flu was responsible for the decline in Great Skuas, Gannets, and Roseate Terns, while also likely contributing to reductions in Sandwich and Common Terns.
Compared to a significant census of bird populations conducted between 2015 and 2021, Gannet populations have declined by 25%, Roseate Terns by 21%, Sandwich Terns by 35%, and Common Terns by 42%.
Almost the entire UK population of Great Skuas live in Scotland. In 2022, at least 2,591 Great Skuas died – 1,400 from one colony alone on Foula island, Shetland.
The total number in the UK has declined from 9,088 to 2,160.
Ms Duggan highlighted that Britain was pivotal in protecting the birds worldwide because so many breed in Britain.
“It’s empowering to realize that if we take the right actions in the UK it will benefit global populations to a very significant degree,” she says.
Gannets were also badly affected in 2022, with 11,175 killed in Scotland and an estimated 5,000 mortalities at Grassholm in Wales.
In 2023 the total number counted in the UK had declined by 25%, going from 227,129 to 171,048.
Avian flu become less acute in the UK in recent months, but it has caused mass mortalities of birds in other parts of the world.
In January it was detected in elephant and fur seals in Antarctica for the first time.
“While the virus is still present globally, UK birds are still at risk, and the virus will continue to mutate. We need to consider it a long-term threat,” says Ms Duggan.
Climate change, mortality linked to fishing, the effects of offshore wind developments, and a reduction in the availability of food are other threats facing UK seabirds, according to the RSBP.