'Catastrophic': report reveals impact of avian flu on UK's seabirds

The UK has lost more than three-quarters of its great skuas on surveyed sites since bird flu struck, according to the first report quantifying its impact on seabird populations.

- Phoebe Weston

The deaths happened in the space of two years, after the outbreak of H5N1 in 2021. The UK is internationally important for seabirds, holding most of the world's nesting great skuas. The global population is about 16,000.

"To have that level of loss in a population we have international responsibility for is quite catastrophic," said Jean Duggan, policy assistant on avian influenza at the Royal Society for the Protection of Birds (RSPB). "Globally, it's very significant and has a knock-on effect for populations across the globe." The UK also holds more than half of the world's northern gannets, which declined by 25% across the sites surveyed, according to the report by RSPB, the British Trust for Ornithology and other conservation bodies.

Gannets nest in large colonies and there are few of them in the UK as a whole, which means they are particularly vulnerable to the spread of disease. In Wales, the number of nesting northern gannets crashed by 54%. "For the gannets and great skuas, we knew it was bad, but it's worse than we thought," said Duggan.

The report also found the virus had caused a 21% decline in the UK population of roseate terns.

Seabirds are typically long-lived and do not reach breeding age until they are about five years old. They generally have only a few chicks, so populations take longer to recover from setbacks.