TWO Scottish island nature reserves surveyed their bird populations and noted a slight increase in seabird numbers in the aftermath of the 2022 bird flu outbreak.
Two of Shetland’s national nature reserves (NNR), Hermaness and Noss did a full count of their bird population to understand the impact of the devastating 2022 bird flu on different species. Both reserves were heavily impacted by the disease.
A total of 220 breeding pairs of great skuas, a seabird, were recorded at Hermaness, marking an increase from the 208 pairs in 2023. However, the population remains 77% lower than in 2018, when there were 955 breeding pairs.
At Noss, the second NNR, 80 breeding pairs were counted, representing an 83% decline from the 476 pairs in 2018, but an increase from the 69 pairs recorded in 2023.
“This year’s seabird census reveals the ongoing impact of the avian flu outbreak in 2022 and the painfully slow recovery of these populations which are likely to take years, if not decades, to reach pre-outbreak levels once again,” said Juan Brown, NatureScot operations officer.
Although no full count was done this year, gannet numbers at Hermaness in 2024 showed a slight increase. This species of seabird was badly hit by the virus.
The species' recovery is still set back by 20 years, with nests dropping from 29,562 in 2021 to 18,739 in 2023.
The NNRs announced that only one case of bird flu was found during the breeding season this year.
“In contrast to recent years, the small number of positive avian flu tests we have had this year have all been the H5N5 strain of the virus, rather than H5N1," said Brown.
"While we don’t yet know what the impact of H5N5 will be on wild bird populations, we are keeping a close eye on the situation and encourage people to report all sightings of sick or dead birds using the GB online reporting system.
"Sightings will help us track the spread of the virus and assess impacts on wild bird populations.”
Noss also surveyed its storm petrels using sound recording.
A total of 35 birds responded to call recordings played next to potential nest holes during a survey this year - the highest since this secretive seabird was found breeding on Noss in 2008. As only a proportion of birds respond, the population will be significantly bigger.
