Some seabird species have returned to Scotland in lower numbers this breeding season following the devastating outbreak of avian flu last year, according to early monitoring by NatureScot and its partners.
Despite recent concerning outbreaks of the virus in England, there is cautious optimism that colonies in Scotland have so far avoided the high number of deaths observed last summer.
However, early surveillance of seabird colonies suggest that some species have returned in significantly lower numbers than in previous years, with great skuas being especially hard hit.
While counts are ongoing, initial observations from some of the main sites in Shetland suggest significant breeding population declines for great skua – for example, it is estimated that up to 90% of the population on Hermaness may have been lost. Scotland supports 60% of the world breeding population of great skua. As a result, a temporary suspension of ringing and research activities has been put in place for great skua to minimise unnecessary disturbance or stress to these vulnerable populations. Counts and productivity monitoring will continue as these activities will aid understanding of the impacts of the outbreak, and can be carried out with minimal disturbance.
There are also concerns about unusual behaviour in terns, with fewer birds than usual returning to sites across Scotland, including NatureScot’s Isle of May and Noss National Nature Reserves (NNRs), and their return coming later than expected. On Noss, tern nesting was late but some eggs have now at last been laid. But on the Isle of May, as yet there has been no nesting this year, while on Rum the terns have deserted without laying any eggs. Targeted surveys of breeding seabird populations are currently underway, and will help to better understand the extent of the impact.
Posted On: 16/06/2023