Food shortages caused by climate change could wipe out rare Arctic skuas in Scotland, according to new research.
The species, which has its UK stronghold in the far north of the country, has been suffering major declines over recent decades.
The latest figures suggest numbers have crashed by more than 80 per cent in the past 20 years.
As part of the new study, researchers from the RSPB’s Centre for Conservation Science analysed data between 1992 and 2015 from 33 Scottish Arctic skua colonies.
These colonies, in Orkney, Shetland and Handa, hold around a third of the UK’s entire breeding population of Arctic skuas.
The scientists found the main driver of the decline is a huge drop in breeding success.
They believe this has been caused by a reduction in the amount of food – particularly sandeels – available to the birds during their crucial breeding season.
Dr Allan Perkins, senior conservation scientist at RSPB Scotland and the study leader, said: “We have known for many years that Arctic skuas numbers have been going down in Scotland but this study reveals just how bad the declines have been at some of their most important breeding sites.
“Lack of food has been the biggest pressure for these birds and shows just how vulnerable our seabirds and marine life are; as sandeel numbers have declined around these key north-east areas in Scotland the whole food chain is impacted.
“If these sharp declines continue, it’s possible that Arctic skuas will be lost as a breeding species in Scotland.”
Arctic skuas are medium-sized seabirds with pointed falcon-like wings and long pointed tail feathers. They are rare breeding birds in the UK, and are on the red list for species of conservation concern.
Arctic skuas are known as the pirates of the seabird world because they steal food from other species – a behaviour called kleptoparasitism.