ONE of Scotland’s rarest seabirds requires urgent action to halt its decline, according to a new report published yesterday.

Arctic skuas are known as the “pirates of the seabird world” because they steal their food from other birds.

The birds, which breed only in Scotland in the UK, take advantage of the diving skills of other seabirds to catch small fish such as sandeels, before giving chase and forcing the pursued bird to drop its meal.

The State of the UK’s Birds 2020 (SUKB) report shows the species, which breeds in the far north of Scotland and Northern Isles, has suffered an 80% decline since 1986 and a 30% decline in the last decade.

Already on the UK red-list of birds at greatest conservation concern, the latest figures reveal previously well-occupied colonies have either disappeared or been reduced to only “a handful” of pairs, “threatening their long-term future as a breeding species in Scotland”.

Arctic skuas’ breeding success is thought to have suffered from a reduction in food, particularly sandeels, available at the crucial time of year they need to feed their young.

A reduction in sandeels is thought to have affected kittiwake populations, which in turn has had a knock-on effect as they are one of the species skuas steal food from.

Ben Darvill, Scotland Development and Engagement Manager for the British Trust for Ornithology, one of the SUKB partners, said: “All of the UK’s Arctic skua are in Scotland and the reasons for their decline are complex.

“Food is likely to be an issue, and some colonies of the birds such as the auks and terns that the skuas chase have not done well.

“It’s too early to say they could become extinct (as a breeding species) but the direction of travel is a big concern.

“Some of the colonies already have disappeared and we are seeing a concerning direction of travel for some of the remaining colonies.

“We need to act fast. This is the most declining species of breeding seabird in the UK, hence the need for urgent research to try to act before it is too late.”

The SUKB report - which shows the latest results from bird surveys and monitoring studies - shows the distribution and numbers of birds in Scotland are changing dramatically, with many species showing worrying declines.

The report reveals that Scotland’s seabirds continue to show mixed fortunes. In addition to Arctic skuas, the Seabird Monitoring Programme (SMP) shows concerning long-term declines in birds that feed on sandeels, including kittiwakes, shags and Arctic terns.

The seabird indicator, which uses SMP data and covers 11 of the 24 seabird species in Scotland, shows the 11 species declined on average by 32% between 1986 and 2017.

In better seabird news, gannet populations are doing well, with an increase in both numbers and range. Marwick Head in Orkney is one of a number of new and expanding gannet colonies which have contributed to the good fortune of this iconic species.

Scotland’s upland birds are also struggling. Lapwing breeding populations declined by 56% between 1995 and 2018, while curlew numbers declined by 59% 1995 and 2008 and 20% from 2008 to 2018.

The report contains better news for some species. In Scotland, an increase in breeding tree pipit populations of 80% between 1995 and 2018 and willow warbler populations of 25% are in contrast to marked declines in Wales and England.

Cuckoo numbers have also increased by 54% in Scotland over the same time period but have declined in England, likely due to the loss of food resources in more intensively managed lowland environments there.

Fiona Burns, lead author of the SUKB 2020 report, said: “The UK’s birds are telling us that nature is in retreat. The continuing losses seen across many species are not sustainable and more needs to be done to stop the declines and help populations revive and recover.

“These findings are in line with our earlier State of Nature 2019 report which found that 41% of all UK species are declining. More action is needed."