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31 Aug 2023

Significant seabird census completed at St Kilda

A woman stands at the top of a cliff with a tripod, looking down a very steep slope to the blue sea below and seabirds perched on the rocky shore.
To carry out the census, the team hiked to every nook and cranny of the main island. | Image: Ellie Owen
The census took staff and volunteers around 1,400 hours to complete and it highlights the importance of taking action to protect seabirds.

As part of our vital work to help protect Scotland’s National Nature Reserves, we recently completed a census of cliff-nesting seabirds at St Kilda. The census – the first fully comparable survey since 1999 of all four islands that make up St Kilda – is part of the Love for Nature project, an ambitious programme of nature conservation work that aims to safeguard Scotland’s natural heritage. The census has been carried out by the Trust’s expert seabird staff and dedicated volunteers.

Almost 93 years after the St Kilda evacuation on 29 August 1930, when the last islanders left the archipelago, this census has identified a 61% decline across four species of cliff-nesting seabirds: fulmars, guillemots, razorbills and kittiwakes.

At one time, St Kilda was the only place in the UK that was home to fulmars. Our census team were dismayed while carrying out this latest count as it became clear there were far fewer fulmars than they had hoped to find. From their data, they realised that fulmars have declined by a huge 69% since the 1999 census. For every fulmar nest they were counting, there should have been three more.

A fulmar sits in its nest on the ground on a grassy cliff top. It looks a little like a large gull but it has a much larger beak with a large bump on the top.
The 2023 census has shown an alarming decline in fulmar numbers since the 1999 count. | Image: Craig Nisbet

The decline is even greater for the kittiwake, a small gull with a lemon-yellow beak. Our team has found that kittiwake numbers have declined by 84% since 1999. Guillemots and razorbills, which huddle together on the cliffs in large numbers during the summer and contribute the droning, gargling noises of the seabird colony cacophony, have also declined by over 35%, making the islands that bit quieter.

Seabirds have long been synonymous with St Kilda, and have even affected the islands’ architecture with the construction of the unusual stone buildings (cleits) to store produce and fowling equipment. Before the evacuation of the last remaining 36 St Kildans in August 1930, thousands of people had lived on the island over the centuries – farming, fishing and, most importantly, harvesting seabirds and their eggs.

To carry out the census, the team counted seabirds from land and sea. They hiked to every nook and cranny of Hirta, the main island in the archipelago, and then took to the waves, using binoculars from boats to count seabirds on the cliffs of the smaller islands. The census took around 1,400 hours to complete during the first three weeks in June. Three members of the Trust team, including St Kilda’s Seabird Ranger Craig Nisbet and Senior Seabird Officer Ellie Owen, were joined by six highly skilled volunteers and other Trust staff.

A man lies on his side on a rocky slab close to a sea inlet. He is using binoculars to count seabirds on the rocks on the other side of the water.
Counting seabirds | Image: Craig Nisbet

Susan Bain, the Trust’s Western Isles Manager at the National Trust for Scotland, said: ‘The decline in seabirds on St Kilda is not only concerning from a natural heritage point of view but also from a cultural heritage point of view. The exploitation of seabirds was integral to the community that lived on St Kilda; it is what allowed them to settle and live on such a small island for thousands of years. They ate the meat and eggs, used the oil for light and ointment, and traded the feathers. Many of the few songs that have survived tell of fowling expeditions and the dangers associated with it.’

“A decline in seabirds diminishes the World Heritage Site and is a clear signal that our marine ecosystem is under immense pressure.”
Susan Bain
Western Isles Manager
A woman with short fair hair stands on a sandy beach beside the waterline. She wears a navy National Trust for Scotland jacket and jeans.

Ellie Owen, the Trust’s Senior Seabird Officer, commented: ‘The census took a lot of time and resource to complete but it’s incredibly important that we capture this data to identify how wildlife is faring across the places our charity cares for. It’s only by identifying the declines and trends in our seabirds that we can begin to consider how to help them. We’re grateful to our supporters, including Tim and Kim Allan who sponsored this census, for enabling us to continue to understand, care for and protect our natural heritage.

‘We don’t have a full picture of what has led to the decline on St Kilda, but climate change has certainly played a part, affecting elements such as the food supply in the surrounding sea. Declines in natural prey such as sandeels are likely also impacting seabirds, and closing Scotland’s waters to the foreign-based sandeel fishery would be a powerful step to helping our seabirds. We also need to work with the government and fisheries to reduce the accidental bycatch of fulmars on longlines, using available mitigation measures.

“I would encourage every individual across the country to be curious as to how they can play a part in saving Scotland’s seabirds, to ensure future generations can continue to marvel at them.”
Ellie Owen
Senior Seabird Officer
A woman wearing a red helmet and red floatation jacket stands on a rocky ledge beside a sea inlet. Large rock stacks stand just off shore behind her.

Ellie continued: ‘With over 1 million seabirds at places in our care, we know how important taking action is – whether it’s following the Check, Clean, Close rule that keeps islands safe from people accidentally introducing predators such as rats, or giving seabirds space from both people and dogs when visiting colonies or beaches.

‘People can also become an active part of the research effort by taking part in seabird citizen science projects, like our charity’s Seabirds, Camera, Action initiative. Here, we are asking our supporters to take and submit photos of seabirds carrying fish at any of the Trust’s places to help us monitor what food seabirds are feeding their chicks. And one of the best ways to help currently is to get involved in any number of wildlife campaigns – from sharing responses to the Scottish Government’s sandeel fishing consultation, to supporting the Trust’s Save our Seabirds campaign.

‘Visitors to St Kilda and our other coastal places will enjoy incredible wildlife experiences. There are now 20,712 fulmars on St Kilda alone ... but there used to be 66,934. It’s vital that we don’t just accept this and that we all do everything in our power to help nature flourish, and to help conserve and protect Scotland’s seabirds.’

The Love our Nature project is supported through funding from players of People’s Postcode Lottery, who have now raised more than £1 billion for thousands of charities and local good causes. This includes a total of over £2.5m for the National Trust for Scotland since 2014, to support our work to enrich and protect Scotland’s landscapes and wildlife, for which we are very grateful.

The role of the National Trust for Scotland’s Senior Seabird Officer and activity is supported by Tim and Kim Allan, members of the National Trust for Scotland’s Patrons’ Club, a generous group of donors who support our conservation charity.

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