Isles of Scilly Seabird Strategy

Think Scilly and think seabirds! From puffins to shearwaters, Scilly’s seabirds are a big part of what makes the islands special, and the Isles of Scilly Wildlife Trust has a huge commitment to them.

Since 2000, Dr Vickie Heaney has been studying the seabirds of the isles. She’s our Seabird Ecologist, undertaking annual breeding seabird population surveys for sample sites, and recording the productivity of these birds. Our Conservation Manager, Jaclyn Pearson was at the heart of the project that successfully eradicated rats from St Agnes and Gugh in 2013, when she led the Isles of Scilly Seabird Recovery Project whilst working for RSPB.

The Isles of Scilly has seen as many as 15 species of breeding seabirds over the years. Much of our archipelago is designated as a Special Protection Area and Ramsar site under international agreements in recognition of this importance. However, many of our seabird species are in trouble.

We organised a full survey of all of the Special Protection Area’s breeding seabirds in 2023, funded by Natural England, RSPB and the Isles of Scilly National Landscapes partnership. The interim report is now published and available by clicking the link below. This shows increasing numbers of Manx shearwaters and storm petrels, however there are worrying declines in shags and all our gull species. Furthermore, no breeding terns were recorded this year, following long-term declines in our common tern population. At one time we had up to four species of terns nesting regularly in the islands.

However, the work on St Agnes and Gugh shows the way forward. Rats are devastating predators of seabirds, particularly the burrow-nesting Manx shearwaters and storm petrels. Whilst both species have increasing populations in Scilly, with more than 1,000 breeding pairs of each, this is just a fraction of the historic shearwater breeding population – in the 19^th Century, between 100,000 and 150,000 pairs of shearwaters were thought to nest in Scilly, so our current numbers are just a fraction of what the islands once held.

We believe we can fully reverse this shearwater decline through rat eradication on all the rest of the off-isles, inhabited and uninhabited. We are now working with the RSPB, Tresco Estate, Duchy of Cornwall, Council of the Isles of Scilly, Natural England and the communities of Bryher, Tresco and St Martin’s. The Isles of Scilly National Landscapes partnership is central to coordinating this work, which is the greatest priority for the Isles of Scilly Seabird Strategy.

Read more about the work we do for our seabirds of Scilly in the Reports below!