Larne Lough SPA
Swan and Blue Circle Island in Larne Lough Photo: RSPB images/David Wootton

Happy New Year and welcome to our new island blog series where we will introduce each and every one of the 42 island Special Protection Areas (SPAs) we’re working on and tell you what makes them quite so special.

We start with one of the smallest SPAs covered by this project, which are the two islands (Swan and Blue Circle) found within the Larne Lough SPA in Northern Ireland. These islands are designated for breeding common terns (Sterna hirundo), sandwich terns (Sterna sandvicensis) and roseate terns (Sterna dougallii) as despite their size they hold nationally important numbers of these species. Both sites are managed by the RSPB but there is no public access to these islands in order to protect the terns from disturbance.

Swan Island is a low-lying natural island only 0.14 hectares in size with a shingle shore which RSPB staff can beach their boat on in order to land and carry out habitat management works. There is high competition for breeding space on the island and nests around the edge of the island are vulnerable to high tides and waves caused by stormy weather. Management work on both islands involves removing vegetation so there is more exposed bare ground which the terns prefer to nest on as their eggs and young are camouflaged against it.

Swan Island, Larne Lough

Landing on Swan Island   Photo: Tessa Coledale

Blue Circle Island, which is just four times larger was man-made using waste material from the local quarry. This process started in the 1980’s with breeding seabirds first appearing in 1993, although flooding and erosion meant the island wasn’t completed until restoration work finished in autumn 2018. The rock armour design makes it look a bit like a lumpy rock doughnut with a central flat vegetated area. It is hard to imagine that it is covered in over 1000 pairs of terns come the summer including Northern Ireland’s only known breeding pair of roseate terns.

Blue Circle Island, Larne Lough

Blue Circle island   Photo: Tessa Coledale

Roseate terns are the rarest breeding seabirds in Europe. Historically during the late 1980’s Larne Lough held around 35 breeding pairs of roseate terns. Concrete nest boxes have been added to Blue Circle Island to attract more of these beautiful birds in the future. Both islands also have electric fences installed to deter otters from entering the tern colonies as one otter could decimate a colony very quickly through both predation and disturbance. Eurasian otters are native to the UK and protected by the Wildlife and Countryside Act 1981.

RoseateTerns RSPB images TimMelling

Roseate Terns   Photo: RSPB images/Tim Melling

The Biosecurity for LIFE project is just working on preventing invasive non-native mammalian predators reaching these islands. We’ve helped the RSPB write a biosecurity plan for the islands in Larne Lough SPA which identifies where the main risk pathways are. As both islands are around 500m from the shore and Larne Lough is a sheltered sea lough, weak currents mean that it would be possible for house mice and brown rats to swim out to them. The biosecurity plan also details biosecurity surveillance measures that need to be put in place to detect if this happened. These measures, namely wax blocks have been installed but more work needs to be done on increasing the checking rate and improving awareness to the general public around the lough side.



April 2020

Skokholm, Skomer and Middleholm

Together these islands are estimated to hold a remarkable 67% of the world population of breeding Manx shearwater. These birds are diurnal but will only come ashore or go out to sea under the cover of darkness and nest underground so you’re unlikely to see them when you visit the islands unless you stay overnight. You will see that the ground is covered in burrows and is therefore extremely fragile so take care to stay on the paths when you visit. Skokholm is also home to the fourth largest storm petrel colony in the UK, holding 8% of the UK breeding population. These birds’ nest in crevices in stone walls or quarries and are also nocturnal when on land to avoid predation. The islands most famous resident however is the puffin, these birds nest underground but come out in the day so you are likely to see rather a lot of them if you visit between April and July. All these ground-nesting species are particularly susceptible to invasive non-native mammalian predators, they would not survive if rats, mink or stoats arrived on the islands.

March 2020


Grassholm is one of those islands that assaults your senses upon approach with both the smell, noise and sight of over 36,000 pairs of gannets. On a round island boat trip you’ll see them on their nests or flying overhead like aeroplanes before folding their wings back and diving at speed to catch their prey in the surrounding waters. 6.8% of the world population of Northern gannets breed on this lump of rock just 10 hectares in size. In fact, the majority of the island is now white in colour due to the animals and their guano, with only a relatively small strip of grass remaining where they are yet to colonise. Grassholm is the third largest gannetry in the UK after the Bass Rock and St Kilda – two other sites we’re also working on.

March 2020

The Farne Islands

Lying only a mile off the Northumberland Coast, the Farne Islands archipelago hosts one of England’s most impressive seabird colonies, managed by the National Trust. Depending of the state of the tide, the Farnes boast between 15 and 28 islands, the largest being just 16 acres in size. Onto these small isles, an assemblage of over 160,000 seabirds crowd together each summer to breed.

Illustration of birds

Contact Us

If you’d like more information or would like to report a sighting of an invasive predator please contact us using the form below: