From Rare Bird Alert
Calling European storm petrels have been recorded for the very first time on the Shiant Isles, Scotland this summer, an important milestone for the Shiant Isles Recovery Project, which is working to attract these small seabirds to nest on the islands. The characteristic “churring” call of storm petrels was heard from burrows, their breeding habitat, an encouraging sign that the project’s conservation work is paying off.
The EU LIFE+ funded partnership project between RSPB Scotland, Scottish Natural Heritage, and the Nicolson family, the custodians of the islands, began in 2014 to provide safe breeding grounds for Scotland’s globally threatened seabirds on this cluster of islands in the Minch, five miles off the coast of Harris. A population of invasive non-native black rats on the islands were thought to be limiting the breeding success of the colonies of puffins, razorbills and guillemots, whilst storm petrels and Manx shearwaters were not found there at all.
Following a rat eradication programme in the winter of 2015/16 the project has been focused on monitoring how the wildlife has responded, ensuring the biosecurity of the islands, and attempting to attract storm petrels and Manx shearwaters to breed, as there is ideal nesting habitat for them. It will be March 2018 before the islands can be officially declared free of rats, provided none are found between then and now.
Storm petrels are little bigger than sparrows and only come to shore in summer to breed. Scotland’s internationally important population currently only nests at a limited number of potentially available sites on offshore islands because of their vulnerability to predation. They are known to abandon and avoid nesting sites where rats or other ground based predators are found.
While these small seabirds have been recorded flying past the Shiants for many years by the Shiants Auk Ringing Group prior to the recovery project beginning there was no evidence that they were landing on the islands or attempting to nest there. Last summer night vision cameras captured footage of several of these small seabirds, but this is the first year their churring has been heard in burrows.
This summer a speaker broadcasting a recording of a storm petrel churring (hear storm petrels here) was placed by some boulder scree near the shore and played throughout the night. The project hoped that this would not only attract storm petrels to the area so they could discover the nesting sites, but also to settle and start a breeding colony there. Calls from birds were recorded from three separate sites close to the speaker.
A night vision camera also captured footage of a storm petrel displaying nesting behaviour; looking relaxed and heading into a burrow. While it’s possible that birds may have successfully bred on the islands this summer confirming this is difficult due to them only entering and leaving their nest burrows in darkness and would have risked disturbing them due to the locations of the calls.
Dr Charlie Main, Senior Project Manager for the Shiant Isles Recovery Project said: “The churring of a storm petrel is very distinctive and we’re delighted that it’s been recorded on the Shiants this summer. While we are still some way off the islands being officially declared rat free these calls indicate that all the biosecurity work we’re doing to keep these islands predator free and make them ideal breeding sites for seabirds is paying off.
“It’s even more exciting to think that the birds may have bred on the islands this year, although the risk of disturbing nesting birds meant we were unable to confirm this. These calls are very positive signs for the future and we hope that next year we’ll be able to record even more calls and footage of the birds. The long term aim is to allow a breeding colony of storm petrels to establish at the Shiants.”
Dr Andrew Douse, Policy & Advice Manager, Ornithology at Scottish Natural Heritage said: “The return of storm petrels as a breeding species on the Shiants is one of the key aims of the project for SNH, so the news of birds recorded calling is very welcome. Storm petrels only occur on islands without rats, which means that they are very vulnerable to the effects that arise from invasive species such as these. The Shiants are an ideal breeding location for storm petrels and hopefully they will go on to become an important stronghold for this species.”
In the Channel Islands we have a healthy population of storm petrels on (rat-free) Burhou (Alderney) but the presence of rats elsewhere, even in otherwise suitable areas of the coast like Plémont, mean that we have nowhere near as many as we could have in the islands with adequate management.