The calls of the small birds were recorded for the first time on a group of Islands in The Minch.
Conservationists hope that the sound of the storm birds’ “Chur ring” is an indication that an effort to the eradication of the rats working on the Shiant Islands.
The black rats are not native to the Islands of Lewis and to the offspring of rats that came ashore from shipwrecks in the 1900s.
Storm petrels are not found where there are rats that eat their eggs.
On the Shiants, colonies of puffins, razorbills and guillemots were in decline, while the Manx shearwaters and up to now, the storm birds were not found.
RSPB Scotland, Scottish Natural Heritage and the Nicolson family, the owners of the Islands, the secured financing to start the rat eradication work in the year 2015.
They hope that it will be possible to declare the Islands rat-free in March of next year.
Storm birds, which are slightly larger than a Sparrow, had been seen flying past the Shiants.
To encourage them to breed on the Islands, conservationists played, the sound of their calls from a speaker.
To listen to this summer, real storm birds’ Chur ring, and the birds seen, in a cave, the environmentalists, with night vision equipment.
Ed Marshall/RSPB Images
Dr. Charlie Main, senior project manager, Shiant Isles recovery project, said: “The Chur-ring of the storm bird is very strong and we are pleased that it was included on the Shiants in this summer.
“While we are still in the Islands officially declared rat-free, these calls indicate that all of the biosecurity work that we do to keep the Islands predator-free and make ideal breeding sites for seabirds pays off.”
She added: “The long-term goal is to establish a breeding colony of storm petrels, in the case of the Shiants.”
Dr. Andrew Douse, policy and advice manager, Heritage in ornithology at Scottish Natural said the first shot with the birds was “very welcome”.
He said: “the storm birds only occur on Islands without rats, which means that they are very vulnerable to the impacts arising from invasive species such as these.
“The Shiants are an ideal breeding location for birds and hopefully they will be an important base for this species.”