IT has stunned researchers after being blown to the coast of Norway on a feeding expedition – and then returning to its Scottish nest within 24 hours.

The tiny storm petrel – the UK’s smallest seabird – was one of 42 fitted with a GPS tag as part of a landmark RSPB Scotland study on Mousa, an uninhabited island in Shetland.

Experts discovered its foraging trips generally lasted between one and three days, and ranged up to 300 kilometres from the colony. However, one bird travelled almost 400 kilometres to the Norwegian coast.

Thought to have been blown off course in a storm, the petrel, amazingly, returned to its nest inside a day.

The conservation charity said its pioneering research had provided new insights into the animals, which weigh just 25-30 grams – the same as three £1 coins.

For the first time, several years of data were collected on their movements at sea thanks to the GPS tags, which, at less than one gram, do not negatively affect the ability to fly or forage.

Because storm petrels are active at night, the satellite data offered unique clues about their behaviour, as well as valuable lessons about how they might be protected in future.

Mark Bolton, RSPB’s principal conservation scientist and author of a new study paper, said: “This was ambitious research and provides the most comprehensive insight into how these tiny birds use our vast marine environment to feed and raise their young.”

Britain, and Shetland in particular, is key to the species.

The colony studied on Mousa is home to almost 11,000 pairs, representing around 2.5 per cent of the entire global population.

As part of the study, a series of nest boxes were built, allowing the birds to be easily captured, tagged and released.

They were then tracked over four breeding seasons between 2014 and 2017.

Researchers expected the animals to use waters at the edge of the continental shelf to the west of Shetland, where high concentrations of storm petrels have been reported in previous decades from boat surveys.

However, the study, which was published in the journal Bird Conservation International, found that the Mousa birds concentrated in two main unexpected sites.

One was 110 kilometres to the south of the colony and probably represented the areas which birds were using for feeding on plankton and small fish.

The other high concentration occurred in the waters surrounding the colony and reflected the commuting flights of the birds to and from their nests at night.

It is thought their nocturnal habits could indicate that past surveys have missed their reliance on inshore waters.

RSPB Scotland also said the discovery that birds occur in such high numbers so close to shore at night “means extra thought should be given to whether human activity might have an impact” on them.

Mousa is designated as a European Special Protection Area (SPA), with storm petrels named as a protected feature.

But, while much of the areas used by the Shetland birds is also specially protected for other forms of marine life, the new research shows they are also key for storm petrels.

Commenting further, Mr Bolton said: “The new insights about their behaviour demonstrate the value of fundamental science as well as providing an amazing window into the travels of our smallest seabird.”

Alex Kinninmonth, RSPB Scotland’s Head of Marine Policy, said: “Embracing this game-changing technology has allowed us to build a more complete picture of the lives of these elusive birds.

“Scotland’s seabirds are already in trouble and face an uncertain future, so expanding our knowledge of where they go at sea and why is vital.”