Tiny trackers are being fitted to the backs of seabirds in the UK as part of a Europe-wide effort to better understand their behaviour.

Scientists are tagging birds on the Fair Isle, Orkney and Colonsay in the Hebrides.

The project called Future of the Atlantic Marine Environment (Fame) also includes species on Bardsey Island in Wales and the Isles of Scilly.

The RSPB said Fame used technology similar to car sat nav systems.

Trackers are also being fitted to birds in Ireland, France, Spain and Portugal.

Dr Ellie Owen, a scientist working on a European Union-funded project, said very little was known about the movements of birds as they hunted at sea.

She said: "We know more about the journeys of albatrosses in the Southern Ocean than we do about some of the seabirds around our own shores.

"For example, we know how many kittiwakes there are in the UK, and we know they've declined by 30% between 2000 and 2010.

"But we don't know where these ocean travellers are going to fish for their chicks' suppers. But now, just when these birds need our help, we're on the cusp of filling this information void with vitally-important data."

'Dwindling food'

The tracking devices take a reading every 100 seconds, allowing the scientists to accurately pinpoint birds' movements between nesting colonies and the areas of sea the birds use to find food.

The RSPB said the technology was accurate to within a few metres.

In the UK, the Fame project has been tagging fulmar, shag, kittiwake, guillemot and razorbill.

Elsewhere, scientists are involved with other seabirds such as gannet, European storm petrel, Madeiran storm petrel and Balearic and Cory's shearwaters.

Dr Owen, who has fitted trackers to birds on Colonsay, said: "European seabirds face a variety of threats from dwindling food supplies, climate change, entanglement with fishing gear and pollution.

"By recording these birds' movements we are building a greater understanding of their requirements so we can begin to give these species the protection they need."