Satellite technology keeps an eagle eye on young birds' every move

Published on Tuesday 16 September 2008 20:09

AS THEY soar gracefully high above the cliffs and mountains of Mull, every beat of two young sea eagles' wings will be tracked using the very latest satellite technology.

The eagles – Scotland's largest bird, with a wingspan of up to eight feet are part of a tagging project that will unlock the secrets of the journeys they make.

Mull Eagle Watch and the Royal Society for the Protection of Birds (RSPB) Scotland have fitted satellite tags to Mara and Breagha, who hatched this summer at Loch Frisa, on Mull.

In a separate project, transmitters have also been fitted to a pair of osprey chicks raised at the RSPB's Loch Garten nature reserve in Strathspey.

On Mull, ornithologists will use the information gathered from the tags – which only weigh 70 grams – to follow the chicks' movements as they spread their wings and begin to explore Scotland's landscapes.

The public will also be able to watch the sea eagles' adventures online using interactive maps on the RSPB's website.

Mara, whose name means "sea" in Gaelic, and Breagha, which translates as "beautiful", fledged in mid-July but are still exploring their island home.

The sea eagles will also star in this year's series of Autumnwatch on BBC2.

David Sexton, the RSPB's Mull officer, said: "Now, with these tags, there's no escape. We'll know their every move.

"Although we're involving the public through the website, the driving force behind our project is that we wanted to know more about juvenile sea dispersal.

"The Mull project is a pilot scheme with just two chicks. We hope in the next year or two we will expand the project and all this data will be analysed very thoroughly.

"Already we know the male is exploring further afield than the female. I think within the next month we'll see the first trip off the island."

As well as tracking sea eagles on Mull, the RSPB is using satellite tags to monitor the progress of Nethy and Deshar, this year's pair of osprey chicks at Loch Garten, near Aviemore.

Unlike the sea eagle chicks, the young ospreys have left their birthplace to migrate up to 3,000 miles south to spend the winter in west Africa.

So far, the pair have made it to the south of England, where they have spent the past 24 days. They are expected to soon continue on their journey south.

Both the sea eaglets and young ospreys were fitted with their satellite tags by Roy Dennis, honorary president of the Highland Wildlife Foundation.

Mr Dennis said: "The big problem with tagging the young ospreys is that there's such a high mortality rate.

"We need to know much more about what they are doing in that first year or two of life and in the summer when the young ospreys stay in Africa."