They are known as flying barn doors because of their massive 8ft wingspan and were hunted to extinction more than 100 years ago before being successfully re-introduced.

Now a stricken sea eagle has made a successful comeback after being rescued for a second time in just two months after it was found on a grouse moor.

A gamekeeper out on his morning tasks on a Highland Perthshire estate found the satellite-tagged bird grounded and struggling.

The same bird had been rehabilitated and released by the Scottish SPCA in June after it came to the attention of staff on an Argyll estate.

On that occasion it was found to be suffering from dehydration and a malformed beak, which can cause birds problems in the wild.

Following the three-year old raptor’s release in June, satellite tag data indicated it had moved into Perthshire and NatureScot, formerly Scottish Natural Heritage, asked gamekeepers to look out for the majestic bird.

It was noted ranging freely in west Perthshire until Tuesday this week when the gamekeeper found it grounded while during his chores. The bird, which was wet and not moving, was taken to vets in Crieff and is now back in the care of the Scottish SPCA in the hope it can be rehabilitated and released once again.

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Alice Bugden, co-ordinator of the Tayside and Central Scotland Moorland Group, said: “When we were informed about the bird, the local gamekeepers and shepherds kept an eye out for it.

“We were told, in conversations with NatureScot, it still seemed to be moving, so that was good. However, it was then found in a poor condition by one of the keepers and he knew something had to be done. Looking at it, he didn’t know how much longer it would survive without veterinary attention.

“He doesn’t want to be named because he was just doing what anyone else would do in the circumstances. We hope it can be treated, will survive, and can take to the skies again.

“It is a good example of what can be achieved through dialogue between nature bodies and working land managers.”

NatureScot fitted the satellite tag to the raptor as part of continuing work related to the White-Tailed Eagle action plan.

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It was hoped the data would help inform ongoing work on the predation of lambs should the bird eventually establish a territory in Argyll. Sea eagles, which are also known as white-tailed eagles, are the UK’s largest bird of prey.

They are now a globally endangered species, with only around 10,000 pairs in the world, one third of which live in Norway. They were once a common sight across Scotland during the 19th century until persecution drove them to extinction in the UK.

The last was shot in 1918. After an absence of almost 60 years, they were reintroduced to the west coast in 1975, using Norwegian birds. The first sea eagles were reintroduced to Rum in 1975 and then Wester Ross between 1993 and 1998.

These birds have established an increasing breeding population on the west coast of Scotland. A third reintroduction of 85 of these magnificent birds to the east coast between 2007 and 2012 will help make the Scottish sea eagle population stronger and allow them to re-establish themselves across the country sooner. In 2013, for the first time in almost 200 years, sea eagles bred successfully in east Scotland.

Andrew Kent, who manages the Sea Eagle Management Scheme for NatureScot, said: “We would like to thank the gamekeeper and the Tayside and Central Scotland Moorland Group for their assistance in this case.

“Thanks to their quick thinking and communication this sea eagle now has a better chance of survival. “The bird is being cared for by the Scottish SPCA and we hope it will make a full recovery and be released into the wild again.

“This is a great example of where organisations can work together for the benefit of biodiversity.”