Bird-breeding system off to a flier

Thor was conceived through the use of frozen sperm

Two Scottish bird-breeding experts have been celebrating the birth of the world's first eaglet through the insemination of frozen sperm.

Biologist Dr Graham Wishart and falconer Andrew Knowles-Brown were behind the breakthrough which led to the birth of Thor, eight days ago.

The eaglet, born at Mr Knowles-Brown's farm at Elvanfoot in South Lanarkshire, is also the world's first bird of prey not to be born in a laboratory after insemination with cryopreserved (frozen) sperm.

Dr Wishart, of the University of Abertay, Dundee, and internationally-renowned falconer Mr Knowles-Brown believe the breakthrough could help safeguard endangered birds of prey across the world.

The eagle is being hand reared

Dr Wishart said: "Artificial insemination of birds of prey using cryopreserved sperm has only been achieved twice before - both times by US based scientists."

These birds were an American Kestrel and Peregrine Falcon.

Dr Wishart continued: "We are particularly excited about Thor's birth because it shows that this complex science can be taken out of the laboratory and used by falconers and other aviculturalists in the field.

"We hope that our research will help safeguard endangered birds of prey such as the golden eagle."

The two experts had been working on the project for nearly four years before Thor was born to father Tallin, a five-year-old golden eagle and mother Meg, an eight-year-old Steppe eagle.

Thor's mum Meg is a Steppe eagle

Mr Knowles-Brown's sheep farm was 15 miles from a foot-and-mouth outbreak in Moffat, which meant Dr Wishart was unable to visit the farm to oversee key aspects of the process.

Instead the duo met at a service station where Dr Wishart gave his colleague the chemicals and a set of detailed protocols to follow in order to successfully freeze the sperm.

Mr Knowles-Brown explained: "Graham and I were in contact via email and telephone every day prior to artificial insemination of the eagle.

"He had devised a new approach this time, which involved freezing the sperm slowly to minus 20 degrees Celsius by placing the sperm samples in an insulated box that could be held within a domestic freezer.

"I then immersed the frozen sperm in liquid nitrogen for later use.

Thor's dad Tallin is a golden eagle

"This is an important extra tool that can be used to build up endangered bird populations in the relative safety of captivity before releasing them back into the wild.

"As eagles in the wild only increase their populations very slowly any captive manipulation which can rapidly produce offspring for release can only be of benefit to that species or any bird species."

He said the benefit of the use of cryopreserved sperm is that the sperm can be kept indefinitely.

Mr Knowles-Brown added: "One could envisage a situation where a particular species of bird of prey was in danger of extinction but the best chance of its survival came from artificially inseminating a bird in Australia with the sperm of a bird in the UK.

"With the technology demonstrated in our new system this is now a possibility."