The wader is one of the fastest declining birds in the UK and its lowland-breeding populations are especially at risk. 

Earlier this summer precious eggs, which would otherwise have been destroyed to help reduce the risk of bird strikes to aircraft, were brought by Natural England staff to the new facilities at Deepdale Conservation Trust, near Brancaster.

Here they were hatched before the young birds were reared in polytunnel aviaries, until they were large enough to be released.

At around two months of age, several groups of curlews have been released on the Sandringham Estate and at Wild Ken Hill.

Each of the 56 birds was fitted with a unique metal leg ring, which can be read by birdwatchers in the field.

A number were also fitted with small GPS tags, allowing their movements to be tracked.

The scheme is run by a partnership between Natural England, the Defence Infrastructure Organisation, the British Trust for Ornithology, the Sandringham Estate, Wild Ken Hill and Deepdale Conservation Trust.

Joseph Hamer, senior ecologist with the Defence Infrastructure Organisation, said: “The Eurasian Curlew has become an increasingly scarce breeding bird in the UK lowlands, and supporting the conservation of species such as this iconic wader is part of the nature recovery work we carry out across the defence estate.

“This project also ensures we maintain full operational capability across our airfields in East Anglia by removing the risk of aircraft bird strike.”

Chrissie Kelley, head of aviculture at Deepdale Conservation Trust, said: “It is a privilege to work with these beautiful birds and contribute to efforts to save their lowland populations.

“The breeding song of the curlew is among the most distinctive sounds in the British countryside. It would be a tragedy for it to be lost from Norfolk.”

Sam Franks, senior research ecologist with the British Trust for Ornithology, said: “Not only is the project playing a role in boosting the breeding success of this iconic bird of the UK, we are learning a huge amount about the early months and years of young curlew which was previously unknown.”