The nightingale’s song has been captivating people for centuries, and a good place to hear this rapidly declining bird is the RSPB’s Highnam Woods nature reserve, near Gloucester.

Eight of the birds have been confirmed singing this spring at the ancient woodland, near Gloucester, which the RSPB is managing to make more nightingale-friendly.

Site manager Hannah Morton said: “It’s a bird that is in trouble, it’s a bird we know we have to help and it’s really satisfying to know our hard work has been rewarded in this way.”

The nightingale has recently been added to the Red List of Birds of Conservation Concern – the highest category. The British population has fallen by about half since the mid-1990s, probably because the amount of suitable habitat for the notoriously picky bird is shrinking.

Nightingales like the combination of open glades and scrubby thickets often found in coppiced woodland, a traditional form of management that largely ceased after the Second World War.

Work to make Highnam Woods more attractive to nightingales has included coppicing small parcels of woodland on a ten-year rotation, and re-wetting parts of the reserve – the birds are attracted to wet coppice and scrub.

The work has halted the steady decline of nightingales at Highnam Woods, which has occurred since 2000.

Miss Morton said: “We have been waiting for the last three or four years hoping there would be an increase and this year there has been. Last year we thought we had eight but we couldn’t be certain but this year we are sure. And there are two singing where we have done the re-wetting, which is really good news.

“It’s looking really positive and we’re absolutely delighted we have helped halt this decline.”

The greatest concentration of nightingales is in South East England, and Gloucestershire is at the extremity of the bird’s range – few of these summer migrants venture north or west of a line running loosely from Dorset to the Wash.

The nightingale’s famous song – a succession of high, low and rich notes few other birds can match – can be heard during the day and at night. The bird itself, in contrast to its song, is unspectacular, looking something like a large, all-brown robin.