Scientists are using the latest technology to unveil the mystery migration of one of the UK’s most elusive and threatened birds. 

Nightingales, celebrated for their beautiful song, have declined by nearly 60% in the last 15 years alone, and scientists are racing against time to find out why.

The birds are long distance migrants, leaving their stronghold in the south and east of England for the perilous journey to west and central Africa in the Autumn. Anglian Water teamed up with the British Trust for Ornithology two years ago to start tagging them electronically in order to find out exactly when and where they go.

Now advances in miniature technology mean the birds will this year be fitted with the most accurate geo-locater devices yet, bringing greater accuracy to the scientific data.

Over the next two weeks Anglian Water and BTO staff will be attaching the new tags to nightingales at Anglian Water’s Grafham Water reserve where habitat for the birds is managed by the Bedfordshire, Cambridgeshire and Northamptonshire Wildlife Trust.

Mike Drew, Anglian Water wildlife scientist, said: “The technology is getting better all the time and these latest tags mean our work tracking nightingales is going to be much more accurate.

“Alongside the BTO we have already gained real insights into the migration of this enigmatic bird. But we are now much better able to trace which route they take on their journey – I can’t wait to get the data next Spring and see a detailed map of their travels.

“We’re extremely proud of the nightingales we have at Grafham Water, and that is all thanks to the partnership we have with the local Wildlife Trust. It is vitally important for us as a company that as well as protecting the water supplies of our region, we also protect the wildlife nearby. We feel that it’s part of our responsibility and when we have asked our customers, they agree.”

To coincide with the start of this year’s tagging, the BTO is also unveiling a new guide to managing habitats for nightingales featuring all the latest knowledge of what the birds need to survive.

Paul Stancliffe, from the BTO, said: “Being able to track these birds as they move between Africa and Grafham Water, seeing the routes they take, where they stop to rest and feed, and for how long, would have been the thing of dreams only a few years ago.

“The use of these new tags is incredibly exciting; they should help us to inform future conservation action to reverse the declines seen in populations of this iconic bird.

“Our work studying nightingale habitats here in the UK will also support conservation efforts, not least through our new booklet on ‘Managing Scrub for Nightingales’, which is being launched on Wednesday, 29 April.”

Wildlife Trust BCN Senior Reserves Officer Aidan Matthews said: “We have known for some time that nightingales are in trouble, and numbers continue to fall. Habitat degradation and loss plays a big part - a lot of land isn’t managed in the way that it used to be, with little hands-on activity.

“As scrub gets older it starts to lose its interest for nightingales. They like dense ground vegetation and cover at that level, so at Grafham we clear the scrub down until it lays flat, but remaining attached to the base so it keeps growing. This keeps it nice and dense and really helps them.

“Gathering data from tagging is invaluable as it brings better knowledge of the birds’ exact migratory route and stopovers so we can discover what problems they are encountering along the way.”

The tags weigh just 1gram and scientists have carried out tests to ensure that they do not affect the welfare of the birds.