A project which has been tracking cuckoos by satellite has provided conservationists with valuable information on the migratory patterns of the birds.

Eastern Daily Press: A Broads cuckoo with a satellite tracking tag attached. Picture: Courtesy Andrea KellyA Broads cuckoo with a satellite tracking tag attached. Picture: Courtesy Andrea Kelly (Image: Archant)

Broads Authority senior ecologist Andrea Kelly said the British Trust for Ornithology run project is going some way to answering questions why UK has lost over half of its cuckoos in the past 20 years.

The Broads Authority is one of many partners in the project and since it became involved in 2013, several Broads cuckoos have been tracked.

Sadly many have perished on their journey to Africa.

'This year we tagged a bird named Carlton as he was tagged at Carlton Marshes, but no signal has been received for some time,' said Ms Kelly. 'It's possible there was a malfunction with the tag or he has perished on the way.

Eastern Daily Press: A mist net used to catch cuckoos. Picture: Courtesy Andrea KellyA mist net used to catch cuckoos. Picture: Courtesy Andrea Kelly (Image: Archant)

'We have tagged birds in the past from the area that have made it to Africa and back so have had mixed success with birds from this region.'

The cuckoos, usually male, are identified by Broads Rangers. Ms Kelly then gets the necessary permission with landowners and helps the BTO and their volunteers to set up mist nets, call in the cuckoos by playing female cuckoo calls, catch the cuckoos and attach satellite tracking devices.

'The technology has given us live feed of the birds on their migrations,' she said. 'We have learned vital information regarding the routes they take and some of the difficulties they face during migration including the changing climate and how they respond to that.'

The information allows scientists and conservationists to look at ways to try and save cuckoos.

Eastern Daily Press: Female cuckoo calls are used to to lure males. Picture: Courtesy Andrea Kelly.Female cuckoo calls are used to to lure males. Picture: Courtesy Andrea Kelly. (Image: Archant)

'For instance one of the things being looked at is how the birds use the network of National Parks through Europe and across the globe,' said Ms Kelly. 'This information is then used by international working groups who can look at whether the space for nature reserves and National Parks is sufficient to retain the populations of birds.'

The BTO said there was still more to discover. Questions needing answers include how dependent cuckoos are on, and how much their migration is linked, to drought-busting rains of the weather frontal system known as the Inter Tropical Convergence Zone (ITCZ) as they move out of the Congo rainforest and head back to the UK via West Africa.

The Broads cuckoos

Nine Broads cuckoos have been tagged as part of the project.

2013: Nelson (named by EDP public appeal) failed to complete his migration to wintering grounds. Three other Broads Cuckoos were tagged alongside Nelson, including Derek who completed two and a half migration cycles before he was lost in Central Mali in August 2015.

2014: Gowk, named after cuckoo in a children's book, was lost on the southward migration in Spain in July 2014. Skinner made it to wintering grounds, but failed to return to the UK. Ken is also believed to have perished.

2016: '161322' tagged on the Chet and not named. Lost on the southward migration in August 2016 in Western Sahara and is presumed dead.

2017: Named after the Carlton Marshes, the last location received from Carlton's tag showed he was alive and well but nothing has been heard since. Hopes remain that he may turn up.

Keeping track

Cuckoos in the UK are under threat from population growth of humans and habitat change.

The dove-sized birds arrive in the country in the spring to breed. In early June the adults begin to leave and the young birds head south later too.

There are two routes most follow on their journey of at least 4,000 miles to the Democratic Republic of Congo in Africa.

Some fly south and west over Spain and Morocco, others go east over Italy and the Balkan countries.

On their return to Europe all the tracked cuckoos take the same route across West Africa.

This is probably to take advantage of food available at that time due to the heavy rainfall and insects breeding.

Broads Authority senior ecologist Andrea Kelly said it was important to save cuckoos as they were a part of the UK's history.

The cuckoos can be tracked at www.bto.org/science/migration/tracking-studies/cuckoo-tracking.