A CROSS-CHANNEL tracking project to help solve the mystery of where Irish cuckoos spend their winter months has begun. 

The Cuckoo Tracking Project is being undertaken by the National Parks and Wildlife Service (NPWS) in collaboration with the British Trust for Ornithology (BTO).

It will satellite track four Irish cuckoos – Torc, Cores, Carran and KP – in an attempt to understand whether they undertake a different migration strategy to their British counterparts in winter, and to try to explain their population decline. 

Three of the Irish cuckoos tagged are from Killarney National Park in Co Kerry, while the fourth is from Burren National Park in Co Clare.   

Sam Bayley, left, conservation ranger at NPWS and director of the Irish Cuckoo Tracking project, with Jamie Durrant, conservation ranger at NPWS, getting ready to release a Cuckoo at Burren National Park in Co Clare. Valerie O'Sullivan Valerie O'Sullivan

The BTO has tagged 100 British cuckoos since 2011, which has helped them to learn about the routes they take and some of the pressures they face whilst on migration.

Cuckoos reside in Ireland from April to early July, having spent the winter on the African continent. They are a unique bird in Ireland as they lay their eggs in other birds’ nests and have no involvement in raising their young.

According to the NPWS, there has been a decline in the number of cuckoos in Ireland, with breeding numbers down by 27% between 1968 and 2011 when the last national census was conducted. 

In the UK, this decline is 40%. Population trends show large declines across England and Wales, with increases in Scotland and relative stability in Ireland. 

A close up of one of the Cuckoos at Burren National Park in Co Clare. Valerie O'Sullivan Valerie O'Sullivan

The Ireland, the cuckoo has displayed a population shift northwards and westwards, similar to a number of other migrants that winter in Africa’s humid regions. However, not much is known about the potential causes and drivers of these declines.

“While the cuckoo has been well-studied during the breeding season, very little is known about the routes they take once they head off on migration or where in Africa they spend the winter months,” the NPWS said.

“If these areas of importance could be identified, then scientists would be able to better understand habitat pressures that affect losses of the cuckoo population.”

Minister of State for Heritage Malcolm Noonan said the project ushers in “a new era for bird monitoring” in Ireland.

“Cuckoos are fascinating creatures and the Irish population’s migration patterns are something of a mystery, so it will be very exciting to see the results of this innovative project over time,” he said.

Sam Bayley, left, director of the Irish Cuckoo Tracking project, holding a Meadow Pipit - one of the Cuckoos greatest nemesis, while Tom Stuart, BTO volunteer, holds the Cuckoo at Burren National Park in Co Clare. Valerie O'Sullivan Valerie O'Sullivan

“It will be fantastic to get a full picture of the movements of these birds at home, during their migration and when they hopefully return to our shores.”

Dr Chris Hewson, lead scientist with the BTO cuckoo project, said it’s exciting to see birds from Ireland tagged for the first time.

“We’re looking forward to learning for the first time about the migrations of these cuckoos from the western extremity of the species’ breeding range,” he said.

“These birds will help us to better understand the pressures they face, the reasons for the population declines they are undergoing and how we can help them to successfully complete their arduous migrations in the rapidly changing world we share.”

The four tagged cuckoos can be tracked on the BTO website, where they each have their own page.

A special project page will also be established on the NPWS’s website.