Cuckoos from Sherwood Forest, the New Forest, Thetford Forest and Dartmoor have been fitted with satellite tags to help researchers understand the challenges these birds face as they make their incredible journeys.

The eight new birds join the four surviving individuals tagged in previous years, and BTO scientists will be watching all 12 closely as they move through Europe and Africa during the next couple of months.

Seven have already left the UK; four have moved to France, one is in northern Spain whilst others are in north-west Hungary and northern Italy. Some of the birds will stopover in southern Spain, to feed and fatten up before attempting the crossing of the Sahara Desert, whilst others will do the same in northern Italy and the Balkans, allowing researchers to compare the success of the western versus the eastern migration route with that of previous years. Each bird will make the desert crossing in one 2,000 mile non-stop flight.

What BTO scientists are very keen to learn is how the birds interact with a weather system called the Inter Tropical Convergence Zone (ITCZ) as they prepare to make their way back to Britain next spring. The drought-busting rains that this system brings to West Africa in early March may be vital to the success of onward migration from countries such as Sierra Leone, Ivory Coast and Ghana.

Dr Phil Atkinson, scientist on the project at the BTO said, “Five years into the project we know a lot about the migration routes our Cuckoos take to and from Africa but now we need to focus our attention on how the weather conditions along these routes might be affecting the timing of the migration. With the use of these amazing little backpacks we can watch these Cuckoos in near real-time as they move around the planet; what’s more, anyone else can watch them too as the positions automatically appear on the Cuckoo map on the BTO website. It is a very exciting time.”

He added, “The journey south and then back again is fraught with danger so we will be keeping everything crossed for these amazing birds.”

Anyone can follow and sponsor these 12 Cuckoos as they head south at www.bto.org/cuckoos