Cuckoo's dramatic decline tackled on Dartmoor
1 September 2013 Last updated at 00:03 BST
The call of the cuckoo is a sound that is fading from the British countryside as the bird's numbers plummet dramatically.
In the last 25 years England has lost over half its breeding cuckoos whilst in the south Devon lowlands, one of the bird's key breeding areas, numbers have dropped by as much as 80%.
On Dartmoor the British Trust for Ornithology is working with the National Park to satellite tag cuckoos to shed new light on what is going wrong.
Already they have found that cuckoos leave the UK much earlier than previously thought and birds from different regions of the UK take different routes to Africa, some more perilous than others.
Presenter Nick Baker visits Dartmoor to find out what is being done to try to help the birds.
Inside Out South West is broadcast on Monday, 2 September on BBC One at 19:30 BST and nationwide on the iPlayer for seven days thereafter.