All the five British cuckoos that are being tracked by Scientists from the British Trust for Ornithology, have now reached parts of Africa.

The Scientists have been tracking their migration routes using small satellite-tracking tags, which were attached to the birds like miniature backpacks. The birds started their journey in a breeding ground in East Anglia and are now scattered about 3,000km in Africa.

The satellite tags gets activated once every two days and stay on for a period of 10 hours. The devices send a radio signal informing their location to a satellite. The tracking team led by Dr Chris Hewson from the BTO track the birds from their headquarters in Thetford in eh UK.

"We can log on to their website and download the most recent messages from each of the tags and download that onto a map. So we can get an almost live picture of where the birds are," Dr Hewson.

Two of the cuckoos are in southern Chad, one is in northern Nigeria, the fourth is in Burkina Faso and the fifth has reached Morocco. The birds in Chad have crossed the Sahara desert and the scientist aim to find out about the environment the bird use to survive in the desert.