London: Five cuckoos which left Britain in June have now reached Africa, making a journey of almost 5,000 kilometres in less than three months, scientists who fitted
the birds with tiny satellite-tracking tags have claimed.
Researchers from the British Trust for Ornithology, who wanted to track the migration routes of the birds, caught five cuckoos and tagged them with GPS trackers in tiny backpacks.
Having started their journeys from the same breeding ground in East Anglia in June, the birds have now reached Africa and distributed across 3,000km of the continent, the
Their tags automatically switch on once every two days for 10 hours and send off a radio signal revealing their whereabouts, which is picked up by a satellite.
The cuckoo-tracking team, led by the BTO`s Chris Hewson, is able to follow the birds from the comfort of the trust`s headquarters in Thetford.
"We can log on to their website and download the most recent messages from each of the tags and download that onto a map," Dr Hewson explained. "So we can get an almost live
picture of where the birds are."
Four of the birds have already crossed the Sahara; two are in southern Chad, one is in northern Nigeria and the fourth one is in Burkina Faso. One cuckoo is lagging slightly
behind the rest and has made it as far as Morocco.
"He was last seen about 20km outside Casablanca," said Dr Hewson. "The bird that has travelled furthest, Chris, has already flown almost 5,000km to Chad. We`re expecting him to go further than that -- possibly as far as 6-7,000km."
Crossing the Sahara is one of the major sources of death for many migrants, so the team is relieved that almost all the birds have made it safely across the desert.
The team wants to find out what environments the birds rely on and where they stop off to feed along the way.
"Migratory birds don`t just have a breeding area and a wintering area, they also have staging posts where they spend different amounts of time," said Dr Hewson.
"Because Britain and Europe as a whole is getting warmer, they need to get back earlier and earlier to their breeding grounds.
"If we don`t know exactly where they are, we won`t know where the bottlenecks are that might be preventing the cuckoos from getting back to Brtain.
"So we`re particularly interested in where the birds are fattening up before the final journey to Britain."
Cuckoos are one of several migrant species declining in Britain. According to a 2010 survey by the Royal Society for the Protection of Birds (RSPB), of the 10 UK birds which have declined the most since 1995, eight are summer migrants, including the cuckoo, turtle dove, yellow wagtail and nightingale.