Monday, 17 September 2012

Oh no....not Cuckoos again!

I thought 'Tracking the Cuckoos' was interesting enough to continue with a look at what was learnt from the satellite tagging of five birds in England in 2011.

This is Clement, the bird I sponsored last year and who made his contribution to some big surprises brought about by the BTO 'Tracking Cuckoos Project'. Clement was the first to leave the UK on 5 June which was the first surprise being such an early date. By the end of June two others had also departed, and the last had left on 22 July representing five surprisingly early departures from the UK. But the surprises had only just begun and the different directions taken as they headed back to Africa were the next, with one bird flying due east across the North Sea to the Netherlands, two heading off south-easterly across the North Sea and Belgium, with two south across the English Channel to France.

But 'my' bird Clement pulled off one of the biggest surprise of all when he started to head west from the coast of France towards Spain. This bird - together with Lyster moving likewise a few weeks later - highlighted a brand new migration route and possible stopover point north of Madrid.

The crossing of the Sahara Desert is one of the major sources of mortality for migrants, but Clement and Lyster both minimised the distance of this crossing by migrating down the western edge of the desert in to Senegal and the Gambia and in doing so became the first British Cuckoos ever to be recorded in West Africa. Eventually all five tagged birds had reached at least as far as the Congo Rainforest by the end of November, but the three birds which took the more central route flew the lesser distance but had to endure a much longer 2,000km desert crossing. 

Although all five birds had been caught and tagged in the UK within 70km of each other, they had been separated by up to 3,600km at times on migration and by the end of December 2011 they were all in Congo, the first time all five birds had been in the same country since leaving the UK in June/July.

All truly amazing stuff and I reckon we should at some later time, take a look at events of these five Cuckoos on their return migration back to the UK, though sadly Clement went missing having last been heard of in Cameroon on 25 February 2012, becoming the first of these five amazing creatures to be assumed dead, otherwise the project far, so good.

David Cookson Images: Cuckoo  Cuckoo
Cuckoo. David Cookson.

Thanks for another brilliant juvenile Cuckoo image from DC. Much appreciated David, yes....Brilliant. 

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