Cuckoos are a fast declining species in our area, and also generally in Britain. Nobody really knows why. Probably most of us can remember hearing the Cuckoo in spring even if we didn’t see them (they can be remarkably elusive for such a large bird). Only birds passing through our area have been heard in the last few years (I did hear one calling from Mad Bess Wood the other evening – 27 May– but it was the first I had heard for two years). A satellite tracking programme has been set up by the British Trust for Ornithology (BTO) to help investigate the problem. Prior to this the only record of a Cuckoo in its winter quarters was from a ringed bird in the Congo. Now it seems that all the British birds eventually reach and winter in the Congo. However, they can take different routes, with some crossing the Sahara farther east. Curiously birds may use a different return route. The results show that birds return to the same locality to breed (one bird has been tracked for four years, so clearly the tracking device is no hindrance). Most unexpectedly, it has been found that 50% of Cuckoos leave the UK before the end of June, so many spend a very short part of their lives in this country.
Tracking cuckoos to Africa
Colin Bowlt- 29.5.15