Tim writes: I thought this was quite a dramatic flight shot of a Cuckoo flying past like a paper dart. I took this one in the Peak District when there were two males chasing each other on the moors.
Cuckoos are suffering a massive population nosedive in Britain, but particularly those in England. All British Cuckoos winter in the same area of central Africa but they don’t all take the same route. 42 Cuckoos from nine breeding areas were satellite tagged and bizarrely most of the English Cuckoos take a different migratory route to most of the Cuckoos from Wales and Scotland. Most English birds took the shorter route via Spain with others taking a longer route via Italy or the Balkans. Despite the route via Spain being shorter, the proportion of birds using it strongly correlated with the population decline. It seems that most of the mortality occurs before the Cuckoos even reach Africa. West flying birds spend more time fattening up in Britain before migrating. Big caterpillars are the main food of Cuckoos and the decline in these is more pronounced on the western route. The decline in big caterpillars, coupled with the increased frequency of droughts in Spain are the suspected causes of the rapid decline in Cuckoos.