Cuckoos stay on course
With short hectic wing strokes that are hardly raised above the body, the flight of the cuckoo is not the height of elegance. Nevertheless, their wings carry them over 16,000 kilometres a year. Martin Wikelski from the Max Planck Institute for Ornithology in Radolfzell, Germany, together with an international team of scientists, has used satellite data for the first time to follow the cuckoos' migration from their breeding grounds in Denmark and southern Sweden to the wintering sites in Central Africa, and back again. Despite the enormous distances, the routes of the individual birds hardly differ from one another. Flight routes calculated with computer models based entirely on an inborn sense of orientation are far more variable. It seems therefore that cuckoos do not rely solely on an inborn compass-clock-navigation ability, but use additional orientation aids.