This site takes you into the world where technology is trying to understand animal migration by using tags and a sophisticated satellite system to follow routes taken by animals. Up until now tags have often been very heavy, or at least too heavy for a lot of tiny birds that make huge migrations such as the cuckoo. Other tracking has used daylight length so that during the equinox when birds ofter migrate they are inefficient. Papers have been written on very incomplete evidence such as 4 individuals. The Icarus project will deliver enormous amounts of data which should enable us to understand these animal movements better.