Ospreys are amazing, one of the first birds my father got me interested in as he was a very keen birdwatcher. An ornithologist in Scotland a few years ago fitted osprey chicks with radio transmitters to track their journeys between Scotland and Africa. I think he does it every year actually. The birds are named by local school children. His website is amazing as shows maps of how far they'd moved overnight, height, distance, etc and he can get a visual picture from the satellite co-ordinates of where the birds fished when they stopped off to hunt and roost and people en route would try and get pics of them. It got me hooked and you build up a relationship with the bird but migration is fraught with problems and one of the females he was following sadly when she set off back to Africa after raising young disappeared shortly after leaving Scotland - her signal stopped. It was really sad, he never knew what happened to her. She was called Logie. Anyway, this is his website if you want a look:
By clicking on the individual names in the projects section and then the Summer 2010 bit you can find out how they're doing and their annual migrations as ospreys return to the same area/nest every year but not always to the same mate!