Hobby - Training Day part 1 (Falco subbuteo)

The first of a couple of several shots I managed whilst observing a pair of Hobby's plus their offspring, out on a 'training day'. I expect that the behaviour has been observed many times, but it's nice to capture it on Camera.
The parent birds have a wonderful routine to teach their offspring aerial agility and to catch prey.
The 'training' starts with one parent catching a dragonfly and then calling it's offspring with an 'eep-eep-eep-eep-eep'. Initialy the juvenile comes to the adult and is allowed the food 'beak to beak', this progresses to foot to beak (as the photo shows) and then on to foot to foot. The last bit of training involves the adult dropping the disabled dragonfly and the youngster has to then catch it's dinner in mid air.
Fascinating to watch.
I would appreciate anybody forwarding me web links that expand on this part of Hobby behavior.
Appologies for the poor quality shots, but the events happen in less than a second and it aint easy to capture.