https://www.youtube.com/watch?v=WFrnR2XBCSM
It was an accident of this type:
https://www.youtube.com/watch?v=f0LEAoTyoA8 - Latvia osprey cam
https://www.youtube.com/watch?v=wmXN5OVZqSM. - Hellgate Montana osprey cam
1:00-1:21 The chick originally in the middle is pecking the chick originally on the right side. That chick turns towards the cam.
1:45-2:16 The chick that pecked another chick goes to the background.
2:17 The chick behind there turns it's tail away of the cam.
2:18 Immediately after that wind blows chick's tail up and pushes it towards the chick nearest to the cam. Wind gets it's way also under that chick's tail and pushes it up too. The chick whose tail was first pushed up roll's over but manages to get on it's feet again. Another chick makes a full roll or a somersault and drops out of the nest.
by hyypiö, good explanation on page 11 - > blown by the gusty winds
http://www.looduskalender.ee/forum/view ... &start=200