Anyone know what this is, I found a headless bird, kestrel, or a sparrowhawk maybe?
http://karlos.smugmug.com/photos/393286504_dP689-L.jpg
http://karlos.smugmug.com/photos/393286504_dP689-L.jpg
Check out the feet! Not raptor claws - should have been your best clue in the absence of a head
Had a look at the your other pictures - hope your thumb is better
But there are far more knowledgeable than me - so we will see.
Nope, never seen them do that - indeed it would be a very poor strategy to expend more energy than they need. Having been priviliged enough to fly many a raptor from the glove, I can attest to the fact they won't fly at all if not hungry - they will sit stil in a tree whilst digesting their meal. Ask any falconer and they will tell you if you don't ration food any bird of prey will simply refuse to fly as there is no imperative to do so.