Wasnt there a study done on this? i remember reading somewhere about an experiment and if i remember correctly it was a coopers, the jist of the experiment was that the after a while they realised the bird had caught loads but the wing beats she had done with each chase was fantastically low, a really silly number.If i remember it i will let you know.
Anyway, i stand by what i say, high jumps bring them on leaps and bounds and are great when you havent got a chance to fly _work, weather etc, plus with gosses, i use weights too.