Fig. 6. Mean pitch angle of the tail (A) and neck (B) relative the long axis of the body of the birds (N=8) as a function of the position of the birds inside the obstacle course. Different symbols denote the different difficulty levels of the obstacle course. The legend describes these levels as the horizontal distance between adjacent barriers (cm) (Fig. 1). Vertical arrows denote the position of the barriers. The horizontal axis was normalized by dividing it by the distance between the two extreme barriers and shifting the horizontal position of the first barrier to zero. Error bars are ± s.d.