Head-turn angles at peripheral stimulus positions.

For each owl and stimulus condition (39n = owl 39 normal, 39c = owl 39 ruffcut), the mean azimuthal head-turn angles±standard deviation (SD) at ±140° stimulus azimuth (azi) is given for the three stimulus elevations (ele). Responses to HRTFs of owl 39 ruffcut were highly significantly (Mann-Whitney test, p<0.001) smaller than responses to either individualized (respectively owl H's HRTFs in case of owl P) or owl 39 normal stimuli for any owl and elevation.