Integrity of and damage to wings, feather vanes and serrations in barn owls.

The silent flight of owls is well known. It has served as role model for the designs of new airplane wings and ventilators. One of the structural features that underlies silent flight is the serrated leading edge of the wing that is mainly formed by the tenth primary flight feather (P10).

Sound localization in barn owls studied with manipulated head-related transfer functions: beyond broadband interaural time and level differences.

Interaural time and level differences are important cues for sound localization. We wondered whether the broadband information contained in these two cues could fully explain the behavior of barn owls and responses of midbrain neurons in these birds. To tackle this problem, we developed a novel approach based on head-related transfer functions.

Size discrimination in barn owls as compared to humans.

We tested how well barn owls can discriminate objects of different sizes. This ability may be important for the owls when catching prey. We performed a quantitative experiment in the laboratory and trained owls in a task in which the owls had to discriminate whether two rhombi presented simultaneously on a computer monitor were of the same or of different sizes.

Spatial contrast sensitivity and grating acuity of barn owls.

The eyes of barn owls (Tyto alba pratincola) display very little aberrations, and have thus excellent optical quality. In a series of behavioral experiments, we tested whether this presumably beneficial feature is also reflected at a perceptual level in this species. As fundamental indicators for visual performance, the spatial contrast sensitivity function (CSF) and grating acuity were measured in two barn owls with psychophysical techniques.