University Honors

This research examines the impact of the reflector feathers on the sound perception of the Barred Owl (Strix varia). As in most owl species, the Barred Owl has a facial disk, a circular arrangement of fluffy feathers (auricular feathers) forming a concave disk-like shape, surrounded by a dense facial ruff. The facial ruff is composed of thin, stiff, and dark feathers called reflector feathers. The ruff extends behind the owlís ears and preaural flap, a movable skin flap in front of the ear canal. To research this, ten Barred Owl heads were tested with different conditions, manipulating head elevation, ear flap position, and the removal of different feather tracts. A speaker playing white noise was placed in front of the owl specimen, while small microphones placed in the ear canal recorded the sounds received. The collected audio data was analyzed to determine how reflector feathers influence the Barred Owlís hearing. Previous research on a distantly related species of owl, Barn Owl (Tyto alba), has shown that facial ruffs composed of reflector feathers acted as a ìsound collectorî, significantly amplifying sounds directly in front of the owl, especially those of higher frequencies (von Campenhausen, 2006). The results showed that although the Barn and Barred Owl were similarly impacted by the removal of reflector feathers, with heads without reflector feathers perceiving sounds at higher frequencies at louder amplitudes than owl heads tested with their reflector feathers removed, their ear asymmetry was shown to be different from one another.