Development of Auditory Sensitivity in Barn Owls (Tyto furcata pratincola)

Abstract

The development of hearing in the juvenile barn owl was investigated using tones (500 Hz to 12 kHz) and clicks of different rates (5-90 Hz). Auditory evoked potentials (AEPs) of the auditory nerve were recorded using the auditory brainstem response (ABR). Barn owl hearing matured in a similar trend to other developing vertebrates, including kittens, budgerigars, chickens, and gerbils. The onset of hearing began sometime earlier than the second week post-hatch, and proceeded in a frequency-dependent manner. Adult-like thresholds were reached in a progression from low to high frequency, and sensitivity was mature by P60. These patterns were consistent with CAPs recorded from juvenile barn owls in Europe. ABRs for clicks presented at 5-60 Hz demonstrated increasing amplitudes and decreasing latencies as barn owl chicks aged, while ABRs for clicks presented at 90 Hz were barely distinguishable between adults and juveniles.