Auditory brainstem responses and auditory thresholds in woodpeckers.

Auditory sensitivity in three species of woodpeckers was estimated using the auditory brainstem response (ABR), a measure of the summed electrical activity of auditory neurons. For all species, the ABR waveform showed at least two, and sometimes three prominent peaks occurring within 10 ms of stimulus onset. Also ABR peak amplitude increased and latency decreased as a function of increasing sound pressure levels. Results showed no significant differences in overall auditory abilities between the three species of woodpeckers. The average ABR audiogram showed that woodpeckers have lowest thresholds between 1.5 and 5.7 kHz. The shape of the average woodpecker ABR audiogram was similar to the shape of the ABR-measured audiograms of other small birds at most frequencies, but at the highest frequency data suggest that woodpecker thresholds may be lower than those of domesticated birds, while similar to those of wild birds.