Colony differences in auditory thresholds in the canary (Serinus canarius).

Adult canaries (Serinus canarius) from a closebred colony of the Belgian "Waterslager" strain were trained with operant techniques to respond to pure tones. A psychophysical tracking procedure was used to measure absolute auditory thresholds in quiet and in noise. Absolute thresholds in the middle- to high-frequency region of the audiogram were between 30 and 40 dB higher (4-5 standard deviations) than those typically reported for other song birds including canaries of other strains and Waterslagers tested some years ago from another colony. Thus the Millbrook colony of domestic canary--an oscine songbird which learns its vocalizations by reference to auditory information--shows unusually high absolute thresholds for pure tones.