INNER-EAR ABNORMALITIES AND THEIR FUNCTIONAL CONSEQUENCES IN BELGIAN WATERSLAGER CANARIES (SERINUS-CANARIUS)

Recent reports of elevated auditory thresholds in canaries of the Belg ian Waterslager strain have shown that this strain has an inherited au ditory deficit in which absolute auditory thresholds at high frequenci es (i.e. above 2.0 kHz) are as much as 40 dB less sensitive than the t hresholds of mixed-breed canaries and those of other strains. The meas urement of CAP audiograms showed that the hearing deficit is already p resent at the level of the auditory nerve (Gleich and Dooling, 1992). Here we show gross abnormalities in the anatomy of the basilar papilla of Belgian Waterslager canaries at the level of the hair cell. The ex tent of these abnormalities was correlated with the amount of hearing deficit as measured behaviorally.