Figure 3.

The learning (recovery) curve for 4 budgerigars (mean +/− SD) tested on a call classification task after a 1-month delay which began after a 10-day course of kanamycin (closed circles). The performance of these birds is compared with the learning curve for 4 normal budgerigars tested after a 1 month delay with no kanamycin treatment (○). Untreated budgerigars reach criterion performance again after one session while kanamycin-treated budgerigars were delayed in their reacquisition of classification of familiar calls.