Call convergence within groups of female budgerigars (Melopsittacus undulatus)

The budgerigar (Melopsittacus undulatus) is a promising model species for t he study of adult vocal learning. To date, several studies have confirmed t he existence of vocal plasticity and, more importantly, rapid imitation of contact calls by adult male budgerigars. Vocal learning has not been invest igated in female budgerigars, however. Since one likely function of the con tact call is to denote group affiliation, we tested the hypothesis that fem ale budgerigars, when placed into groups, would develop a shared contact ca ll. We recorded the contact call repertoires of eight adult female budgerig ars that were unfamiliar with one another, then placed them into two groups . Each group was deprived of visual contact with other birds. Recording ses sions continued for the subsequent 8 wks, and behavioral observations were also conducted during this time. Within 4-7 wks, females in both groups con verged on a common call type. This rate of convergence is slower than that observed in prior experiments limited to male birds, and much slower than v ocal imitation by male budgerigars paired with females. Therefore, while ou r study documents vocal plasticity in adult female budgerigars, it also sug gests that female budgerigars learn new vocalizations more slowly than male s do.