The effect of social and environmental manipulations on the vocal response rate of budgerigars ( Melopsittacus undulatus )

The budgerigar (parakeet) exhibits complex social interactions and relationships. This project investigates the budgerigar “contact call” that is used for both local and distance social cohesion. It is hypothesized that budgerigar vocal response rates will vary with the social “distance” of the caller (e.g., mates greater than conspecific strangers) and that overall rates will increase as the background acoustic environment becomes more complex and naturally rich. To test these hypotheses, vocal response rates of budgerigars were measured to four groups of recorded contact calls, within four acoustic environmental contexts. Three mated pairs were subjects. The results showed huge individual differences. Overall, males responded significantly more than females. There was a trend toward greater responses to mates than self, flockmates, or strangers. There were a large and significant response increases during a familiar flock background and significant decreases during silence. The response vocalizations themselves were analyzed for possible patterns to the different auditory contexts. The results are consistent with a hypothesis of social facilitation, although the individual differences pose a curious problem that a larger sample size may help elucidate. [Work supported by NIH/NIDCD 5R01DC000198 and 2P30DC004664.]