Speaker
Description
The evolution of vocal flexibility has mainly been studied across species. Much less focus has been on which variables create differences between individuals. To address this gap, we studied monk parakeets (Myiopsitta monachus) as model species and tested how socio-ecological variables affect the vocal flexibility in an open-ended vocal production learner with socially complex nesting and foraging strategies. We collected data on sex, age, nesting location, four types of social network, relatedness and vocalisations for 337 individuals across two years. Using Bayesian multilevel models, we found that contact call diversity was high across most individuals and increased with age and in larger groups. We also found that contact calls were less similar between closely associated individuals, suggesting an active process to sound unique. Finally, we found that repertoire diversity increased with group size and was higher for females. Our results support the notion that contact calls serve multiple functions in monk parakeets and do not only contain a stereotyped signal of identity. Our results furthermore suggest that repertoires are socially learned and that more social individuals learn to use a more diverse repertoire.
