Duetting, Pair Bonding and Agonistic Display in Parakeet Pairs

I tested two models (pair bonding; coyness) of the relationship between duetting and pair bonding with behavioral and vocal data from captive canary-winged parakeet (Brotogeris v. versicolurus) mates before and after their pair formations. In all pair formations, pair establishment preceded or occurred simultaneously with well-coordinated, species-typical duets. There was no evidence of duet practise before pair initiation or improvement in duets during pair integration. Both models lead to the prediction that new pairs should duet more frequently early in their pairing compared to later. But duetting rates did not exhibit a peak early in the pair relationships. New pair duet rates increased relatively late (third to fourth week after pairing) in the pair history and did not show a decline over time. Affiliative interactions did not peak at the same time as duetting, as predicted by the pair-bonding model, nor did affiliative acts peak after a peak in duetting, as in the coyness model. Duetting rates of new pairs were not significantly different from those of older pairs. Thus, although duetting is a cooperative, intrapair interaction, there is no evidence that it promotes pair bonding in canary-winged parakeets. A significant, positive correlation was found between duets and agonistic acts against others. The pair formation data and this correlation between duetting and agonism against others suggest that there has been selection for rapid acquisition of duetting ability with a new partner. If parakeet pairs spent prolonged periods learning their duets, they could lose status within the group and the ability to present a coordinated, united front in the competition for resources. This may have been the selection pressure that led pairing in canary-winged parakeets to be accomplished without recourse to coy behavioral or vocal strategies.