Behavioural Correlates of Social Dominance in Male Zebra Finches

Abstract

Illuminating the adaptive nature of animal behaviours is a major goal of evolutionary biology, and the fitness consequences for many behaviours have been well-documented. Animal personality research seeks to achieve this goal by first integrating multiple behaviours into a single ‘personality’ trait, but it has been argued that this approach offers no additional value to the traditional methods of assessing multiple, isolated behaviours as potential predictors of fitness. In this study, I measure seven behavioural traits in male zebra finches (Taeniopygia guttata) to determine the consistency of those behaviours within individuals and contexts, and to investigate how well these traits predict social dominance, measured as aggressive interactions between males, in a feeding context. This study was designed to compare directly with previous results from a study of female zebra finches that investigated the relationship between behaviour and social dominance from a personality perspective. I found that while the analysis of personality suggests that there is no association between behaviour and social dominance, the analysis of individual behaviours reveals that several behaviours significantly predict social dominance in males. Females similarly show no association between personality and social dominance when the latter is measured as aggressive interactions between females, but it is possible that evaluation of multiple, isolated behaviours would reveal a different pattern in females, as well. I conclude that the study of individual behavioural traits, rather than integrated personality traits, is probably more useful for evaluating the adaptive significance of behaviours, and provides results that are much easier to interpret and compare among different studies and species.