Personality predicts social dominance in male domestic fowl

Abstract

Individuals in social species commonly form dominance relationships, where dominant individuals enjoy greater access to resources compared to subordinates. A range of factors such as sex, age, body size and prior experiences has to varying degrees been observed to affect the social status an individual obtains. Recent work on animal personality (i.e. consistent variation in behavioural responses of individuals) demonstrates that personality can co-vary with social status, suggesting that also behavioural variation can play an important role in establishment of status. We investigated whether personality could predict the outcome of duels between pairs of morphologically matched male domestic fowl (Gallus gallus domesticus), a species where individuals readily form social hierarchies. We found that males that more quickly explored a novel arena, or remained vigilant for a longer period following the playback of a warning call were more likely to obtain a dominant position. These traits were uncorrelated to each other and were also uncorrelated to aggression during the initial part of the dominance-determining duel. Our results indicate that several behavioural traits independently play a role in the establishment of social status, which in turn can have implications for the reproductive success of different personality types.

Figure 1. Behavioural responses in behavioural assays of future dominant and subordinate male fowl.

Males that later became dominant (filled dots) were (a) more explorative compared to males that later became subordinate (open dots, Exploration score is presented as SD units, see text for further explanation). There was no difference in (b) the number of crows uttered or (c) general vigilance in the novel arena test between future dominant and subdominant males. Future dominant males (d) remained vigilant for a longer period of time after a startle (a playback of conspecific warning call). Mean values ± SE are given. *p<0.05.

Figure 2. The distribution of differences in aggression score of male fowl in duels.

The winning, dominant male either had a higher aggression score compared to the losing, subordinate male (Dom>Sub, black column), the same aggression score (Dom = Sub, grey column) or a lower score (Dom