Table 1.
Definition of aggression scores of male fowl in response to the presentation of a manually presented intruder.
Table 2.
Correlations among behavioural responses of male fowl in a novel arena test, startle test and aggression score obtained during the initial part of a duel.
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<Sub, white column). When aggression scores differed between the two males of a pair, showing higher levels of aggression during the initial part of the duel was associated with winning it (12 cases vs 1 case).
Table 3.
Linear mixed-model analysis of aggression scores shown by male fowl towards a manually presented intruder.