Based on the hypothesis that, in Akodon azarae, polygyny operates through female defence, we studied inter-male aggression in order to test the following predictions: during the breeding period (1) resident males are more aggressive than intruder males in the presence of females (FP), and (2) aggressive behaviour is independent of male condition (resident or intruder) in the absence of females (FA). To test our predictions, we used the resident male behavioural response towards an intruder male in relation to FP or FA. We conducted 30 encounters in FP and 27 in FA in 0.79-m 2 round enclosures placed in the Espinal Reservation. Our results support the prediction that, in FP, the intensity of aggressive behaviour exhibited by males varied in relation to resident or intruder condition. Resident males showed high levels of aggression towards intruders, and intruders exhibited the greatest values of submissive behaviours with residents. In FA, the intensity of aggressive behaviour did not vary in relation to resident or intruder condition. Both resident and intruder males exhibited low aggressive behaviour and inter-male encounters resulted mainly in non interactive behaviours. Our results support the hypothesis that, in A. azarae, the polygynous mating system operates through female defence.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.