Why do winners keep winning? (24579) (#814)
Prior contest experience can influence the outcome of future contests. For example, an animal that loses a contest might be more likely to lose his next bout while a winner might be more likely to continue winning (winner-loser effects). However, the effects of prior contest experience may be highly dependent on the behaviors used during contests and whether they involved non-contact signalling or escalated to physical contact and biting. Where contests are resolved using ritualized displays, contest initiation—an animal’s readiness to engage, may be an important predictor of contest outcome because initiators appear more aggressive to their opponents. Conversely, in escalated contests, an individual’s willingness to engage and bite his opponent may be a more important predictor of contest outcome. We asked whether contest outcome in male Eastern Water Skinks (Eulamprus quoyii) is determined by previous contest experience and whether this is influenced by an individual’s behaviour and level of escalation. We staged contests using size-matched pairs in neutral arenas. We recorded which individual initiated the contest, the number of times an individual bit his opponent and whether the contest escalated or not. We predicted a priori that: 1.) winning increases the probability of initiating a contest and whether a male will escalate a contest; 2.) contest initiation will predict contest outcome in only non-escalated contests; and 3.) the total number of bites by a male will be an important predictor of contest outcome in only escalated contests. Our results supported our predictions and highlight the importance of contest-specific behavior in accounting for winner-loser effects.