Is the parallel walk between competing male fallow deer, Dama dama, a lateral display of individual quality?

During competitive encounters protagonists are expected to use signals of individual quality particularly if there is a risk of injury or death. Lateral presentation of body profile, by which information regarding phenotypic characteristics associated with individual quality are displayed, may represent such a strategy. During aggressive interactions, male fallow deer frequently engage in parallel walking which is assumed to represent a mutual display of quality, as mediated by exposure of the maximal profile of the body or antlers. We examined the context and role of the parallel walk during competitive encounters to investigate whether there was evidence that dyads of competing males were assessing differences in phenotypic characteristics. There was no evidence to support the hypotheses that the parallel walk is a lateral display of body size or weaponry or that its use is associated with a reduced level of escalated or risky behaviours during fighting. Total time spent fighting was not shorter when a parallel walk was present than when there was no parallel walk. The parallel walk was highly associated with fighting and it was more likely to be initiated by the subsequent loser. Furthermore, parallel walking frequently followed bouts of fighting and as such may represent a strategy that permits an animal the opportunity to decide whether to continue fighting. Parallel walking was also associated with a failure to resolve contests in favour of one animal indicating that it may be a means of withdrawing from further fighting without incurring a loss in dominance status. (C) 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.