AGE-RELATED DIFFERENCES IN PLAYFIGHTING STRATEGIES OF CAPTIVE MALE RED-NECKED WALLABIES (MACROPUS-RUFOGRISEUS-BANKSIANUS)

Age-related differences in the playfighting strategy of captive male r ed-necked wallabies Macropus rufogriseus banksianus was examined. Our purpose was to determine whether wallabies adjusted their play in resp onse to their partner's age and, if so, how. The way in which a wallab y played was dependent on the relative age of its partner, and this pa ttern tended to be the same regardless of whether it was the initiator or reactor of the interaction. If a wallaby's partner was younger tha n Itself it adopted a defensive strategy in which it self-handicapped by standing flat-footed, Pawing rather than Sparring, and by not using its full strength. Its greater rate of Shaking suggests that this act may function as an appeasement signal in play. Furthermore, it was hi ghly tolerant of the tactics used by its younger partner and took the more active role in prolonging interactions. If, on the other hand, it s partner was older than itself, it adopted an offensive strategy invo lving vigorous Sparring, increased time in the High-stance posture and a greater percentage of bouts that were of high intensity. Indeed, it played with even more vigour than when it playfought with wallabies o f the same age as itself. Differences in the play of same-aged partner s were in the non-fighting components of play, while those of differen tly-aged partners were in the fighting components. Play between same-a ged partners, however, tended to be more stable and more competitive t han that between partners of differing age. These results are discusse d with emphasis on the compromises made in order for play to occur and the potential benefits to each partner of play in mixed-age class enc ounters. We briefly consider the implications of self-handicapping in the categorization of macropodid fights as play or aggression.