CUES OF OWNERSHIP IN LONG-TAILED MACAQUES, MACACA-FASCICULARIS

This experimental study of long-tailed macques explores the cues that induce a dominant animal to 'respect' object ownership in a subordinate. The object was a plastic tube filled with raisins. Owner-object proximity and the demonstrated ability of the owner to carry the object were indispensable for respect by a rival. Owner-induced movements in an object were not sufficient, to induce respect in the absence of proximity. The importance of continual inspection of the object by the owner was suggested by qualitative observations, but not substantiated in an experiment. In value asymmetry tests each opponent responded to his own but not to the other's satiation. Among adult females and juveniles, both robbing and tolerance occurred most frequently between mothers and offspring. Among males, there was no kin bias, but rivals preferentially robbed the older of two rivals. Rivals appeared, to interact preferentially with owners on the basis of their availability (i.e. proximity). When draglines of different lengths were attached to the food object, rivals were more reluctant to rob owners when the line was shorter. Data on screaming are consistent with the interpretation that the rival is more likely to be, attacked by third parties if he is close to a screaming owner. The possibility of third party interference can also explain why individual rivals responded differently to the same dragline lengths. The cost of such interference to the rival appears to be the likely ultimate cause of respect for ownership. © 1991 The Association for the Study of Animal Behaviour.