Social organization of captive black howler monkeys (Alouatta caraya): “Social competition” and the use of non-damaging behavior

Abstract

This paper assesses non-damaging social behaviors as tactics of interindividual competition by a descriptive analysis of dominance, copulation, grooming and play in a captive group of black howler monkeys (Alouatta caraya). The social behavior of this species has not previously been documented in the literature, and it is reported that rank is negatively related to age for adult females, similar to other species ofAlouatta. The significance of non-damaging social behavior to howler monkeys may relate to their folivorous habits and consequently high metabolic costs which increase chances for “aggressive neglect.” With respect to the form of motor patterns, low probabilities of escalation from less aggressive to more aggressive behavior (e.g., from grooming to pairwise supplantation) are associated with “ritualization” of signals, and, apparently, with greater reliability of these signals. It is suggested that non-damaging social behaviors may be costly to reproduction through the depletion of limited time resources, may function generally in the resolution of interindividual conflicts of interest and may be particularly important to the behavioral repertoires of social subordinates.