Lethal Aggression in Captive Monkeys

Abstract

Establishing the characteristics of monkey lethal aggression, assessing the age and sex of aggressors and victims, and the nature of the aggressors' actions seems necessary to identify the evolutionary roots of cases of human lethal aggression. In addition, the study of the features of lethal aggression can be considered as a condition for the development of measures aimed at preventing its manifestations in captive monkeys. The aim of the study is to study the species-specific features of lethal aggression in captive macaques, baboons and guenons. An analysis was made of cases of intra-group lethal aggression that occurred over a 10-year period in Rhesus macaques (Macaca mulatta), Crab-eathing macaques (Macaca fascicularis), Pig-tail macaques (Macaca nemestrina), Green monkeys (Chlorocebus aethiops), Hamadryas baboons (Papio hamadryas), Anubis baboons (Papio anubis) kept by social groups. It has been established that cases of lethal aggression are observed in all 6 studied species of monkeys. It was shown that in groups consisting of adult males, the highest frequency of cases of lethal aggression was noted in Rhesus macaques, and the lowest in Hamadryas baboons. Species-specific differences were found in the nature of lethal aggression in monkey family groups consisting of males, females, infants, and adolescents. It has been established that in Hamadryas baboons, Anubis baboons and Pig-tail macaques, that is, in species with pronounced sexual dimorphism in body size and social status, the main form of lethal aggression in family groups is infanticide committed by a single sexually mature male. In Rhesus monkeys, Crab-eathing macaques and Green monkeys, that is, those species that are characterized by relatively mild sexual dimorphism in body size and social status, the predominant form of lethal aggression in family groups is the collective actions of females aimed at young and adult members of the group.