Lethal Aggression in Captive Monkeys.

Estabishing the features of lethal aggression and patterns of aggressive behavior in monkeys, as well as assessing the age and sex structure of aggressors and victims, are important for tracing the evolutionary roots of lethal aggression in humans and developing the measures to prevent its manifestations in monkeys held in captivity. The aim of the study was to characterize species-specific features of conspecific lethal aggression in captive macaques, baboons and guenons. The intra-group lethal aggression events were analyzed over a 10-year period in rhesus macaques (Macaca mulatta), crab-eating macaques (Macaca fascicularis), pig-tail macaques (Macaca nemestrina), green monkeys (Chlorocebus aethiops), hamadryas baboons (Papio hamadryas), and anubis baboons (Papio anubis), kept in social groups. Such events were found to occur in all the six monkey species studied. In groups consisting of adult males, the maximum frequency of occurrence of lethal aggression events was observed in the rhesus macaques, while the minimum in hamadryas baboons. Species-specific differences were found in the patterns of lethal aggression in conspecific family groups consisting of males, females, babies and juveniles. In hamadryas baboons, anubis baboons and pig-tail macaques, i.e., in species with a pronounced sexual dimorphism in body size and social status, the main form of lethal aggression in family groups was infanticide committed by a single sexually mature male. In rhesus monkeys, crab-eating macaques and green monkeys, i.e., the species characterized by a relatively mild sexual dimorphism in body size and social status, the prevailing form of lethal aggression in family groups was a coalitionary violence of females toward young and adult members of the same group. [ABSTRACT FROM AUTHOR]