Social Behavior of Black-Handed Spider Monkeys (Ateles geoffroyi) Reared as Home Pets

Abstract

We studied the interactions between and within sexes of 7 molar categories of behavior—aggression, submission, avoid-retreat, social grooming, together, social play, and sexual interest—in a newly formed captive group of spider monkeys (Ateles geoffroyi) reared as pets and unacquainted with each other. Free-ranging Ateles geoffroyi show a characteristic sex-determined patterning of intragroup social interactions and relationships: males are more affiliative with males, and females are more solitary and more prone to be attacked by males. Our rationale, using socially handicapped subjects, was to test whether the monkeys were able to develop species-typical social relationships and constitute a cohesive group. We studied the group of 8 males and 6 females in an outdoor cage throughout 31 weeks, starting 1 week after the formation of the group. Their rate of interactions is not much different from those reported for natural groups. The patterning of interactions for almost all behaviors is similar to that which has been observed in wild groups. Our findings suggest that spider monkeys, despite unnatural nurturing, follow an innate species specific motivational script in the patterning of their interactions.