Abstract # 38:

Scheduled for Thursday, August 17, 2006 03:00 PM-03:15 PM: Session 5 (Regency East #2) Oral Presentation

Cross-sectional study of the behavioral development of young male chimpanzees in twenty zoos

M. A. Bloomsmith1,2, S. R. Ross3, T. Bettinger4, A. W. Clay2 and U. Anderson2
1Yerkes National Primate Research Center, 954 Gatewood Road, Atlanta, GA 30329, USA, 2Georgia Tech Center for Conservation and Behavior, 3Lester E. Fisher Center for the Study and Conservation of Apes, Lincoln Park Zoo, 4Disney's Animal Kingdom
     Despite the benefits of housing captive chimpanzees in complex, species-typical social groupings, such housing has led to the difficult issue of managing young males during their adolescent years when their aggressive behavior typically escalates. A collaborative, cross-sectional research project was conducted at 20 zoos to describe behavioral, hormonal and wounding incidence information during male chimpanzee development. An ethogram with 14 behavioral categories was used to collect 1556 hours of observational data on 37 male chimpanzees ranging from 5 to 18 years old. Data collected by an instantaneous method indicated that subjects devoted very small percentages of time (<1%) to aggression, submission or aggressive displaying, more time was spent engaged in prosocial behavior (8% grooming and play), and the vast majority of their time was spent in nonsocial activities (>70% inactive, manipulate objects/environment, locomote, self-groom). Additional all-occurrence data revealed subjects were involved in attacks less than once every 10 hours and in threats less than once every 5 hours. Pearson correlations indicated rates of submissive behavior increased as the subjects matured, but aggression, displaying, and anxiety-related behaviors showed no relationship with age. Findings from this study will provide chimpanzee colony managers with concrete information on the frequency, intensity and duration of agonism to be expected during the period of maturation for young male chimpanzees, and a “norm” against which individual animals can be evaluated.