Bushmeat trade consequences predict higher anxiety, restraint, and dominance in chimpanzees

Abstract

More data are needed for a better understanding of the long‐term influence of wider and combined stressful events in chimpanzee personality development. We evaluated the effects of bushmeat trade outcomes on the personality development in 84 African sanctuary chimpanzees. The chimpanzees presented different backgrounds regarding maternal care, social exposure, and abuse. We evaluated personality traits in chimpanzees using the Cattell 16PF personality questionnaire, the first application of this questionnaire in this species. We found that chimpanzees were rated as higher in anxiety after long social deprivation during infancy and juvenility, and if high human exposure was experienced. Mother‐reared chimpanzees were rated as lower in restraint than hand‐reared chimpanzees. Finally, mother‐reared chimpanzees were rated as less dominant than hand‐reared chimpanzees and rated higher when they had experienced severe mistreatment. Results suggest a wide range of possible stressful events could be potentially shaping rescued chimpanzees’ personality and demonstrating the detrimental outcomes and consequences of the bushmeat and pet trade.

Early life experience and alterations of group composition shape the social grooming networks of former pet and entertainment chimpanzees (Pan troglodytes)

“…Furthermore, former pet and entertainment chimpanzees, living in accredited zoos and sanctuaries, who were mainly exposed to humans in infancy showed lower levels of extraversion and exhibited deficiencies in social bonding [38]. Finally, Ortín et al [39] demonstrated that the personality development of chimpanzees who were rescued from bushmeat and pet trade was affected by these early life experiences, and resulted in higher ratings in the factors anxiety, restraint and dominance.…”

Personality, cognition and behavior in chimpanzees: a new approach based on Eysenck’s model

“…Cognitive tasks and experimental design are detailed in Riba (2016). In brief, the tasks consisted of 11 puzzle boxes made of methacrylate which included different components such as doors, wooden bars, slides and tubes (see Fig.…”

“…The original purpose of the study by Riba (2016) was to investigate the occurrence of social learning. Therefore, before being tested, subjects received three different types of information on how to solve the puzzle boxes: (1) Control (no information), (2) No social information (the subject only saw the end state of the task, without seeing any of the actions necessary to solve it), and (3) Social information (the subject saw both the actions of the demonstrator and the end state of the task).…”

“…The dashed lines depict the models, which have been back-transformed from the logodds ratio scale (black for females, grey for males). Full-size DOI: 10.7717/peerj.9707/ fig-4 with some of them having been exposed to traumatic past experiences which most likely shaped their personality (Ortín et al, 2019) and their behavior (Crailsheim et al, 2020).…”

Primate Orphans

“…Similar to the studies reviewed earlier, the conditions under which the chimpanzees in these sanctuaries are reared by foster mothers have an effect on their behavior later in life. For example, in a recent and novel study, Ortín et al (2019) evaluated the effects of bushmeat trade outcomes on the personality development of African sanctuary chimpanzees. Mother-reared chimpanzees were rated as lower in restraint than hand-reared chimpanzees.…”