Current social management practices contribute to reproductive failure in zoo-housed guenons

Abstract

Recent emphasis on reflecting natural behaviour and wild group composition in zoo-housed social animals has resulted in substantial improvement in captive breeding and welfare. We investigated studbook data for four guenon species housed in European zoos to assess the role of zoo management practices in the reproductive success of social species. We hypothesized that group dynamics reflecting wild living, including early social experience, would be associated with greater reproductive success. Our findings are presented in a standardized qualitative risk assessment with an additional certainty measure in the form of literature evidence. We found that greater reproductive success was associated with more potential breeding partners in L’Hoest’s, Roloway and Diana monkeys and with larger group sizes in all species studied here, providing support that mimicking wild group size, composition, and dynamics under captive conditions can improve reproductive success. Unexpectedly, greater reproductive success was associated with earlier first inter-facility transfers in female L’Hoest’s and Diana monkeys, and with more frequent inter-facility transfers in male L’Hoest’s and Diana monkeys. Furthermore, for male Diana monkeys and female and male L’Hoest’s monkeys, mothers with less reproductive and rearing experience tended to produce offspring that in turn had greater reproductive success, hinting at more complex and sex-differentiated mechanisms underlying sub-optimal reproduction in zoo guenons. Our findings highlight the importance of carrying out species-specific studies, and demonstrate that zoo management and husbandry practices can inadvertently impact reproductive success. We recommend that zoos holding guenons consider reducing the number of guenon species they hold in favour of increasing group size to improve reproductive success.