Animal Science Department, Biomedical Primate Research Centre, Rijswijk, The Netherlands.
Animal Ecology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
PLoS One. 2019 Jul 17;14(7):e0219972. doi: 10.1371/journal.pone.0219972. eCollection 2019.
The entrance of new males into non-human primate groups bears high social risk, yet migration is necessary to prevent inbreeding. Males are not always accepted in their new group. In the wild, males may increase the likelihood of successful group entry by choosing a new group based on their own and the group's characteristics. Understanding whether these characteristics also determine a male's ability to enter captive groups is crucial to improve introduction management. This study aims to identify which factors determine male introduction success (i.e. male stays in the group for at least 4 weeks) and long-term stability (i.e. the male does not cause considerable behavioural problems after success) after male introductions in captive groups of rhesus macaques (Macaca mulatta), creating one-male groups. We studied 64 male introductions at the breeding colony of the Biomedical Primate Research Centre in Rijswijk, The Netherlands. 49 (77%) introductions were successful, with the male obtaining a long-term stable social position in the group in 38 (59%) introductions. Introductions of males that reached at least prime age, into groups with more adult females, but without pregnant females were most successful. Moreover, long-term stability was highest when males were heavier, were at least 3.5 years old when they were first removed from their natal group, and groups had few matrilines and no pregnant females were present. Males should be introduced at the time they would naturally immigrate, when they are strongest. Moreover, groups should consist of few large matrilines, as observed in the wild, with philoatric females and males that are removed at natural age. Our study highlights the importance of composing naturalistic groups and mimicking natural migration patterns to maintain long-term stable breeding groups in captivity.
新雄性进入非人类灵长类群体带来了很高的社会风险，但为了防止近亲繁殖，迁移是必要的。雄性并不总是被它们的新群体所接受。在野外，雄性可能会根据自己和群体的特征选择一个新的群体，从而增加成功进入群体的可能性。了解这些特征是否也决定了雄性进入圈养群体的能力，对于改善引入管理至关重要。本研究旨在确定哪些因素决定了雄性引入后的成功（即雄性在群体中至少停留 4 周）和长期稳定性（即雄性在成功后不会引起相当大的行为问题），即在圈养的恒河猴（Macaca mulatta）群体中创建一雄群体。我们研究了荷兰里兹维克生物医学灵长类动物研究中心繁殖群体中的 64 次雄性引入。49 次（77%）引入是成功的，在 38 次（59%）引入中，雄性获得了长期稳定的社会地位。引入至少达到最佳年龄的雄性，进入成年雌性较多但没有怀孕雌性的群体是最成功的。此外，当雄性体重较重、首次从出生地群体中移除时至少 3.5 岁且群体中的母系较少且没有怀孕雌性时，长期稳定性最高。雄性应该在其自然移民的时间被引入，也就是它们最强壮的时候。此外，群体应该由较少的大型母系组成，就像在野外观察到的那样，要有友爱雌性和自然年龄移除的雄性。我们的研究强调了组成自然群体和模仿自然迁移模式的重要性，以维持圈养中长期稳定的繁殖群体。
