Improving stability and reproduction in rhesus colonies by manipulating sex ratio

 描述(申请人提供)：猕猴圈养繁殖群体中的一个常见问题是高接触率、攻击性和伤害率。尽管野生恒河猴也经常表现出攻击性，以此作为加强群体成员之间支配关系的一种手段，但管理圈养恒河猴的最佳实践表明，我们试图理解和减少攻击性。过去的研究表明，增加繁殖群体中非出生雄性的比例是一种很有前途的方法，可以显著改善圈养恒河猴群体的稳定性、福利和产量。这些非出生的成年男性，特别是地位较高的男性，在其群体成员之间的冲突中干预最频繁和最成功，导致攻击和创伤的发生率较低，并改善了社会稳定。拟议项目的主要目标是增加繁殖群体中非出生成年雄性的比例，并确定哪些因素对实现这一目标最关键。通过在将新的雄性群体引入大型繁殖群体之前、期间和之后收集广泛的行为数据，可以评估由此产生的性别比例对群体稳定性、慢性压力和生殖的长期影响。具体目标是：(1)确定预测雄性成功融入新繁育群体的能力的因素，包括比较不同的将新雄性引入群体的技术、雄性的特征(例如，个性、社会经验、冲突干预的成功)和繁殖群体的特征(例如，母系碎片化程度、行为模式、群体规模)；(2)确定不同引入技术的效果 通过创建攻击性和支配性等级网络，并通过测量头发样本中皮质醇的值作为研究阶段中群体成员感知的压力的代表，以及(3)评估性别比、群体稳定性、伤害率、压力和生殖成功之间的相互关系，来衡量群体稳定性的社会网络上的男性冲突干预成功。我们预测，随着群体中非出生成年男性比例的增加，群体稳定性措施将得到改善。这项研究将有助于提高恒河猴的福利和繁殖成功，作为动物资源，为生物医学和行为研究提供支持，为这项工作提供健康的动物模型。这项研究也响应了社会对促进和保护动物福利的期望。

 DESCRIPTION (provided by applicant): A common problem in captive breeding groups of rhesus macaques is high rates of contact aggression and wounding. Even though rhesus monkeys in the wild also show frequent aggression as a means of reinforcing dominance relations between group members, best practices in managing captive rhesus dictate that we attempt to understand and reduce aggression. Past research has shown that increasing the proportion of non-natal males in breeding groups is a promising method for significantly improving the group stability, welfare, and production in captive rhesus colonies. These non-natal adult males, particularly high ranking ones, intervene most frequently and most successfully in conflict among their group members, leading to lower rates of aggression and trauma and improved social stability. The primary goal of the proposed project is to increase the ratio of non-natal adult males in breeding groups, and to determine which factors are the most critical in achieving that goal. By collecting extensive behavioral data before, during, and after the introduction of new male cohorts to large breeding groups, the long-term effects of the resulting sex ratios on group stability, chronic stress, and reproduction can be assessed. The specific aims are: (1) to identify factors that predict a male's ability to successfully integrate nto a new breeding group, including comparing different techniques to introduce new males to a group, characteristics of the males (e.g., personality, social experience, success in conflict intervention), and breeding group characteristics (e.g., degree of matriline fragmentation, behavioral patterns, group size); (2) to determine the effects of different introduction techniques and male conflict intervention success on social network measures of group stability by creating aggression and dominance rank networks, and by measuring cortisol values in hair samples as a representation of perceived stress among group members across study phases; and (3) to evaluate interrelationships among sex ratio, group stability, wounding rates, stress, and reproductive success. We predict that as the proportion of non-natal adult males in groups increases, group stability measures will improve. This research will help to improve the welfare and breeding success of rhesus macaques held as an animal resource to support biomedical and behavioral research by providing healthy animal models for this work. This research is also responsive to the societal expectation for promoting and protecting animal welfare.