灵长类雌性为了竞争食物资源的觅食合作是雌性聚群的主要动力。研究她们如何通过合作获得食物资源的机制，不仅是解决物种社群形成机制的重要内容，也是研究合作行为本身进化的关键问题。亲缘关系和等级关系是促进合作形成的两个重要因素，但是二者如何相互作用对群内合作形成的机制并不清楚。通过完善合作机制研究中不对称性和社会结构分层的假设条件，我们推测雌性合作策略可能由食物压力、社会关系和社群结构三个因素共同决定。因此，我们假设食物压力变化将导致雌性的合作策略在不同社会关系的群体内和群体间发生改变，从而使得资源重新分配。本课题拟在此基础上，分析在不同食物压力条件下合作关系的即时变化规律和长期效应，研究雌性个体和群体在食物竞争中的合作行为策略及其变化规律，探索食物资源在重层社会灵长类种群内配置的机制，进而回答雌性合作的形成与进化这一重要理论问题，同时也为该珍稀物种的保护和饲养管理提供指导。

The females of some animal species live in small, close-knit groups that compete for limited resources, such as food, with other intra-specific groups. Females may thus cooperate with other members of their group when also competing with other groups. Understanding why females play both roles requires identifying factors that: i) increase the likelihood of individuals forming intra-group alliances, and ii) results in inter-group competition. Within groups, individuals are more likely to form alliances with close kin, and between groups competitive behaviour for food will be affected by variation in the absolute value of the food resource and any additional costs such as the likelihood of predation. However, theoretical predictions of competition/cooperation are often based on an assumption of symmetric interactions between individuals in a single population. In more complex hierarchical societies, such as in humans and some non-human primates, interactions between individuals occur at multiple levels. We predict that relatedness, social hierarchy and social structure will determine within-group cooperation. Variation in the sizes, quality of food patches, and variation in their degree of exposure to potential predators, will likely affect variation in any collective within-group cooperation, that will in-turn affect the likelihood of inter-group competition. We will test these predictions in a well-known wild primate species, the golden snub-nosed monkey, which has complex multi-level social behaviour. We will conduct food provisioning experiments that will include variation in absolute food quality and the degree of exposure to potential predators, to monkeys of known genetic pedigree and within- and between-group social hierarchies. This work will reveal new insight into the dynamics of cooperation and competition in a complex multi-level primate society, provide a greater understanding of social evolution, and provide additional information to aid primate population management and conservation.