Behavioral determinants and consequences of the natural spread of a sexuallytransmitted disease in wild olive baboons (Papio anubis)

性传播疾病是影响哺乳动物免疫防御进化的主要生态力量，也可能对交配系统的进化产生影响。尽管性传播疾病在种群中的传播在很大程度上取决于物种的交配行为，即交配伴侣的数量和每个伴侣的交配次数，但在很大程度上仍不清楚动物，如非人类灵长类动物，是否已经制定了适应性应对策略，以应对性病风险或获得性的增加。这种应对策略包括卫生行为，如交配后自我清洁生殖器或排尿，改变配偶选择，偏好未感染的配偶，这可能导致群居灵长类动物迁移到未感染的群体中。在我们的项目中，我们将调查坦桑尼亚曼雅拉湖国家公园（LMNP）的橄榄狒狒（Papio anubis）种群。橄榄狒狒生活在相对较大的社会群体中，原则上表现出滥交的交配行为。lmnp种群受梅毒螺旋体细菌感染，该细菌在人类和狒狒中引起几种疾病（例如梅毒），在雄性和雌性中造成巨大的、非常明显的生殖器溃疡。这些溃疡表明这些人被感染了。梅毒螺旋体很可能是通过性接触传播的。为了测试配偶选择和交配后的行为是否会因潜在交配伴侣的明显感染迹象而改变，我们将定量分析交配行为（例如交配伴侣的数量、性接触的次数）、性交后的自我梳理、交配后的排尿与各自交配伴侣的健康状况的关系。作为可能影响配偶选择和交配策略的辅助因素，我们将包括优势等级、年龄（男性和女性）以及女性的生殖状态。这些数据将用于构建一个代表性病传播潜在途径的交配网络。在一个模拟模型中，我们将从LMNP的狒狒种群调查中收集网络和性病避免行为以及狒狒人口统计数据，并从文献中收集其他一般狒狒生活史数据，我们将能够评估长期疾病动态。利用模拟模型的输出，我们将确定观察到的狒狒种群中超级传播者的关键社会和人口特征，值得注意的是，该模型最终可用于预测要治疗的狒狒的最小数量，以使种群低于流行病阈值。

Sexually transmitted diseases (STDs) represent a major ecological force in shaping the evolution of mammalian immune defences and additionally might have an impact on the evolution of mating systems. Whereas the spread of STDs in a population largely depends on the mating behaviour of a species, i.e. the number of mating partners and the number of matings per partner, it remains largely unknown whether animals, such as nonhuman primates have developed adaptive counterstrategies in response to increased STD-risk or acquisition. Such counterstrategies can involve hygienic behaviours, such as post-copulatory self-cleaning of genitals or urination, change in mate choice with a preference for non-infected mating partners, which might, in case of gregarious primates lead even to a migration into noninfected groups.In our project we will investigate a population of olive baboons (Papio anubis) at Lake Manyara National Park (LMNP) in Tanzania. Olive baboons live in relatively large social groups and show, in principle, a promiscuous mating behaviour. The LMNP-population is infected by the bacterium Treponema pallidum which causes several diseases in humans (e.g. syphilis) and in baboons massive, highly conspicuous genital ulcerations in males and females. These ulcerations signal that such individuals are infected. Most likely T. pallidum is transmitted by sexual contacts. To test whether mate choice and post-copulatory behaviour are altered by visible sign of infection in potential mating partners, we will quantitatively analyse mating behaviour (e.g. number of mating partner, number of sexual contacts), postcoital self-grooming, post-copulatory urination in relation to the health status of the respective mating partner. As possible co-factors influencing mate choice and mating strategies, we will include dominance rank, age (males and females) and in females also reproductive state. The data will be used to construct a mating network that represents potential routes for STD spread. In a simulation model, which incorporates network and STD avoidance behaviour and baboon demographic data, which we will gather from baboon population surveys in LMNP and additional general baboon life history data from the literature, we will be able to assess longterm disease dynamics. Using outputs from simulation model we will identify key social and demographic characteristics of superspreaders in the observed baboon population, and notably, this model could ultimately be used to predict the minimum number of baboons to treat in order to bring the population below epidemic threshold.