Group size and reproductive success of female and male blue monkeys

社会性是灵长类的一个标志，而理解群体生活的选择优势已经被证明是一个持久的问题。 研究人员正在研究肯尼亚卡卡梅加雨林中的六组野生蓝猴（Cercopithecus mitas stuhlmanni），它们的大小相差五倍，以了解群体生活的进化基础。这个项目的重点是群体大小的变化如何影响野生雌性和雄性蓝猴的生物适应性。团体的规模预计将反映出团体生活对个人团体成员的成本和收益。 雌性会积极地与群体成员争夺食物，当群体变大时，会导致群体分裂。这样的观察表明，生活在更大的群体中是有代价的，而集体的领土和捕食者防御，主要是由女性，也表明了好处。研究小组调查了群体规模如何影响女性健康，直接从生育间隔、婴儿存活率和首次生育年龄方面进行测量，间接从喂养和社会行为方面进行测量。 这种物种的雄性试图垄断雌性群体，在更大的群体中应该有更多的繁殖机会。男性生殖分区模型提出了其他重要的因素，但是，像女性生殖同步，入侵者的压力和男性自己的生殖历史。这个项目澄清了哪些因素最能解释雄性之间生殖的巨大差异。 研究人员监测人口变化，女性社会和性行为，并收集粪便样本，使用微卫星位点进行遗传亲子鉴定。研究人群是极少数存在长期人口统计数据的人群之一。 该项目直接测量与社会和生态驱动因素相关的生殖结果。该项目支持一名女研究生的论文研究，以及其他本科生，硕士，和博士学生 与一所新的肯尼亚大学的国际合作导致建立了与实地有关的森林生态学专门知识;项目人员支持一个基层社区保护组织，并向正在为卡卡梅加森林制定参与性管理计划的科学小组提供咨询意见。

Sociality is a hallmark of the primate order, and understanding the selective advantage of group living has proved an enduring question. The researchers are studying six groups of wild blue monkeys (Cercopithecus mitas stuhlmanni), differing five-fold in size, in the Kakamega, Kenya rain forest to understand the evolutionary basis of group living. This project focuses on how variation in group size influences biological fitness in of wild female and male blue monkeys. Group size is expected to reflect costs and benefits of group living to individual group members. Females compete aggressively with group-mates over access to food, and engineer group splits when groups become large. Such observations suggest costs to living in larger groups, while collective territorial and predator defense, mainly by females, also suggests benefits. The research team investigates how group size influences female fitness, measured directly in terms of inter-birth interval, infant survival, and age at first birth, and indirectly by aspects of feeding and social behavior. Males of this species try to monopolize groups of females, and should have more reproductive opportunities in larger groups. Models of male reproductive partitioning suggest additional important factors, however, like female reproductive synchrony, intruder pressure and a male's own reproductive history. This project clarifies which factors best explain the considerable variation in reproduction among males. The researchers monitor demographic changes, female social and sexual behavior, and collect fecal samples for genetic paternity assignment using microsatellite loci. The study population is one of very few in which long-term demographic data exist. This project directly measures reproductive outcomes as related to social and ecological drivers.This project supports the dissertation research of a female graduate student, and research training of other undergraduate, M.A., and Ph.D. students. International collaboration with a new Kenyan university has led to building expertise in forest ecology related to the field site; the project personnel support a grass-roots community-based conservation organization, and advise the scientific team that is developing the participatory management plan for the Kakamega Forest.