The tolerant chimpanzee - Quantifying costs and benefits of sociality in wild female bonobos (Pan paniscus)

个人的社交方式被认为对健康有直接的影响。因此，动物只有在向个体传递净利益的情况下才能生活在有凝聚力的群体中，只有在强大的纽带增加繁殖成功的情况下，个体才会形成不同的社会纽带。虽然这是行为生态学中的一个重要论点，但大型、慢速生活的哺乳动物的证据积累得很慢。这项研究的具体目的是测试将食物资源中的社会互动与由此产生的压力反应和能量后果联系起来的预测。我们的方法结合了(A)新的焦点树观察方法和(B)产生高时间分辨率能量平衡的新的野外内分泌学方法。通过这种方法，可以根据促进生存和繁殖的个体能量平衡的变化来衡量重复社会互动的累积适应收益。这项研究的目的是评估关于社会特征进化的相互竞争的假说，比如社会宽容和社会性行为，侏儒黑猩猩或矮黑猩猩与工业化前的人类共享，但与普通黑猩猩不同。因此，这项关于黑猩猩自然栖息地中唯一习惯性的非供应群落的研究有望揭示人类社会行为的进化。

The way individuals socialize is thought to have direct fitness consequences. Accordingly, animals live in cohesive groups only if it conveys net benefits to the individual and individuals form differential social bonds only if strong bonds increase reproductive success. Although this is a hall mark argument in behavioral ecology evidence for large, slow living mammals is accumulating only slowly. The specific aim of the study is to test predictions linking social interactions in food resources to the resulting stress response and energetic consequences. Our approach combines (a) new focal tree observation methods and (b) new field endocrinological methods that yield high temporal resolution of energy balance. With this approach the cumulative adaptive benefit of repeated social interactions can be measured in terms of variation in individual energy balance promoting survival and reproduction. The goal of the study is to evaluate competing hypotheses for the evolution of social traits like social tolerance and socio-sexual behaviors that pygmy chimpanzees or bonobos share with pre-industrial humans but not with common chimpanzees. Thus, this study on the only habituated nonprovisioned community of bonobos in their natural habitat promises to shed light on the evolution of human social behavior.