Kalbitzer Urs, Bergstrom Mackenzie L, Carnegie Sarah D, Wikberg Eva C, Kawamura Shoji, Campos Fernando A, Jack Katharine M, Fedigan Linda M
Department of Anthropology and Archaeology, University of Calgary, Calgary, AB, Canada T2N 1N4;
Department of Anthropology and Archaeology, University of Calgary, Calgary, AB, Canada T2N 1N4.
Proc Natl Acad Sci U S A. 2017 Feb 21;114(8):1892-1897. doi: 10.1073/pnas.1608625114. Epub 2017 Feb 6.
Most mammals live in social groups in which members form differentiated social relationships. Individuals may vary in their degree of sociality, and this variation can be associated with differential fitness. In some species, for example, female sociality has a positive effect on infant survival. However, investigations of such cases are still rare, and no previous study has considered how male infanticide might constrain effects of female sociality on infant survival. Infanticide is part of the male reproductive strategy in many mammals, and it has the potential to override, or even reverse, effects of female reproductive strategies, including sociality. Therefore, we investigated the relationships between female sociality, offspring survival, and infanticide risk in wild white-faced capuchin monkeys using long-term data from Santa Rosa, Costa Rica. Female capuchins formed differentiated bonds, and bond strength was predicted by kin relationship, rank difference, and the presence of female infants. Most females formed stable bonds with their top social partners, although bond stability varied considerably. Offspring of highly social females, who were often high-ranking females, exhibited higher survivorship during stable periods compared with offspring of less social females. However, offspring of highly social females were more likely to die or disappear during periods of alpha male replacements, probably because new alpha males are central to the group, and therefore more likely to target the infants of highly social, central females. This study shows that female sociality in mammals can have negative fitness consequences that are imposed by male behavior.
大多数哺乳动物生活在社会群体中，群体成员形成了不同的社会关系。个体的社会性程度可能有所不同，这种差异可能与不同的适应性相关。例如，在某些物种中，雌性的社会性对幼崽的存活有积极影响。然而，对这类情况的研究仍然很少，而且以前没有研究考虑过雄性杀婴行为可能如何限制雌性社会性对幼崽存活的影响。杀婴行为是许多哺乳动物雄性生殖策略的一部分，它有可能推翻甚至逆转包括社会性在内的雌性生殖策略的影响。因此，我们利用来自哥斯达黎加圣罗莎的长期数据，研究了野生白面卷尾猴中雌性社会性、后代存活和杀婴风险之间的关系。雌性卷尾猴形成了不同的联系，联系强度由亲缘关系、等级差异和雌性幼崽的存在来预测。大多数雌性与它们的主要社会伙伴形成了稳定的联系，尽管联系的稳定性差异很大。与社会性较低的雌性后代相比，社会性高的雌性（通常是高等级雌性）的后代在稳定时期表现出更高的存活率。然而，在雄性首领更替期间，社会性高的雌性后代更有可能死亡或消失，这可能是因为新的雄性首领处于群体核心位置，因此更有可能将目标对准社会性高的核心雌性的幼崽。这项研究表明，哺乳动物中的雌性社会性可能会产生由雄性行为导致的负面适应性后果。
