A cost of being amicable in a hibernating marmot

Amicable social interactions can enhance fitness in many species, have negligible consequences for some, and reduce fitness in others. For yellow-bellied marmots (Marmota flaviventris), a facultatively social rodent species with demonstrable costs of social relationships during the active season, the effects of sociality on overwinter survival have yet to be fully investigated. Here, we explored how summer social interactions, quantified as social network attributes, influenced marmot survival during hibernation. Using social data collected from 2002 to 2012 on free-living yellow-bellied marmots, we calculated 8 social network measures (in-degree, out-degree, in-closeness, out-closeness, in-strength, out-strength, embeddedness, and clustering coefficient) for both affiliative and agonistic interactions. We performed a principal component analysis (PCA) to reduce those attributes to 3 affiliative (connectedness, strength, and clustering) and 4 agonistic (submissiveness, bullying, strengt...亲和性社会互动可提升诸多物种的适合度（fitness），对部分物种影响甚微，却会降低另一些物种的适合度。对于兼性社会性啮齿类动物黄腹旱獭（Marmota flaviventris）而言，其活动季内的社会关系已被证实存在代价，但社会性对其越冬存活的影响仍有待全面探明。本研究探讨了以社会网络属性量化的夏季社会互动如何影响黄腹旱獭冬眠期间的存活情况。我们利用2002年至2012年间采集的野生黄腹旱獭社会互动数据，针对亲和性与对抗性两类互动分别计算了8项社会网络指标：入度（in-degree）、出度（out-degree）、入亲近度（in-closeness）、出亲近度（out-closeness）、入强度（in-strength）、出强度（out-strength）、嵌入度（embeddedness）以及聚类系数（clustering coefficient）。我们通过主成分分析（principal component analysis, PCA）将上述属性降维为3项亲和性指标（连通性、强度与聚类性）以及4项对抗性指标（顺从性、霸凌行为、强度[原文截断]……）