Hellmann Jennifer K, Hamilton Ian M
Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, USA.
Department of Mathematics, The Ohio State University, Columbus, OH, USA.
Curr Zool. 2019 Feb;65(1):21-31. doi: 10.1093/cz/zoy025. Epub 2018 Apr 5.
Conflict is an inherent part of social life in group-living species. Group members may mediate conflict through submissive and affiliative behaviors, which can reduce aggression, stabilize dominance hierarchies, and foster group cohesion. The frequency and resolution of within-group conflict may vary with the presence of neighboring groups. Neighbors can threaten the territory or resources of the whole group, promoting behaviors that foster within-group cohesion. However, neighbors may also foster conflict of interests among group members: opportunities for subordinate dispersal may alter conflict among dominants and subordinates while opportunities for extra-pair reproduction may increase conflict between mates. To understand how neighbors mediate within-group conflict in the cooperatively breeding fish , we measured behavioral dynamics and social network structure in isolated groups, groups recently exposed to neighbors, and groups with established neighbors. Aggression and submission between the dominant male and female pair were high in isolated groups, but dominant aggression was directly primarily at subordinates when groups had neighbors. This suggests that neighbors attenuate conflict between mates and foster conflict between dominants and subordinates. Further, aggression and submission between similarly sized group members were most frequent when groups had neighbors, suggesting that neighbors induce rank-related conflict. We found relatively little change in within-group affiliative networks across treatments, suggesting that the presence of neighbors does not alter behaviors associated with promoting group cohesion. Collectively, these results provide some of the first empirical insights into the extent to which intragroup behavioral networks are mediated by intergroup interactions and the broader social context.
冲突是群居物种社会生活中固有的一部分。群体成员可以通过顺从和亲和行为来调解冲突，这可以减少攻击行为、稳定优势等级制度并促进群体凝聚力。群体内部冲突的频率和解决方式可能会因相邻群体的存在而有所不同。邻居可能会威胁到整个群体的领地或资源，从而促使群体采取增强内部凝聚力的行为。然而，邻居也可能会加剧群体成员之间的利益冲突：从属个体扩散的机会可能会改变优势个体和从属个体之间的冲突，而额外配对繁殖的机会可能会增加配偶之间的冲突。为了了解邻居如何调解合作繁殖鱼类的群体内部冲突，我们测量了孤立群体、最近接触过邻居的群体以及有固定邻居的群体中的行为动态和社会网络结构。在孤立群体中，占主导地位的雌雄配对之间的攻击和顺从行为较多，但当群体有邻居时，主导个体的攻击主要直接针对从属个体。这表明邻居会减轻配偶之间的冲突，并加剧主导个体和从属个体之间的冲突。此外，当群体有邻居时，体型相似的群体成员之间的攻击和顺从行为最为频繁，这表明邻居会引发与等级相关的冲突。我们发现不同处理组之间群体内部的亲和网络变化相对较小，这表明邻居的存在不会改变与促进群体凝聚力相关的行为。总体而言，这些结果为群体间互动和更广泛的社会背景在多大程度上介导群体内部行为网络提供了一些初步的实证见解。
