Bose Aneesh P H, Dabernig-Heinz Johanna, Oberkofler Jan, Koch Lukas, Grimm Jacqueline, Sefc Kristina M, Jordan Alex
Department of Wildlife, Fish & Environmental Studies, Swedish University of Agricultural Sciences (SLU), Skogsmarksgränd, 90183, Umeå, Sweden.
Department of Collective Behaviour, Max Planck Institute of Animal Behavior, Universitätsstraße 10, 78464, Konstanz, Germany.
Behav Ecol. 2023 May 12;34(4):673-681. doi: 10.1093/beheco/arad036. eCollection 2023 Jul-Aug.
Group-living animals are faced with the challenge of sharing space and local resources amongst group members who may be either relatives or non-relatives. Individuals may reduce the inclusive fitness costs they incur from competing with relatives by either reducing their levels of aggression toward kin, or by maintaining physical separation between kin. In this field study, we used the group-living cichlid to examine whether within-group aggression is reduced among group members that are kin, and whether kin occupy different regions of their group's territory to reduce kin competition over space and local resources. We determined the kinship relationships among cohabiting adults via microsatellite genotyping and then combined these with spatial and behavioral analyses of groups in the wild. We found that aggressive contests between group members declined in frequency with spatial separation between their shelters. Female kin did not engage in aggressive contests with one another, whereas non-kin females did, despite the fact these females lived at similar distances from one another on their groups' territories. Contests within male-male and male-female dyads did not clearly correlate with kinship. Non-kin male-male and male-female dyads lived at more variable distances from one another on their territories than their corresponding kin dyads. Together, our study indicates that contests among group members can be mediated by relatedness in a sex-dependent manner. We also suggest that spatial relationships can play an important role in determining the extent to which group members compete with one another.
群居动物面临着在可能是亲属或非亲属的群体成员之间共享空间和当地资源的挑战。个体可以通过降低对亲属的攻击水平，或通过与亲属保持身体上的距离，来减少与亲属竞争所产生的广义适合度成本。在这项实地研究中，我们利用群居丽鱼来检验在亲属群体成员之间，群体内的攻击性是否会降低，以及亲属是否会占据其群体领地的不同区域，以减少对空间和当地资源的亲属竞争。我们通过微卫星基因分型确定了同居成年个体之间的亲属关系，然后将这些关系与野外群体的空间和行为分析相结合。我们发现，群体成员之间的攻击性争斗频率随着它们庇护所之间的空间距离而下降。雌性亲属之间不会相互进行攻击性争斗，而非亲属雌性则会，尽管这些雌性在群体领地内彼此居住的距离相似。雄性与雄性以及雄性与雌性二元组内的争斗与亲属关系没有明显关联。非亲属的雄性与雄性以及雄性与雌性二元组在领地内彼此之间的距离比相应的亲属二元组更具变化性。总之，我们的研究表明，群体成员之间的争斗可以通过亲属关系以性别依赖的方式进行调节。我们还认为，空间关系在决定群体成员相互竞争程度方面可以发挥重要作用。
