Data from: Resource availability, but not polyandry, influences sibling conflict in a burying beetle Nicrophorus vespilloides

Conflict over resources is a fundamental component of family life. Family conflicts are predicted to be strongly influenced by resource availability and levels of relatedness between family members. Here, we examined the effects of these factors on intra-brood sibling conflict in a family living beetle, Nicrophorus vespilloides, where offspring are partially dependent on parental provisioning. Specifically, we measured the intensity of offspring begging behavior in response to experimental manipulation of 1) relatedness between siblings (through mating females monogamously or polyandrously) and 2) resource availability (through varying the amount of resources at the onset of breeding). We found no effect of polyandry on sibling conflict or patterns of female reproductive investment, but we did find that sibling conflict was influenced by resource availability. Specifically, larvae spent more time begging on smaller carcasses, but only in smaller clutches. In addition, we found that resource availability affected patterns of female reproductive investment: when resource availability was low, females laid eggs more synchronously and produced fewer eggs but of a larger size. We discuss potential explanations for these results, and the implications of this study for understanding the factors that mediate family dynamics.资源争夺是家庭生活的核心构成要素。理论研究表明，家庭冲突极易受资源可获得性与家庭成员间亲缘关系水平的显著影响。本研究以营社会家庭生活的埋葬甲（Nicrophorus vespilloides）为实验对象，该物种的子代部分依赖亲代抚育（parental provisioning），我们借此考察了上述两类因素对其同窝同胞冲突（intra-brood sibling conflict）的影响。具体而言，我们通过两种实验操控手段量化子代乞食行为的强度，以此反映同胞冲突水平：其一为通过让雌虫进行单配制或一妻多夫制交配，以改变同胞间的亲缘关系水平；其二为通过调控繁殖起始阶段的资源供给量，改变资源可获得性。研究结果显示，一妻多夫制交配并未对同胞冲突或雌虫的繁殖投入模式产生显著影响，但资源可获得性确实会影响同胞冲突。具体而言，仅在产卵窝较小时，幼虫在更小的腐尸资源上花费的乞食时间更长。此外，我们还发现资源可获得性会影响雌虫的繁殖投入模式：当资源可获得性较低时，雌虫的产卵同步性更高，产下的卵数量更少但单卵体积更大。我们最后讨论了本研究结果的潜在解释，以及该研究对解析调控家庭动态的相关因素的启示意义。