Data from: Biparental care is predominant and beneficial to parents in the burying beetle Nicrophorus orbicollis (Coleoptera: Silphidae)

Parenting strategies can be flexible within a species, and may have varying fitness effects. Understanding this flexibility and its fitness consequences is important for understanding why parenting strategies evolve. Here, we investigate the fitness consequences of flexible parenting in the burying beetle Nicrophorus orbicollis, a species known for its advanced provisioning behaviour of regurgitated vertebrate carrion to offspring by both sexes. We show that even when a parent is freely allowed to abandon the carcass at any point in time, biparental post-hatching care is the most common pattern of care adopted in N. orbicollis. Furthermore, two parents together raised more offspring than single parents of either sex, showing that the presence of the male can directly influences parental fitness even in the absence of competitors. This contrasts with studies in other species of burying beetle, where biparental families do not differ in offspring number. This may explain why biparental care is more common in N. orbicollis than in other burying beetles. We suggest how fitness benefits of two parents may play a role in the evolution and maintenance of flexible biparental care in N. orbicollis.

同一物种内的育幼策略可具有灵活性，且对适合度（fitness）的影响存在差异。解析此类灵活性及其适合度后果，对于理解育幼策略的演化机制至关重要。本研究以双斑埋葬甲（Nicrophorus orbicollis）为研究对象——该物种因雌雄双亲均可向后代反哺脊椎动物腐肉的高级抚育行为而为人熟知——探讨了灵活育幼策略的适合度后果。研究结果显示，即便允许亲代在任意时间自由放弃腐肉巢块，孵化后双亲抚育仍是双斑埋葬甲最常见的育幼模式。此外，相较于任意性别的单亲抚育个体，双亲抚育可养育更多后代，表明即便在无竞争者的环境中，雄性配偶的存在仍可直接提升亲代的适合度。这一结论与其他埋葬甲物种的相关研究结果相悖：后者的双亲家庭与单亲家庭的后代数量并无显著差异。这或许可以解释为何双斑埋葬甲的双亲抚育行为比其他埋葬甲虫更为普遍。我们据此提出，双亲共同抚育的适合度收益，可能在双斑埋葬甲灵活双亲抚育行为的演化与维持过程中发挥了关键作用。