Data from: Differences in patterns of reproductive allocation between the sexes in Nicrophorus orbicollis

Organisms are selected to maximize lifetime reproductive success by balancing the costs of current reproduction with costs to future survival and fecundity. Males and females typically face different reproductive costs, which makes comparisons of their reproductive strategies difficult. Burying beetles provide a unique system that allows us to compare the costs of reproduction between the sexes because males and females are capable of raising offspring together or alone and carcass preparation and offspring care represent the majority of reproductive costs for both sexes. Because both sexes perform the same functions of carcass preparation and offspring care, we predict that they would experience similar costs and have similar life history patterns. In this study we assess the cost of reproduction in male Nicrophorus orbicollis and compare to patterns observed in females. We compare the reproductive strategies of single males and females that provided pre- and post-hatching parental care. There is a cost to reproduction for both males and females, but the sexes respond to these costs differently. Females match brood size with carcass size, and thus maximize the lifetime number of offspring on a given size carcass. Males cull proportionately more offspring on all carcass sizes, and thus have a lower lifetime number of offspring compared to females. Females exhibit an adaptive reproductive strategy based on resource availability, but male reproductive strategies are not adaptive in relation to resource availability.生物通过权衡当前繁殖的代价与未来存活及繁殖力的代价，从而实现终生繁殖成功率的最大化。通常雌雄个体面临的繁殖代价存在差异，这使得二者繁殖策略的比较研究颇具难度。埋葬甲（Burying beetles）提供了独特的研究体系，可用于比较雌雄两性的繁殖代价：雌雄个体既能共同抚育后代，也可单独育幼，且尸体准备与子代抚育构成了两性主要的繁殖代价。由于两性均承担尸体准备与子代抚育的相同职能，我们推测二者将面临相似的繁殖代价，并拥有相近的生活史特征。本研究针对雄性圆胸埋葬甲（Nicrophorus orbicollis）的繁殖代价展开评估，并与雌性个体的相关模式进行对比。我们对单独抚育子代（提供孵化前与孵化后双亲抚育）的雌雄个体的繁殖策略进行了比较。研究表明，两性均需付出繁殖代价，但二者对这些代价的响应模式存在差异：雌性会将窝仔数与尸体大小相匹配，从而在特定大小的尸体上最大化终生子代产量；而在所有大小的尸体上，雄性均会按比例淘汰更多子代，因此其终生子代产量较雌性更低。雌性展现出基于资源可获得性的适应性繁殖策略，而雄性的繁殖策略则与资源可获得性不存在适应性关联。