Data from: Effects of prior contest experience and contest outcome on female reproductive decisions and offspring fitness

Winning or losing a prior contest can influence the outcome of subsequent contests, but it might also alter subsequent reproductive decisions. For example, losers may increase their investment in the current breeding attempt if losing a contest indicates limited prospects for future breeding. Using the burying beetle Nicrophorus vespilloides, we tested whether females adjust their pre-hatching and post-hatching reproductive effort after winning or losing a contest with a same-sex conspecific. N. vespilloides breeds on carcasses of small vertebrates for which there is fierce intrasexual competition. We found no evidence that contest outcome influenced reproductive investment decisions in this species. Instead, we show that a female's prior contest experience, regardless of its outcome, influenced the amount of posthatching care provided, with downstream consequences for the female's reproductive output. Winners and losers spent more time provisioning food to their offspring and produced larger broods than females with no contest experience. We discuss the wider implications of our findings and present a conceptual model linking contest-mediated adjustments in parental investment to population-level processes. We propose that the frequency of intraspecific contests could both influence and be influenced by population dynamics in species where contest experience influences the size and/or number of offspring produced.

先前竞赛的胜负不仅会影响后续竞赛的结果，还可能改变后续的繁殖决策。例如，若竞赛失利预示着未来繁殖机会有限，失利个体或会提升当前繁殖尝试中的资源投入。本研究以埋葬甲（Nicrophorus vespilloides）为实验对象，检验了雌性个体在与同性同类发生竞赛后，是否会调整其孵化前与孵化后的繁殖投入。该物种以小型脊椎动物的腐尸为繁殖场所，此类场景下存在激烈的种内同性竞争。研究未发现该物种的繁殖投入决策受竞赛结果影响的证据。与之相反，雌性个体的先前竞赛经历（无论胜负）均会影响其孵化后的育幼时长，并对雌性的繁殖产出产生下游连锁效应。相较于无竞赛经历的雌性，获胜者与失利者均会花费更多时间为后代提供食物，并培育出规模更大的幼虫集群。我们讨论了本研究发现的更广泛生态学意义，并构建了一个概念模型，将竞赛介导的亲本投入调整与种群水平过程建立关联。我们提出，在那些竞赛经历会影响后代体型和/或后代数量的物种中，种内竞赛的频率既可能影响种群动态，也会反过来受种群动态的影响。