Queen-worker ratio affects reproductive skew in a socially polymorphic ant

The partitioning of reproduction among individuals in communally breeding animals varies greatly among species, from the monopolization of reproduction (high reproductive skew) to similar contribution to the offspring in others (low skew). Reproductive skew models explain how relatedness or ecological constraints affect the magnitude of reproductive skew. They typically assume that individuals are capable of flexibly reacting to social and environmental changes. Most models predict a decrease of skew when benefits of staying in the group are reduced. In the ant Leptothorax acervorum, queens in colonies from marginal habitats form dominance hierarchies and only the top-ranking queen lays eggs (“functional monogyny”). In contrast, queens in colonies from extended coniferous forests throughout the Palaearctic rarely interact aggressively and all lay eggs (“polygyny”). An experimental increase of queen:worker ratios in colonies from low-skew populations elicits queen–queen aggression simila...

群居繁殖动物的个体间繁殖资源分配在不同物种间差异显著，从完全垄断繁殖机会的高繁殖偏斜(Reproductive Skew)，到个体间繁殖投入近乎均等的低繁殖偏斜均有分布。繁殖偏斜模型旨在阐释亲缘关系或生态限制因素如何影响繁殖偏斜的程度。这类模型通常假定个体能够灵活响应社会与环境变化。多数模型预测，当留在种群中的收益下降时，繁殖偏斜程度会降低。在尖扁胸切叶蚁（Leptothorax acervorum）中，源自边缘生境的蚁群内的蚁后会形成优势等级，仅最高等级的蚁后负责产卵（即"功能单雌制(Functional Monogyny)"）。与之相反，分布于整个古北界连片针叶林的蚁群内的蚁后极少发生攻击性互动，所有蚁后均可产卵（即"多雌制(Polygyny)"）。对低繁殖偏斜种群的蚁群进行蚁后与工蜂比例的实验性上调时，会引发蚁后间的攻击性互动，类似...