Causes, mechanisms and consequences of female competition in red-fronted lemurs

在哺乳动物繁殖的背景下，女性竞争比经典性别角色理论所假设的要普遍得多。在食肉动物中，雌性动物之间的偶发性目标攻击行为可能导致驱逐甚至死亡，这一行为已经得到了深入的研究，但对灵长类动物的全面实地研究还很缺乏。在这里，我们建议在性别和社会选择理论的框架内对女性竞争的原因、机制和后果进行实地研究。在马达加斯加的一种群居灵长类动物（红额狐猴，Eulemur rufifrons）中，有亲缘关系的雌性经常被驱逐出它们的出生群体，这种激烈的攻击形式的受害者无法加入或组建其他群体，可能导致它们过早死亡。通过将该物种的长期人口统计数据与行为和生理数据相结合，我们将(1)评估社会选择和性选择在形成竞争机制方面的相对重要性，以阐明女性竞争的原因；(2)表征攻击受害者和行动者的社会和生理表型，以解决女性竞争的机制；(3)对比两性之间的生殖倾斜模式，以了解其进化后果。通过对比雌性竞争模式和雄性迁移模式，通过研究它们之间潜在的相互依赖关系，通过利用群体之间的行为变化以及季节之间的生态变化，我们将有助于对进化上令人困惑的现象以及社会选择和性选择之间的相互作用有更精确的理解。

In the context of mammalian reproduction, female competition is much more pervasive than assumed by classical sex role theory. Episodic targeted aggression among females, which may result in eviction and even death, has been intensively studied in carnivores, but comprehensive field studies of primates are lacking. Here we propose to conduct a field study of the causes, mechanisms and consequences of female competition within the frameworks of sexual and social selection theory. In a group-living primate from Madagascar (red-fronted lemurs, Eulemur rufifrons), related females are regularly evicted from their natal group, and the victims of this intense form of aggression are unable to join or form other groups, presumably resulting in their premature death. By combining long-term demographic with behavioral and physiological data from this species, we will (1) evaluate the relative importance of social selection and sexual selection in shaping competitive regimes to illuminate causes of female competition, (2) characterize social and physiological phenotypes of victims and actors of aggression to address mechanisms of female competition, and (3) contrast patterns of reproductive skew between the sexes to understand its evolutionary consequences. By also contrasting patterns of female competition with male emigration, by examining their potential interdependence, and by exploiting behavioral variation among groups as well as ecological variation among seasons, we will contribute to a refined understanding of an evolutionarily puzzling phenomenon and the interplay between social and sexual selection.